Squashed 'features/FEATURE_LWIP/lwip-interface/lwip/' changes from 10f93f4..7648b58

git-subtree-dir: features/FEATURE_LWIP/lwip-interface/lwip
git-subtree-split: 7648b58d03006bd60b9592f1853c167bf52b0193

CHANGELOG

@@ -3,16 +3,91 @@ HISTORY
 (git master)
 
   * [Enter new changes just after this line - do not remove this line]
- 
+
+(STABLE-2.0.2)
+
+  ++ New features:
+
+  2017-02-10: Dirk Ziegelmeier
+  * Implement task #14367: Hooks need a better place to be defined:
+    We now have a #define for a header file name that is #included in every .c
+    file that provides hooks.
+
+  ++ Bugfixes:
+
+  2017-03-08
+  * tcp: do not keep sending SYNs when getting ACKs
+
+  2017-03-08: Joel Cunningham
+  * tcp: Initialize ssthresh to TCP_SND_BUF (bug #50476)
+
+  2017-03-01: Simon Goldschmidt
+  * httpd: LWIP_HTTPD_POST_MANUAL_WND: fixed double-free when httpd_post_data_recved
+    is called nested from httpd_post_receive_data() (bug #50424)
+
+  2017-02-28: David van Moolenbroek/Simon Goldschmidt
+  * tcp: fixed bug #50418: LWIP_EVENT_API: fix invalid calbacks for SYN_RCVD pcb
+
+  2017-02-17: Simon Goldschmidt
+  * dns: Improved DNS_LOCAL_HOSTLIST interface (bug #50325)
+
+  2017-02-16: Simon Goldschmidt
+  * LWIP_NETCONN_FULLDUPLEX: fixed shutdown during write (bug #50274)
+
+  2017-02-13: Simon Goldschmidt/Dirk Ziegelmeier
+  * For tiny targtes, LWIP_RAND is optional (fix compile time checks)
+
+  2017-02-10: Simon Goldschmidt
+  * tcp: Fixed bug #47485 (tcp_close() should not fail on memory error) by retrying
+    to send FIN from tcp_fasttmr
+
+  2017-02-09: Simon Goldschmidt
+  * sockets: Fixed bug #44032 (LWIP_NETCONN_FULLDUPLEX: select might work on
+    invalid/reused socket) by not allowing to reallocate a socket that has
+    "select_waiting != 0"
+
+  2017-02-09: Simon Goldschmidt
+  * httpd: Fixed bug #50059 (httpd LWIP_HTTPD_SUPPORT_11_KEEPALIVE vs.
+    LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED)
+
+  2017-02-08: Dirk Ziegelmeier
+  * Rename "IPv6 mapped IPv4 addresses" to their correct name from RFC4191:
+    "IPv4-mapped IPv6 address"
+
+  2017-02-08: Luc Revardel
+  * mld6.c: Fix bug #50220 (mld6_leavegroup does not send ICMP6_TYPE_MLD, even
+    if last reporter)
+
+  2017-02-08: David van Moolenbroek
+  * ip6.c: Patch #9250: fix source substitution in ip6_output_if()
+
+  2017-02-08: Simon Goldschmidt
+  * tcp_out.c: Fixed bug #50090 (last_unsent->oversize_left can become wrong value
+    in tcp_write error path)
+
+  2017-02-02: Dirk Ziegelmeier
+  * Fix bug #50206: UDP Netconn bind to IP6_ADDR_ANY fails
+
+  2017-01-18: Dirk Ziegelmeier
+  * Fix zero-copy RX, see bug bug #50064. PBUF_REFs were not supported as ARP requests.
+
+  2017-01-15: Axel Lin, Dirk Ziegelmeier
+  * minor bug fixes in mqtt
+
+  2017-01-11: Knut Andre Tidemann
+  * sockets/netconn: fix broken default ICMPv6 handling of checksums
+
+(STABLE-2.0.1)
+
   ++ New features:
 
   2016-12-31: Simon Goldschmidt
   * tcp.h/.c: added function tcp_listen_with_backlog_and_err() to get the error
     reason when listening fails (bug #49861)
 
-  2016-12-20: Erik Andersen
+  2016-12-20: Erik Andersen
-  * Add MQTT client
+  * Add MQTT client
-
+
   2016-12-14: Jan Breuer:
   * opt.h, ndc.h/.c: add support for RDNSS option (as per RFC 6106)
 
@@ -43,7 +118,7 @@ HISTORY
 
   2016-12-05: Dirk Ziegelmeier
   * fixed compiling with IPv4 disabled (IPv6 only case)
-  
+
   2016-11-28: Simon Goldschmidt
   * api_lib.c: fixed bug #49725 (send-timeout: netconn_write() can return
     ERR_OK without all bytes being written)
@@ -72,7 +147,7 @@ HISTORY
   2016-11-11: Dirk Ziegelmeier
   * sockets.c: fixed bug #49578 (dropping multicast membership does not work
     with LWIP_SOCKET_OFFSET)
-  
+
 (STABLE-2.0.0)
 
   ++ New features:

doc/doxygen/lwip.Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = "lwIP"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = "2.0.1"
+PROJECT_NUMBER         = "2.0.2"
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

doc/doxygen/main_page.h

@@ -26,6 +26,11 @@
  * @verbinclude "UPGRADING"
  */
 
+/**
+ * @page changelog Changelog
+ * @verbinclude "CHANGELOG"
+ */
+
 /**
  * @page contrib How to contribute to lwIP
  * @verbinclude "contrib.txt"

src/api/lwip_api_msg.c

@@ -562,6 +562,13 @@ pcb_new(struct api_msg *msg)
   case NETCONN_RAW:
     msg->conn->pcb.raw = raw_new_ip_type(iptype, msg->msg.n.proto);
     if (msg->conn->pcb.raw != NULL) {
+#if LWIP_IPV6
+      /* ICMPv6 packets should always have checksum calculated by the stack as per RFC 3542 chapter 3.1 */
+      if (NETCONNTYPE_ISIPV6(msg->conn->type) && msg->conn->pcb.raw->protocol == IP6_NEXTH_ICMP6) {
+        msg->conn->pcb.raw->chksum_reqd = 1;
+        msg->conn->pcb.raw->chksum_offset = 2;
+      }
+#endif /* LWIP_IPV6 */
       raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
     }
     break;
@@ -1777,25 +1784,28 @@ lwip_netconn_do_close(void *m)
 #if LWIP_NETCONN_FULLDUPLEX
       if (msg->msg.sd.shut & NETCONN_SHUT_WR) {
         /* close requested, abort running write */
-        sys_sem_t* op_completed_sem;
+        sys_sem_t* write_completed_sem;
         LWIP_ASSERT("msg->conn->current_msg != NULL", msg->conn->current_msg != NULL);
-        op_completed_sem = LWIP_API_MSG_SEM(msg->conn->current_msg);
+        write_completed_sem = LWIP_API_MSG_SEM(msg->conn->current_msg);
         msg->conn->current_msg->err = ERR_CLSD;
         msg->conn->current_msg = NULL;
         msg->conn->write_offset = 0;
         msg->conn->state = NETCONN_NONE;
+        state = NETCONN_NONE;
         NETCONN_SET_SAFE_ERR(msg->conn, ERR_CLSD);
-        sys_sem_signal(op_completed_sem);
+        sys_sem_signal(write_completed_sem);
       } else {
         LWIP_ASSERT("msg->msg.sd.shut == NETCONN_SHUT_RD", msg->msg.sd.shut == NETCONN_SHUT_RD);
         /* In this case, let the write continue and do not interfere with
            conn->current_msg or conn->state! */
         msg->err = tcp_shutdown(msg->conn->pcb.tcp, 1, 0);
       }
+    }
+    if (state == NETCONN_NONE) {
 #else /* LWIP_NETCONN_FULLDUPLEX */
       msg->err = ERR_INPROGRESS;
-#endif /* LWIP_NETCONN_FULLDUPLEX */
     } else {
+#endif /* LWIP_NETCONN_FULLDUPLEX */
       if (msg->msg.sd.shut & NETCONN_SHUT_RD) {
         /* Drain and delete mboxes */
         netconn_drain(msg->conn);

src/api/lwip_err.c

@@ -40,7 +40,7 @@
 #include "lwip/def.h"
 #include "lwip/sys.h"
 
-#include "lwip/errno.h"
+#include "lwip/lwip_errno.h"
 
 #if !NO_SYS
 /** Table to quickly map an lwIP error (err_t) to a socket error

src/api/lwip_sockets.c

@@ -407,7 +407,7 @@ alloc_socket(struct netconn *newconn, int accepted)
   for (i = 0; i < NUM_SOCKETS; ++i) {
     /* Protect socket array */
     SYS_ARCH_PROTECT(lev);
-    if (!sockets[i].conn) {
+    if (!sockets[i].conn && (sockets[i].select_waiting == 0)) {
       sockets[i].conn       = newconn;
       /* The socket is not yet known to anyone, so no need to protect
          after having marked it as used. */
@@ -420,7 +420,6 @@ alloc_socket(struct netconn *newconn, int accepted)
       sockets[i].sendevent  = (NETCONNTYPE_GROUP(newconn->type) == NETCONN_TCP ? (accepted != 0) : 1);
       sockets[i].errevent   = 0;
       sockets[i].err        = 0;
-      sockets[i].select_waiting = 0;
       return i + LWIP_SOCKET_OFFSET;
     }
     SYS_ARCH_UNPROTECT(lev);
@@ -585,9 +584,9 @@ lwip_bind(int s, const struct sockaddr *name, socklen_t namelen)
   LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\n", local_port));
 
 #if LWIP_IPV4 && LWIP_IPV6
-  /* Dual-stack: Unmap IPv6 mapped IPv4 addresses */
+  /* Dual-stack: Unmap IPv4 mapped IPv6 addresses */
-  if (IP_IS_V6_VAL(local_addr) && ip6_addr_isipv6mappedipv4(ip_2_ip6(&local_addr))) {
+  if (IP_IS_V6_VAL(local_addr) && ip6_addr_isipv4mappedipv6(ip_2_ip6(&local_addr))) {
-    unmap_ipv6_mapped_ipv4(ip_2_ip4(&local_addr), ip_2_ip6(&local_addr));
+    unmap_ipv4_mapped_ipv6(ip_2_ip4(&local_addr), ip_2_ip6(&local_addr));
     IP_SET_TYPE_VAL(local_addr, IPADDR_TYPE_V4);
   }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -677,9 +676,9 @@ lwip_connect(int s, const struct sockaddr *name, socklen_t namelen)
     LWIP_DEBUGF(SOCKETS_DEBUG, (" port=%"U16_F")\n", remote_port));
 
 #if LWIP_IPV4 && LWIP_IPV6
-    /* Dual-stack: Unmap IPv6 mapped IPv4 addresses */
+    /* Dual-stack: Unmap IPv4 mapped IPv6 addresses */
-    if (IP_IS_V6_VAL(remote_addr) && ip6_addr_isipv6mappedipv4(ip_2_ip6(&remote_addr))) {
+    if (IP_IS_V6_VAL(remote_addr) && ip6_addr_isipv4mappedipv6(ip_2_ip6(&remote_addr))) {
-      unmap_ipv6_mapped_ipv4(ip_2_ip4(&remote_addr), ip_2_ip6(&remote_addr));
+      unmap_ipv4_mapped_ipv6(ip_2_ip4(&remote_addr), ip_2_ip6(&remote_addr));
       IP_SET_TYPE_VAL(remote_addr, IPADDR_TYPE_V4);
     }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -865,9 +864,9 @@ lwip_recvfrom(int s, void *mem, size_t len, int flags,
         }
 
 #if LWIP_IPV4 && LWIP_IPV6
-        /* Dual-stack: Map IPv4 addresses to IPv6 mapped IPv4 */
+        /* Dual-stack: Map IPv4 addresses to IPv4 mapped IPv6 */
         if (NETCONNTYPE_ISIPV6(netconn_type(sock->conn)) && IP_IS_V4(fromaddr)) {
-          ip4_2_ipv6_mapped_ipv4(ip_2_ip6(fromaddr), ip_2_ip4(fromaddr));
+          ip4_2_ipv4_mapped_ipv6(ip_2_ip6(fromaddr), ip_2_ip4(fromaddr));
           IP_SET_TYPE(fromaddr, IPADDR_TYPE_V6);
         }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -995,6 +994,10 @@ lwip_sendmsg(int s, const struct msghdr *msg, int flags)
     ((flags & MSG_DONTWAIT) ? NETCONN_DONTBLOCK : 0);
 
     for (i = 0; i < msg->msg_iovlen; i++) {
+      u8_t apiflags = write_flags;
+      if (i + 1 < msg->msg_iovlen) {
+        apiflags |= NETCONN_MORE;
+      }
       written = 0;
       err = netconn_write_partly(sock->conn, msg->msg_iov[i].iov_base, msg->msg_iov[i].iov_len, write_flags, &written);
       if (err == ERR_OK) {
@@ -1092,9 +1095,9 @@ lwip_sendmsg(int s, const struct msghdr *msg, int flags)
 
     if (err == ERR_OK) {
 #if LWIP_IPV4 && LWIP_IPV6
-      /* Dual-stack: Unmap IPv6 mapped IPv4 addresses */
+      /* Dual-stack: Unmap IPv4 mapped IPv6 addresses */
-      if (IP_IS_V6_VAL(chain_buf->addr) && ip6_addr_isipv6mappedipv4(ip_2_ip6(&chain_buf->addr))) {
+      if (IP_IS_V6_VAL(chain_buf->addr) && ip6_addr_isipv4mappedipv6(ip_2_ip6(&chain_buf->addr))) {
-        unmap_ipv6_mapped_ipv4(ip_2_ip4(&chain_buf->addr), ip_2_ip6(&chain_buf->addr));
+        unmap_ipv4_mapped_ipv6(ip_2_ip4(&chain_buf->addr), ip_2_ip6(&chain_buf->addr));
         IP_SET_TYPE_VAL(chain_buf->addr, IPADDR_TYPE_V4);
       }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -1190,9 +1193,9 @@ lwip_sendto(int s, const void *data, size_t size, int flags,
 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
   if (err == ERR_OK) {
 #if LWIP_IPV4 && LWIP_IPV6
-    /* Dual-stack: Unmap IPv6 mapped IPv4 addresses */
+    /* Dual-stack: Unmap IPv4 mapped IPv6 addresses */
-    if (IP_IS_V6_VAL(buf.addr) && ip6_addr_isipv6mappedipv4(ip_2_ip6(&buf.addr))) {
+    if (IP_IS_V6_VAL(buf.addr) && ip6_addr_isipv4mappedipv6(ip_2_ip6(&buf.addr))) {
-      unmap_ipv6_mapped_ipv4(ip_2_ip4(&buf.addr), ip_2_ip6(&buf.addr));
+      unmap_ipv4_mapped_ipv6(ip_2_ip4(&buf.addr), ip_2_ip6(&buf.addr));
       IP_SET_TYPE_VAL(buf.addr, IPADDR_TYPE_V4);
     }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -1490,9 +1493,7 @@ lwip_select(int maxfdp1, fd_set *readset, fd_set *writeset, fd_set *exceptset,
         SYS_ARCH_PROTECT(lev);
         sock = tryget_socket(i);
         if (sock != NULL) {
-          /* @todo: what if this is a new socket (reallocated?) in this case,
+          /* for now, handle select_waiting==0... */
-             select_waiting-- would be wrong (a global 'sockalloc' counter,
-             stored per socket could help) */
           LWIP_ASSERT("sock->select_waiting > 0", sock->select_waiting > 0);
           if (sock->select_waiting > 0) {
             sock->select_waiting--;
@@ -1684,8 +1685,7 @@ again:
 }
 
 /**
- * Unimplemented: Close one end of a full-duplex connection.
+ * Close one end of a full-duplex connection.
- * Currently, the full connection is closed.
  */
 int
 lwip_shutdown(int s, int how)
@@ -1750,10 +1750,10 @@ lwip_getaddrname(int s, struct sockaddr *name, socklen_t *namelen, u8_t local)
   }
 
 #if LWIP_IPV4 && LWIP_IPV6
-  /* Dual-stack: Map IPv4 addresses to IPv6 mapped IPv4 */
+  /* Dual-stack: Map IPv4 addresses to IPv4 mapped IPv6 */
   if (NETCONNTYPE_ISIPV6(netconn_type(sock->conn)) &&
       IP_IS_V4_VAL(naddr)) {
-    ip4_2_ipv6_mapped_ipv4(ip_2_ip6(&naddr), ip_2_ip4(&naddr));
+    ip4_2_ipv4_mapped_ipv6(ip_2_ip6(&naddr), ip_2_ip4(&naddr));
     IP_SET_TYPE_VAL(naddr, IPADDR_TYPE_V6);
   }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
@@ -2574,6 +2574,12 @@ lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_
     switch (optname) {
 #if LWIP_IPV6 && LWIP_RAW
     case IPV6_CHECKSUM:
+      /* It should not be possible to disable the checksum generation with ICMPv6
+       * as per RFC 3542 chapter 3.1 */
+      if(sock->conn->pcb.raw->protocol == IPPROTO_ICMPV6) {
+        return EINVAL;
+      }
+
       LWIP_SOCKOPT_CHECK_OPTLEN_CONN_PCB_TYPE(sock, optlen, int, NETCONN_RAW);
       if (*(const int *)optval < 0) {
         sock->conn->pcb.raw->chksum_reqd = 0;

src/apps/httpd/lwip_httpd.c

@@ -102,7 +102,7 @@
 #include <stdlib.h> /* atoi */
 #include <stdio.h>
 
-#if LWIP_TCP
+#if LWIP_TCP && LWIP_CALLBACK_API
 
 /** Minimum length for a valid HTTP/0.9 request: "GET /\r\n" -> 7 bytes */
 #define MIN_REQ_LEN   7
@@ -335,9 +335,34 @@ char *http_cgi_param_vals[LWIP_HTTPD_MAX_CGI_PARAMETERS]; /* Values for each ext
 /** global list of active HTTP connections, use to kill the oldest when
     running out of memory */
 static struct http_state *http_connections;
-#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
 
-#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
+static void
+http_add_connection(struct http_state *hs)
+{
+  /* add the connection to the list */
+  hs->next = http_connections;
+  http_connections = hs;
+}
+
+static void
+http_remove_connection(struct http_state *hs)
+{
+  /* take the connection off the list */
+  if (http_connections) {
+    if (http_connections == hs) {
+      http_connections = hs->next;
+    } else {
+      struct http_state *last;
+      for(last = http_connections; last->next != NULL; last = last->next) {
+        if (last->next == hs) {
+          last->next = hs->next;
+          break;
+        }
+      }
+    }
+  }
+}
+
 static void
 http_kill_oldest_connection(u8_t ssi_required)
 {
@@ -366,6 +391,11 @@ http_kill_oldest_connection(u8_t ssi_required)
     http_close_or_abort_conn(hs_free_next->next->pcb, hs_free_next->next, 1); /* this also unlinks the http_state from the list */
   }
 }
+#else /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
+
+#define http_add_connection(hs)
+#define http_remove_connection(hs)
+
 #endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
 
 #if LWIP_HTTPD_SSI
@@ -422,17 +452,7 @@ http_state_alloc(void)
 #endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
   if (ret != NULL) {
     http_state_init(ret);
-#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
+    http_add_connection(ret);
-    /* add the connection to the list */
-    if (http_connections == NULL) {
-      http_connections = ret;
-    } else {
-      struct http_state *last;
-      for(last = http_connections; last->next != NULL; last = last->next);
-      LWIP_ASSERT("last != NULL", last != NULL);
-      last->next = ret;
-    }
-#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
   }
   return ret;
 }
@@ -481,22 +501,7 @@ http_state_free(struct http_state *hs)
 {
   if (hs != NULL) {
     http_state_eof(hs);
-#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
+    http_remove_connection(hs);
-    /* take the connection off the list */
-    if (http_connections) {
-      if (http_connections == hs) {
-        http_connections = hs->next;
-      } else {
-        struct http_state *last;
-        for(last = http_connections; last->next != NULL; last = last->next) {
-          if (last->next == hs) {
-            last->next = hs->next;
-            break;
-          }
-        }
-      }
-    }
-#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
     HTTP_FREE_HTTP_STATE(hs);
   }
 }
@@ -638,17 +643,14 @@ http_eof(struct tcp_pcb *pcb, struct http_state *hs)
   /* HTTP/1.1 persistent connection? (Not supported for SSI) */
 #if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
   if (hs->keepalive) {
-#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
+    http_remove_connection(hs);
-    struct http_state* next = hs->next;
+
-#endif
     http_state_eof(hs);
     http_state_init(hs);
     /* restore state: */
-#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
-    hs->next = next;
-#endif
     hs->pcb = pcb;
     hs->keepalive = 1;
+    http_add_connection(hs);
     /* ensure nagle doesn't interfere with sending all data as fast as possible: */
     tcp_nagle_disable(pcb);
   } else
@@ -1690,7 +1692,14 @@ http_post_rxpbuf(struct http_state *hs, struct pbuf *p)
       hs->post_content_len_left -= p->tot_len;
     }
   }
+#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
+  /* prevent connection being closed if httpd_post_data_recved() is called nested */
+  hs->unrecved_bytes++;
+#endif
   err = httpd_post_receive_data(hs, p);
+#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
+  hs->unrecved_bytes--;
+#endif
   if (err != ERR_OK) {
     /* Ignore remaining content in case of application error */
     hs->post_content_len_left = 0;
@@ -1751,8 +1760,8 @@ http_post_request(struct pbuf *inp, struct http_state *hs,
         if (content_len >= 0) {
           /* adjust length of HTTP header passed to application */
           const char *hdr_start_after_uri = uri_end + 1;
-          u16_t hdr_len = LWIP_MIN(data_len, crlfcrlf + 4 - data);
+          u16_t hdr_len = (u16_t)LWIP_MIN(data_len, crlfcrlf + 4 - data);
-          u16_t hdr_data_len = LWIP_MIN(data_len, crlfcrlf + 4 - hdr_start_after_uri);
+          u16_t hdr_data_len = (u16_t)LWIP_MIN(data_len, crlfcrlf + 4 - hdr_start_after_uri);
           u8_t post_auto_wnd = 1;
           http_uri_buf[0] = 0;
           /* trim http header */
@@ -2617,4 +2626,4 @@ http_set_cgi_handlers(const tCGI *cgis, int num_handlers)
 }
 #endif /* LWIP_HTTPD_CGI */
 
-#endif /* LWIP_TCP */
+#endif /* LWIP_TCP && LWIP_CALLBACK_API */

src/apps/lwiperf/lwip_lwiperf.c

@@ -53,7 +53,7 @@
 #include <string.h>
 
 /* Currently, only TCP-over-IPv4 is implemented (does iperf support IPv6 anyway?) */
-#if LWIP_IPV4 && LWIP_TCP
+#if LWIP_IPV4 && LWIP_TCP && LWIP_CALLBACK_API
 
 /** Specify the idle timeout (in seconds) after that the test fails */
 #ifndef LWIPERF_TCP_MAX_IDLE_SEC
@@ -658,4 +658,4 @@ lwiperf_abort(void* lwiperf_session)
   }
 }
 
-#endif /* LWIP_IPV4 && LWIP_TCP */
+#endif /* LWIP_IPV4 && LWIP_TCP && LWIP_CALLBACK_API */

src/apps/mqtt/lwip_mqtt.c

@@ -47,14 +47,16 @@
  * Erik Andersson <erian747@gmail.com>
  *
  */
-#include <string.h>
+#include "lwip/apps/mqtt.h"
 #include "lwip/timeouts.h"
 #include "lwip/ip_addr.h"
 #include "lwip/mem.h"
 #include "lwip/err.h"
 #include "lwip/pbuf.h"
 #include "lwip/tcp.h"
-#include "lwip/apps/mqtt.h"
+#include <string.h>
+
+#if LWIP_TCP && LWIP_CALLBACK_API
 
 /**
  * MQTT_DEBUG: Default is off.
@@ -257,7 +259,7 @@ mqtt_create_request(struct mqtt_request_t *r_objs, u16_t pkt_id, mqtt_request_cb
   struct mqtt_request_t *r = NULL;
   u8_t n;
   LWIP_ASSERT("mqtt_create_request: r_objs != NULL", r_objs != NULL);
-  for (n = 0; n < MQTT_REQ_MAX_IN_FLIGHT && r == NULL; n++) {
+  for (n = 0; n < MQTT_REQ_MAX_IN_FLIGHT; n++) {
     /* Item point to itself if not in use */
     if (r_objs[n].next == &r_objs[n]) {
       r = &r_objs[n];
@@ -265,6 +267,7 @@ mqtt_create_request(struct mqtt_request_t *r_objs, u16_t pkt_id, mqtt_request_cb
       r->cb = cb;
       r->arg = arg;
       r->pkt_id = pkt_id;
+      break;
     }
   }
   return r;
@@ -281,7 +284,7 @@ mqtt_append_request(struct mqtt_request_t **tail, struct mqtt_request_t *r)
 {
   struct mqtt_request_t *head = NULL;
   s16_t time_before = 0;
-  struct mqtt_request_t *iter = *tail;
+  struct mqtt_request_t *iter;
 
   LWIP_ASSERT("mqtt_append_request: tail != NULL", tail != NULL);
 
@@ -634,7 +637,7 @@ mqtt_incomming_suback(struct mqtt_request_t *r, u8_t result)
  * @param remaining_length Remaining length of complete message
  */
 static mqtt_connection_status_t
-mqtt_message_received(mqtt_client_t *client, u8_t fixed_hdr_idx, u16_t length, u32_t remaining_length)
+  mqtt_message_received(mqtt_client_t *client, u8_t fixed_hdr_idx, u16_t length, u32_t remaining_length)
 {
   mqtt_connection_status_t res = MQTT_CONNECT_ACCEPTED;
 
@@ -680,7 +683,7 @@ mqtt_message_received(mqtt_client_t *client, u8_t fixed_hdr_idx, u16_t length, u
       topic = var_hdr_payload + 2;
       after_topic = 2 + topic_len;
       /* Check length, add one byte even for QoS 0 so that zero termination will fit */
-      if ((after_topic + qos ? 2 : 1) > length) {
+      if ((after_topic + (qos? 2 : 1)) > length) {
         LWIP_DEBUGF(MQTT_DEBUG_WARN,("mqtt_message_received: Receive buffer can not fit topic + pkt_id\n"));
         goto out_disconnect;
       }
@@ -1230,6 +1233,7 @@ mqtt_client_connect(mqtt_client_t *client, const ip_addr_t *ip_addr, u16_t port,
     }
     len = strlen(client_info->will_topic);
     LWIP_ERROR("mqtt_client_connect: client_info->will_topic length overflow", len <= 0xFF, return ERR_VAL);
+    LWIP_ERROR("mqtt_client_connect: client_info->will_topic length must be > 0", len > 0, return ERR_VAL);
     will_topic_len = (u8_t)len;
     len = strlen(client_info->will_msg);
     LWIP_ERROR("mqtt_client_connect: client_info->will_msg length overflow", len <= 0xFF, return ERR_VAL);
@@ -1291,7 +1295,7 @@ mqtt_client_connect(mqtt_client_t *client, const ip_addr_t *ip_addr, u16_t port,
   /* Append client id */
   mqtt_output_append_string(&client->output, client_info->client_id, client_id_length);
   /* Append will message if used */
-  if (will_topic_len > 0) {
+  if ((flags & MQTT_CONNECT_FLAG_WILL) != 0) {
     mqtt_output_append_string(&client->output, client_info->will_topic, will_topic_len);
     mqtt_output_append_string(&client->output, client_info->will_msg, will_msg_len);
   }
@@ -1333,3 +1337,5 @@ mqtt_client_is_connected(mqtt_client_t *client)
   LWIP_ASSERT("mqtt_client_is_connected: client != NULL", client);
   return client->conn_state == MQTT_CONNECTED;
 }
+
+#endif /* LWIP_TCP && LWIP_CALLBACK_API */

src/core/ipv4/lwip_etharp.c

@@ -56,6 +56,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 #if LWIP_IPV4 && LWIP_ARP /* don't build if not configured for use in lwipopts.h */
 
 /** Re-request a used ARP entry 1 minute before it would expire to prevent
@@ -128,7 +132,11 @@ static u8_t etharp_cached_entry;
 
 
 static err_t etharp_request_dst(struct netif *netif, const ip4_addr_t *ipaddr, const struct eth_addr* hw_dst_addr);
-
+static err_t etharp_raw(struct netif *netif,
+                        const struct eth_addr *ethsrc_addr, const struct eth_addr *ethdst_addr,
+                        const struct eth_addr *hwsrc_addr, const ip4_addr_t *ipsrc_addr,
+                        const struct eth_addr *hwdst_addr, const ip4_addr_t *ipdst_addr,
+                        const u16_t opcode);
 
 #if ARP_QUEUEING
 /**
@@ -695,38 +703,12 @@ etharp_input(struct pbuf *p, struct netif *netif)
     LWIP_DEBUGF (ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: incoming ARP request\n"));
     /* ARP request for our address? */
     if (for_us) {
-
+      /* send ARP response */
-      LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("etharp_input: replying to ARP request for our IP address\n"));
+      etharp_raw(netif,
-      /* Re-use pbuf to send ARP reply.
+                 (struct eth_addr *)netif->hwaddr, &hdr->shwaddr,
-         Since we are re-using an existing pbuf, we can't call etharp_raw since
+                 (struct eth_addr *)netif->hwaddr, netif_ip4_addr(netif),
-         that would allocate a new pbuf. */
+                 &hdr->shwaddr, &sipaddr,
-      hdr->opcode = lwip_htons(ARP_REPLY);
+                 ARP_REPLY);
-
-      IPADDR2_COPY(&hdr->dipaddr, &hdr->sipaddr);
-      IPADDR2_COPY(&hdr->sipaddr, netif_ip4_addr(netif));
-
-      LWIP_ASSERT("netif->hwaddr_len must be the same as ETH_HWADDR_LEN for etharp!",
-                  (netif->hwaddr_len == ETH_HWADDR_LEN));
-
-      /* hwtype, hwaddr_len, proto, protolen and the type in the ethernet header
-         are already correct, we tested that before */
-
-      ETHADDR16_COPY(&hdr->dhwaddr, &hdr->shwaddr);
-      ETHADDR16_COPY(&hdr->shwaddr, netif->hwaddr);
-
-      /* return ARP reply */
-#if LWIP_AUTOIP
-      /* If we are using Link-Local, all ARP packets that contain a Link-Local
-       * 'sender IP address' MUST be sent using link-layer broadcast instead of
-       * link-layer unicast. (See RFC3927 Section 2.5, last paragraph) */
-      if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
-        ethernet_output(netif, p, &hdr->shwaddr, &ethbroadcast, ETHTYPE_ARP);
-      } else
-#endif /* LWIP_AUTOIP */
-      {
-        ethernet_output(netif, p, &hdr->shwaddr, &hdr->dhwaddr, ETHTYPE_ARP);
-      }
-
     /* we are not configured? */
     } else if (ip4_addr_isany_val(*netif_ip4_addr(netif))) {
       /* { for_us == 0 and netif->ip_addr.addr == 0 } */

src/core/ipv4/lwip_icmp.c

@@ -51,6 +51,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 /** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be
  * used to modify and send a response packet (and to 1 if this is not the case,
  * e.g. when link header is stripped of when receiving) */

src/core/ipv4/lwip_igmp.c

@@ -240,7 +240,7 @@ igmp_lookfor_group(struct netif *ifp, const ip4_addr_t *addr)
  * @return a struct igmp_group*,
  *         NULL on memory error.
  */
-struct igmp_group *
+static struct igmp_group *
 igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr)
 {
   struct igmp_group *group;

src/core/ipv4/lwip_ip4.c

@@ -59,6 +59,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 /** Set this to 0 in the rare case of wanting to call an extra function to
  * generate the IP checksum (in contrast to calculating it on-the-fly). */
 #ifndef LWIP_INLINE_IP_CHKSUM

src/core/ipv6/lwip_ip6.c

@@ -60,6 +60,10 @@
 #include "lwip/debug.h"
 #include "lwip/stats.h"
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 /**
  * Finds the appropriate network interface for a given IPv6 address. It tries to select
  * a netif following a sequence of heuristics:
@@ -443,9 +447,11 @@ ip6_input(struct pbuf *p, struct netif *inp)
   ip_addr_copy_from_ip6(ip_data.current_iphdr_dest, ip6hdr->dest);
   ip_addr_copy_from_ip6(ip_data.current_iphdr_src, ip6hdr->src);
 
-  /* Don't accept virtual IPv6 mapped IPv4 addresses */
+  /* Don't accept virtual IPv4 mapped IPv6 addresses.
-  if (ip6_addr_isipv6mappedipv4(ip_2_ip6(&ip_data.current_iphdr_dest)) ||
+   * Don't accept multicast source addresses. */
-     ip6_addr_isipv6mappedipv4(ip_2_ip6(&ip_data.current_iphdr_src))     ) {
+  if (ip6_addr_isipv4mappedipv6(ip_2_ip6(&ip_data.current_iphdr_dest)) ||
+     ip6_addr_isipv4mappedipv6(ip_2_ip6(&ip_data.current_iphdr_src)) ||
+     ip6_addr_ismulticast(ip_2_ip6(&ip_data.current_iphdr_src))) {
     IP6_STATS_INC(ip6.err);
     IP6_STATS_INC(ip6.drop);
     return ERR_OK;
@@ -815,8 +821,8 @@ ip6_output_if(struct pbuf *p, const ip6_addr_t *src, const ip6_addr_t *dest,
   const ip6_addr_t *src_used = src;
   if (dest != LWIP_IP_HDRINCL) {
     if (src != NULL && ip6_addr_isany(src)) {
-      src = ip_2_ip6(ip6_select_source_address(netif, dest));
+      src_used = ip_2_ip6(ip6_select_source_address(netif, dest));
-      if ((src == NULL) || ip6_addr_isany(src)) {
+      if ((src_used == NULL) || ip6_addr_isany(src_used)) {
         /* No appropriate source address was found for this packet. */
         LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_output: No suitable source address for packet.\n"));
         IP6_STATS_INC(ip6.rterr);

src/core/ipv6/lwip_mld6.c

@@ -573,6 +573,11 @@ mld6_send(struct netif *netif, struct mld_group *group, u8_t type)
   /* Add hop-by-hop headers options: router alert with MLD value. */
   ip6_options_add_hbh_ra(p, IP6_NEXTH_ICMP6, IP6_ROUTER_ALERT_VALUE_MLD);
 
+  if (type == ICMP6_TYPE_MLR) {
+    /* Remember we were the last to report */
+    group->last_reporter_flag = 1;
+  }
+
   /* Send the packet out. */
   MLD6_STATS_INC(mld6.xmit);
   ip6_output_if(p, (ip6_addr_isany(src_addr)) ? NULL : src_addr, &(group->group_address),

src/core/ipv6/lwip_nd6.c

@@ -64,6 +64,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 #if LWIP_IPV6_DUP_DETECT_ATTEMPTS > IP6_ADDR_TENTATIVE_COUNT_MASK
 #error LWIP_IPV6_DUP_DETECT_ATTEMPTS > IP6_ADDR_TENTATIVE_COUNT_MASK
 #endif

src/core/lwip_dns.c

@@ -280,6 +280,7 @@ DNS_LOCAL_HOSTLIST_STORAGE_PRE struct local_hostlist_entry local_hostlist_static
 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
 
 static void dns_init_local(void);
+static err_t dns_lookup_local(const char *hostname, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype));
 #endif /* DNS_LOCAL_HOSTLIST */
 
 
@@ -430,6 +431,38 @@ dns_init_local(void)
 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC && defined(DNS_LOCAL_HOSTLIST_INIT) */
 }
 
+/**
+ * @ingroup dns
+ * Iterate the local host-list for a hostname.
+ *
+ * @param iterator_fn a function that is called for every entry in the local host-list
+ * @param iterator_arg 3rd argument passed to iterator_fn
+ * @return the number of entries in the local host-list
+ */
+size_t
+dns_local_iterate(dns_found_callback iterator_fn, void *iterator_arg)
+{
+  size_t i;
+#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
+  struct local_hostlist_entry *entry = local_hostlist_dynamic;
+  i = 0;
+  while (entry != NULL) {
+    if (iterator_fn != NULL) {
+      iterator_fn(entry->name, &entry->addr, iterator_arg);
+    }
+    i++;
+    entry = entry->next;
+  }
+#else /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
+  for (i = 0; i < LWIP_ARRAYSIZE(local_hostlist_static); i++) {
+    if (iterator_fn != NULL) {
+      iterator_fn(local_hostlist_static[i].name, &local_hostlist_static[i].addr, iterator_arg);
+    }
+  }
+#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
+  return i;
+}
+
 /**
  * @ingroup dns
  * Scans the local host-list for a hostname.
@@ -437,8 +470,20 @@ dns_init_local(void)
  * @param hostname Hostname to look for in the local host-list
  * @param addr the first IP address for the hostname in the local host-list or
  *         IPADDR_NONE if not found.
+ * @param dns_addrtype - LWIP_DNS_ADDRTYPE_IPV4_IPV6: try to resolve IPv4 (ATTENTION: no fallback here!)
+ *                     - LWIP_DNS_ADDRTYPE_IPV6_IPV4: try to resolve IPv6 (ATTENTION: no fallback here!)
+ *                     - LWIP_DNS_ADDRTYPE_IPV4: try to resolve IPv4 only
+ *                     - LWIP_DNS_ADDRTYPE_IPV6: try to resolve IPv6 only
  * @return ERR_OK if found, ERR_ARG if not found
  */
+err_t
+dns_local_lookup(const char *hostname, ip_addr_t *addr, u8_t dns_addrtype)
+{
+  LWIP_UNUSED_ARG(dns_addrtype);
+  return dns_lookup_local(hostname, addr LWIP_DNS_ADDRTYPE_ARG(dns_addrtype));
+}
+
+/* Internal implementation for dns_local_lookup and dns_lookup */
 static err_t
 dns_lookup_local(const char *hostname, ip_addr_t *addr LWIP_DNS_ADDRTYPE_ARG(u8_t dns_addrtype))
 {
@@ -1436,9 +1481,9 @@ dns_gethostbyname(const char *hostname, ip_addr_t *addr, dns_found_callback foun
  *              ERR_INPROGRESS is returned!)
  * @param callback_arg argument to pass to the callback function
  * @param dns_addrtype - LWIP_DNS_ADDRTYPE_IPV4_IPV6: try to resolve IPv4 first, try IPv6 if IPv4 fails only
- *                      - LWIP_DNS_ADDRTYPE_IPV6_IPV4: try to resolve IPv6 first, try IPv4 if IPv6 fails only
+ *                     - LWIP_DNS_ADDRTYPE_IPV6_IPV4: try to resolve IPv6 first, try IPv4 if IPv6 fails only
- *                      - LWIP_DNS_ADDRTYPE_IPV4: try to resolve IPv4 only
+ *                     - LWIP_DNS_ADDRTYPE_IPV4: try to resolve IPv4 only
- *                      - LWIP_DNS_ADDRTYPE_IPV6: try to resolve IPv6 only
+ *                     - LWIP_DNS_ADDRTYPE_IPV6: try to resolve IPv6 only
  */
 err_t
 dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *addr, dns_found_callback found,

src/core/lwip_init.c

@@ -218,9 +218,6 @@ PACK_STRUCT_END
 #if !LWIP_ETHERNET && (LWIP_ARP || PPPOE_SUPPORT)
   #error "LWIP_ETHERNET needs to be turned on for LWIP_ARP or PPPOE_SUPPORT"
 #endif
-#if (LWIP_IGMP || LWIP_IPV6) && !defined(LWIP_RAND)
-  #error "When using IGMP or IPv6, LWIP_RAND() needs to be defined to a random-function returning an u32_t random value (in arch/cc.h)"
-#endif
 #if LWIP_TCPIP_CORE_LOCKING_INPUT && !LWIP_TCPIP_CORE_LOCKING
   #error "When using LWIP_TCPIP_CORE_LOCKING_INPUT, LWIP_TCPIP_CORE_LOCKING must be enabled, too"
 #endif

src/core/lwip_memp.c

@@ -75,7 +75,6 @@
 #include "lwip/ip6_frag.h"
 #include "lwip/mld6.h"
 
-
 #define LWIP_MEMPOOL(name,num,size,desc) LWIP_MEMPOOL_DECLARE(name,num,size,desc)
 #include "lwip/priv/memp_std.h"
 
@@ -84,6 +83,10 @@ const struct memp_desc* const memp_pools[MEMP_MAX] = {
 #include "lwip/priv/memp_std.h"
 };
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 #if MEMP_MEM_MALLOC && MEMP_OVERFLOW_CHECK >= 2
 #undef MEMP_OVERFLOW_CHECK
 /* MEMP_OVERFLOW_CHECK >= 2 does not work with MEMP_MEM_MALLOC, use 1 instead */

src/core/lwip_pbuf.c

@@ -350,8 +350,18 @@ pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
 
     break;
   case PBUF_RAM:
-    /* If pbuf is to be allocated in RAM, allocate memory for it. */
+    {
-    p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
+      mem_size_t alloc_len = LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length);
+      
+      /* bug #50040: Check for integer overflow when calculating alloc_len */
+      if (alloc_len < LWIP_MEM_ALIGN_SIZE(length)) {
+        return NULL;
+      }
+    
+      /* If pbuf is to be allocated in RAM, allocate memory for it. */
+      p = (struct pbuf*)mem_malloc(alloc_len);
+    }
+
     if (p == NULL) {
       return NULL;
     }
@@ -812,6 +822,7 @@ pbuf_ref(struct pbuf *p)
   /* pbuf given? */
   if (p != NULL) {
     SYS_ARCH_INC(p->ref, 1);
+    LWIP_ASSERT("pbuf ref overflow", p->ref > 0);
   }
 }
 

src/core/lwip_raw.c

@@ -209,7 +209,7 @@ raw_input(struct pbuf *p, struct netif *inp)
 err_t
 raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
 {
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
   ip_addr_set_ipaddr(&pcb->local_ip, ipaddr);
@@ -233,7 +233,7 @@ raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
 err_t
 raw_connect(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
 {
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
   ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr);

src/core/lwip_stats.c

@@ -96,7 +96,7 @@ stats_display_igmp(struct stats_igmp *igmp, const char *name)
   LWIP_PLATFORM_DIAG(("rx_report: %"STAT_COUNTER_F"\n\t", igmp->rx_report));
   LWIP_PLATFORM_DIAG(("tx_join: %"STAT_COUNTER_F"\n\t", igmp->tx_join));
   LWIP_PLATFORM_DIAG(("tx_leave: %"STAT_COUNTER_F"\n\t", igmp->tx_leave));
-  LWIP_PLATFORM_DIAG(("tx_report: %"STAT_COUNTER_F"\n\t", igmp->tx_report));
+  LWIP_PLATFORM_DIAG(("tx_report: %"STAT_COUNTER_F"\n", igmp->tx_report));
 }
 #endif /* IGMP_STATS || MLD6_STATS */
 
@@ -135,7 +135,7 @@ stats_display_sys(struct stats_sys *sys)
   LWIP_PLATFORM_DIAG(("mutex.err:  %"U32_F"\n\t", (u32_t)sys->mutex.err));
   LWIP_PLATFORM_DIAG(("mbox.used:  %"U32_F"\n\t", (u32_t)sys->mbox.used));
   LWIP_PLATFORM_DIAG(("mbox.max:   %"U32_F"\n\t", (u32_t)sys->mbox.max));
-  LWIP_PLATFORM_DIAG(("mbox.err:   %"U32_F"\n\t", (u32_t)sys->mbox.err));
+  LWIP_PLATFORM_DIAG(("mbox.err:   %"U32_F"\n", (u32_t)sys->mbox.err));
 }
 #endif /* SYS_STATS */
 

src/core/lwip_tcp.c

@@ -62,6 +62,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 #ifndef TCP_LOCAL_PORT_RANGE_START
 /* From http://www.iana.org/assignments/port-numbers:
    "The Dynamic and/or Private Ports are those from 49152 through 65535" */
@@ -132,6 +136,8 @@ static u8_t tcp_timer;
 static u8_t tcp_timer_ctr;
 static u16_t tcp_new_port(void);
 
+static err_t tcp_close_shutdown_fin(struct tcp_pcb *pcb);
+
 /**
  * Initialize this module.
  */
@@ -258,8 +264,6 @@ tcp_backlog_accepted(struct tcp_pcb* pcb)
 static err_t
 tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
 {
-  err_t err;
-
   if (rst_on_unacked_data && ((pcb->state == ESTABLISHED) || (pcb->state == CLOSE_WAIT))) {
     if ((pcb->refused_data != NULL) || (pcb->rcv_wnd != TCP_WND_MAX(pcb))) {
       /* Not all data received by application, send RST to tell the remote
@@ -290,6 +294,8 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
     }
   }
 
+  /* - states which free the pcb are handled here,
+     - states which send FIN and change state are handled in tcp_close_shutdown_fin() */
   switch (pcb->state) {
   case CLOSED:
     /* Closing a pcb in the CLOSED state might seem erroneous,
@@ -299,27 +305,34 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
      * or for a pcb that has been used and then entered the CLOSED state
      * is erroneous, but this should never happen as the pcb has in those cases
      * been freed, and so any remaining handles are bogus. */
-    err = ERR_OK;
     if (pcb->local_port != 0) {
       TCP_RMV(&tcp_bound_pcbs, pcb);
     }
     memp_free(MEMP_TCP_PCB, pcb);
-    pcb = NULL;
     break;
   case LISTEN:
-    err = ERR_OK;
     tcp_listen_closed(pcb);
     tcp_pcb_remove(&tcp_listen_pcbs.pcbs, pcb);
     memp_free(MEMP_TCP_PCB_LISTEN, pcb);
-    pcb = NULL;
     break;
   case SYN_SENT:
-    err = ERR_OK;
     TCP_PCB_REMOVE_ACTIVE(pcb);
     memp_free(MEMP_TCP_PCB, pcb);
-    pcb = NULL;
     MIB2_STATS_INC(mib2.tcpattemptfails);
     break;
+  default:
+    return tcp_close_shutdown_fin(pcb);
+  }
+  return ERR_OK;
+}
+
+static err_t
+tcp_close_shutdown_fin(struct tcp_pcb *pcb)
+{
+  err_t err;
+  LWIP_ASSERT("pcb != NULL", pcb != NULL);
+
+  switch (pcb->state) {
   case SYN_RCVD:
     err = tcp_send_fin(pcb);
     if (err == ERR_OK) {
@@ -344,18 +357,20 @@ tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
     break;
   default:
     /* Has already been closed, do nothing. */
-    err = ERR_OK;
+    return ERR_OK;
-    pcb = NULL;
     break;
   }
 
-  if (pcb != NULL && err == ERR_OK) {
+  if (err == ERR_OK) {
     /* To ensure all data has been sent when tcp_close returns, we have
        to make sure tcp_output doesn't fail.
        Since we don't really have to ensure all data has been sent when tcp_close
        returns (unsent data is sent from tcp timer functions, also), we don't care
        for the return value of tcp_output for now. */
     tcp_output(pcb);
+  } else if (err == ERR_MEM) {
+    /* Mark this pcb for closing. Closing is retried from tcp_tmr. */
+    pcb->flags |= TF_CLOSEPEND;
   }
   return err;
 }
@@ -467,6 +482,7 @@ tcp_abandon(struct tcp_pcb *pcb, int reset)
   } else {
     int send_rst = 0;
     u16_t local_port = 0;
+    enum tcp_state last_state;
     seqno = pcb->snd_nxt;
     ackno = pcb->rcv_nxt;
 #if LWIP_CALLBACK_API
@@ -499,8 +515,9 @@ tcp_abandon(struct tcp_pcb *pcb, int reset)
       LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
       tcp_rst(seqno, ackno, &pcb->local_ip, &pcb->remote_ip, local_port, pcb->remote_port);
     }
+    last_state = pcb->state;
     memp_free(MEMP_TCP_PCB, pcb);
-    TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
+    TCP_EVENT_ERR(last_state, errf, errf_arg, ERR_ABRT);
   }
 }
 
@@ -551,7 +568,7 @@ tcp_bind(struct tcp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
 #endif /* LWIP_IPV4 */
 
   /* still need to check for ipaddr == NULL in IPv6 only case */
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
 
@@ -859,7 +876,7 @@ tcp_connect(struct tcp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port,
   u32_t iss;
   u16_t old_local_port;
 
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
 
@@ -931,7 +948,6 @@ tcp_connect(struct tcp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port,
   pcb->mss = tcp_eff_send_mss(pcb->mss, &pcb->local_ip, &pcb->remote_ip);
 #endif /* TCP_CALCULATE_EFF_SEND_MSS */
   pcb->cwnd = 1;
-  pcb->ssthresh = TCP_WND;
 #if LWIP_CALLBACK_API
   pcb->connected = connected;
 #else /* LWIP_CALLBACK_API */
@@ -997,11 +1013,11 @@ tcp_slowtmr_start:
     pcb_remove = 0;
     pcb_reset = 0;
 
-    if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
+    if (pcb->state == SYN_SENT && pcb->nrtx >= TCP_SYNMAXRTX) {
       ++pcb_remove;
       LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
     }
-    else if (pcb->nrtx == TCP_MAXRTX) {
+    else if (pcb->nrtx >= TCP_MAXRTX) {
       ++pcb_remove;
       LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
     } else {
@@ -1035,7 +1051,8 @@ tcp_slowtmr_start:
           /* Double retransmission time-out unless we are trying to
            * connect to somebody (i.e., we are in SYN_SENT). */
           if (pcb->state != SYN_SENT) {
-            pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
+            u8_t backoff_idx = LWIP_MIN(pcb->nrtx, sizeof(tcp_backoff)-1);
+            pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[backoff_idx];
           }
 
           /* Reset the retransmission timer. */
@@ -1132,6 +1149,7 @@ tcp_slowtmr_start:
       tcp_err_fn err_fn = pcb->errf;
 #endif /* LWIP_CALLBACK_API */
       void *err_arg;
+      enum tcp_state last_state;
       tcp_pcb_purge(pcb);
       /* Remove PCB from tcp_active_pcbs list. */
       if (prev != NULL) {
@@ -1149,12 +1167,13 @@ tcp_slowtmr_start:
       }
 
       err_arg = pcb->callback_arg;
+      last_state = pcb->state;
       pcb2 = pcb;
       pcb = pcb->next;
       memp_free(MEMP_TCP_PCB, pcb2);
 
       tcp_active_pcbs_changed = 0;
-      TCP_EVENT_ERR(err_fn, err_arg, ERR_ABRT);
+      TCP_EVENT_ERR(last_state, err_fn, err_arg, ERR_ABRT);
       if (tcp_active_pcbs_changed) {
         goto tcp_slowtmr_start;
       }
@@ -1244,6 +1263,12 @@ tcp_fasttmr_start:
         tcp_output(pcb);
         pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
       }
+      /* send pending FIN */
+      if (pcb->flags & TF_CLOSEPEND) {
+        LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: pending FIN\n"));
+        pcb->flags &= ~(TF_CLOSEPEND);
+        tcp_close_shutdown_fin(pcb);
+      }
 
       next = pcb->next;
 
@@ -1590,6 +1615,14 @@ tcp_alloc(u8_t prio)
     pcb->tmr = tcp_ticks;
     pcb->last_timer = tcp_timer_ctr;
 
+    /* RFC 5681 recommends setting ssthresh abritrarily high and gives an example
+    of using the largest advertised receive window.  We've seen complications with
+    receiving TCPs that use window scaling and/or window auto-tuning where the
+    initial advertised window is very small and then grows rapidly once the
+    connection is established. To avoid these complications, we set ssthresh to the
+    largest effective cwnd (amount of in-flight data) that the sender can have. */
+    pcb->ssthresh = TCP_SND_BUF;
+
 #if LWIP_CALLBACK_API
     pcb->recv = tcp_recv_null;
 #endif /* LWIP_CALLBACK_API */

src/core/lwip_tcp_in.c

@@ -61,8 +61,6 @@
 
 /** Initial CWND calculation as defined RFC 2581 */
 #define LWIP_TCP_CALC_INITIAL_CWND(mss) LWIP_MIN((4U * (mss)), LWIP_MAX((2U * (mss)), 4380U));
-/** Initial slow start threshold value: we use the full window */
-#define LWIP_TCP_INITIAL_SSTHRESH(pcb)  ((pcb)->snd_wnd)
 
 /* These variables are global to all functions involved in the input
    processing of TCP segments. They are set by the tcp_input()
@@ -378,7 +376,7 @@ tcp_input(struct pbuf *p, struct netif *inp)
            end. We then call the error callback to inform the
            application that the connection is dead before we
            deallocate the PCB. */
-        TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST);
+        TCP_EVENT_ERR(pcb->state, pcb->errf, pcb->callback_arg, ERR_RST);
         tcp_pcb_remove(&tcp_active_pcbs, pcb);
         memp_free(MEMP_TCP_PCB, pcb);
       } else {
@@ -413,7 +411,7 @@ tcp_input(struct pbuf *p, struct netif *inp)
             /* Connection closed although the application has only shut down the
                tx side: call the PCB's err callback and indicate the closure to
                ensure the application doesn't continue using the PCB. */
-            TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_CLSD);
+            TCP_EVENT_ERR(pcb->state, pcb->errf, pcb->callback_arg, ERR_CLSD);
           }
           tcp_pcb_remove(&tcp_active_pcbs, pcb);
           memp_free(MEMP_TCP_PCB, pcb);
@@ -615,7 +613,6 @@ tcp_listen_input(struct tcp_pcb_listen *pcb)
     tcp_parseopt(npcb);
     npcb->snd_wnd = tcphdr->wnd;
     npcb->snd_wnd_max = npcb->snd_wnd;
-    npcb->ssthresh = LWIP_TCP_INITIAL_SSTHRESH(npcb);
 
 #if TCP_CALCULATE_EFF_SEND_MSS
     npcb->mss = tcp_eff_send_mss(npcb->mss, &npcb->local_ip, &npcb->remote_ip);
@@ -771,9 +768,6 @@ tcp_process(struct tcp_pcb *pcb)
       pcb->mss = tcp_eff_send_mss(pcb->mss, &pcb->local_ip, &pcb->remote_ip);
 #endif /* TCP_CALCULATE_EFF_SEND_MSS */
 
-      /* Set ssthresh again after changing 'mss' and 'snd_wnd' */
-      pcb->ssthresh = LWIP_TCP_INITIAL_SSTHRESH(pcb);
-
       pcb->cwnd = LWIP_TCP_CALC_INITIAL_CWND(pcb->mss);
       LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_process (SENT): cwnd %"TCPWNDSIZE_F
                                    " ssthresh %"TCPWNDSIZE_F"\n",
@@ -816,9 +810,12 @@ tcp_process(struct tcp_pcb *pcb)
       tcp_rst(ackno, seqno + tcplen, ip_current_dest_addr(),
         ip_current_src_addr(), tcphdr->dest, tcphdr->src);
       /* Resend SYN immediately (don't wait for rto timeout) to establish
-        connection faster */
+        connection faster, but do not send more SYNs than we otherwise would
-      pcb->rtime = 0;
+        have, or we might get caught in a loop on loopback interfaces. */
-      tcp_rexmit_rto(pcb);
+      if (pcb->nrtx < TCP_SYNMAXRTX) {
+        pcb->rtime = 0;
+        tcp_rexmit_rto(pcb);
+      }
     }
     break;
   case SYN_RCVD:
@@ -827,14 +824,16 @@ tcp_process(struct tcp_pcb *pcb)
       if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) {
         pcb->state = ESTABLISHED;
         LWIP_DEBUGF(TCP_DEBUG, ("TCP connection established %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
+#if LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG
 #if LWIP_CALLBACK_API
         LWIP_ASSERT("pcb->listener->accept != NULL",
           (pcb->listener == NULL) || (pcb->listener->accept != NULL));
+#endif
         if (pcb->listener == NULL) {
           /* listen pcb might be closed by now */
           err = ERR_VAL;
         } else
-#endif
+#endif /* LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG */
         {
           tcp_backlog_accepted(pcb);
           /* Call the accept function. */
@@ -853,11 +852,6 @@ tcp_process(struct tcp_pcb *pcb)
          * we'd better pass it on to the application as well. */
         tcp_receive(pcb);
 
-        /* passive open: update initial ssthresh now that the correct window is
-           known: if the remote side supports window scaling, the window sent
-           with the initial SYN can be smaller than the one used later */
-        pcb->ssthresh = LWIP_TCP_INITIAL_SSTHRESH(pcb);
-
         /* Prevent ACK for SYN to generate a sent event */
         if (recv_acked != 0) {
           recv_acked--;
@@ -925,7 +919,7 @@ tcp_process(struct tcp_pcb *pcb)
     break;
   case CLOSING:
     tcp_receive(pcb);
-    if (flags & TCP_ACK && ackno == pcb->snd_nxt && pcb->unsent == NULL) {
+    if ((flags & TCP_ACK) && ackno == pcb->snd_nxt && pcb->unsent == NULL) {
       LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: CLOSING %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
       tcp_pcb_purge(pcb);
       TCP_RMV_ACTIVE(pcb);
@@ -935,7 +929,7 @@ tcp_process(struct tcp_pcb *pcb)
     break;
   case LAST_ACK:
     tcp_receive(pcb);
-    if (flags & TCP_ACK && ackno == pcb->snd_nxt && pcb->unsent == NULL) {
+    if ((flags & TCP_ACK) && ackno == pcb->snd_nxt && pcb->unsent == NULL) {
       LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: LAST_ACK %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
       /* bugfix #21699: don't set pcb->state to CLOSED here or we risk leaking segments */
       recv_flags |= TF_CLOSED;
@@ -1417,7 +1411,7 @@ tcp_receive(struct tcp_pcb *pcb)
                    TCP_SEQ_GEQ(seqno + tcplen,
                                next->tcphdr->seqno + next->len)) {
               /* inseg cannot have FIN here (already processed above) */
-              if (TCPH_FLAGS(next->tcphdr) & TCP_FIN &&
+              if ((TCPH_FLAGS(next->tcphdr) & TCP_FIN) != 0 &&
                   (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) == 0) {
                 TCPH_SET_FLAG(inseg.tcphdr, TCP_FIN);
                 tcplen = TCP_TCPLEN(&inseg);

src/core/lwip_tcp_out.c

@@ -376,6 +376,9 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
 #if TCP_OVERSIZE
   u16_t oversize = 0;
   u16_t oversize_used = 0;
+#if TCP_OVERSIZE_DBGCHECK
+  u16_t oversize_add = 0;
+#endif /* TCP_OVERSIZE_DBGCHECK*/
 #endif /* TCP_OVERSIZE */
   u16_t extendlen = 0;
 #if TCP_CHECKSUM_ON_COPY
@@ -461,13 +464,13 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
      */
 #if TCP_OVERSIZE
 #if TCP_OVERSIZE_DBGCHECK
-    /* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
+    /* check that pcb->unsent_oversize matches last_unsent->oversize_left */
     LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
                 pcb->unsent_oversize == last_unsent->oversize_left);
 #endif /* TCP_OVERSIZE_DBGCHECK */
     oversize = pcb->unsent_oversize;
     if (oversize > 0) {
-      LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
+      LWIP_ASSERT("inconsistent oversize vs. space", oversize <= space);
       seg = last_unsent;
       oversize_used = LWIP_MIN(space, LWIP_MIN(oversize, len));
       pos += oversize_used;
@@ -475,7 +478,7 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
       space -= oversize_used;
     }
     /* now we are either finished or oversize is zero */
-    LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len));
+    LWIP_ASSERT("inconsistent oversize vs. len", (oversize == 0) || (pos == len));
 #endif /* TCP_OVERSIZE */
 
     /*
@@ -490,7 +493,7 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
      * the end.
      */
     if ((pos < len) && (space > 0) && (last_unsent->len > 0)) {
-      u16_t seglen = space < len - pos ? space : len - pos;
+      u16_t seglen = LWIP_MIN(space, len - pos);
       seg = last_unsent;
 
       /* Create a pbuf with a copy or reference to seglen bytes. We
@@ -505,7 +508,7 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
           goto memerr;
         }
 #if TCP_OVERSIZE_DBGCHECK
-        last_unsent->oversize_left += oversize;
+        oversize_add = oversize;
 #endif /* TCP_OVERSIZE_DBGCHECK */
         TCP_DATA_COPY2(concat_p->payload, (const u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
 #if TCP_CHECKSUM_ON_COPY
@@ -557,7 +560,7 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
     struct pbuf *p;
     u16_t left = len - pos;
     u16_t max_len = mss_local - optlen;
-    u16_t seglen = left > max_len ? max_len : left;
+    u16_t seglen = LWIP_MIN(left, max_len);
 #if TCP_CHECKSUM_ON_COPY
     u16_t chksum = 0;
     u8_t chksum_swapped = 0;
@@ -656,6 +659,11 @@ tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
    * All three segmentation phases were successful. We can commit the
    * transaction.
    */
+#if TCP_OVERSIZE_DBGCHECK
+  if ((last_unsent != NULL) && (oversize_add != 0)) {
+    last_unsent->oversize_left += oversize_add;
+  }
+#endif /* TCP_OVERSIZE_DBGCHECK */
 
   /*
    * Phase 1: If data has been added to the preallocated tail of
@@ -1412,7 +1420,9 @@ tcp_rexmit_rto(struct tcp_pcb *pcb)
   pcb->unacked = NULL;
 
   /* increment number of retransmissions */
-  ++pcb->nrtx;
+  if (pcb->nrtx < 0xFF) {
+    ++pcb->nrtx;
+  }
 
   /* Don't take any RTT measurements after retransmitting. */
   pcb->rttest = 0;
@@ -1457,7 +1467,9 @@ tcp_rexmit(struct tcp_pcb *pcb)
   }
 #endif /* TCP_OVERSIZE */
 
-  ++pcb->nrtx;
+  if (pcb->nrtx < 0xFF) {
+    ++pcb->nrtx;
+  }
 
   /* Don't take any rtt measurements after retransmitting. */
   pcb->rttest = 0;
@@ -1488,11 +1500,7 @@ tcp_rexmit_fast(struct tcp_pcb *pcb)
 
     /* Set ssthresh to half of the minimum of the current
      * cwnd and the advertised window */
-    if (pcb->cwnd > pcb->snd_wnd) {
+    pcb->ssthresh = LWIP_MIN(pcb->cwnd, pcb->snd_wnd) / 2;
-      pcb->ssthresh = pcb->snd_wnd / 2;
-    } else {
-      pcb->ssthresh = pcb->cwnd / 2;
-    }
 
     /* The minimum value for ssthresh should be 2 MSS */
     if (pcb->ssthresh < (2U * pcb->mss)) {

src/core/lwip_udp.c

@@ -892,7 +892,7 @@ udp_bind(struct udp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
 #endif /* LWIP_IPV4 */
 
   /* still need to check for ipaddr == NULL in IPv6 only case */
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
 
@@ -982,7 +982,7 @@ udp_connect(struct udp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
 {
   struct udp_pcb *ipcb;
 
-  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+  if ((pcb == NULL) || (ipaddr == NULL)) {
     return ERR_VAL;
   }
 

src/include/lwip/apps/mqtt.h

@@ -39,8 +39,9 @@
 
 #include "lwip/apps/mqtt_opts.h"
 #include "lwip/err.h"
+#include "lwip/ip_addr.h"
 
-#ifdef	__cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -236,7 +237,7 @@ err_t mqtt_sub_unsub(mqtt_client_t *client, const char *topic, u8_t qos, mqtt_re
 err_t mqtt_publish(mqtt_client_t *client, const char *topic, const void *payload, u16_t payload_length, u8_t qos, u8_t retain,
                                     mqtt_request_cb_t cb, void *arg);
 
-#ifdef	__cplusplus
+#ifdef __cplusplus
 }
 #endif
 

src/include/lwip/arch.h

@@ -66,7 +66,7 @@
 #endif
 
 /** Define random number generator function of your system */
-#ifndef LWIP_RAND
+#ifdef __DOXYGEN__
 #define LWIP_RAND() ((u32_t)rand())
 #endif
 
@@ -76,7 +76,7 @@
  * systems, this should be defined to something less resource-consuming.
  */
 #ifndef LWIP_PLATFORM_DIAG
-#define LWIP_PLATFORM_DIAG(x)	do {printf x;} while(0)
+#define LWIP_PLATFORM_DIAG(x) do {printf x;} while(0)
 #include <stdio.h>
 #include <stdlib.h>
 #endif
@@ -162,6 +162,19 @@ typedef uintptr_t mem_ptr_t;
 #endif
 #endif
 
+/** Define this to 1 in arch/cc.h of your port if your compiler does not provide
+ * the limits.h header. You need to define the type limits yourself in this case
+ * (e.g. INT_MAX).
+ */
+#ifndef LWIP_NO_LIMITS_H
+#define LWIP_NO_LIMITS_H 0
+#endif
+
+/* Include limits.h? */
+#if !LWIP_NO_LIMITS_H
+#include <limits.h>
+#endif
+
 /** C++ const_cast<target_type>(val) equivalent to remove constness from a value (GCC -Wcast-qual) */
 #ifndef LWIP_CONST_CAST
 #define LWIP_CONST_CAST(target_type, val) ((target_type)((ptrdiff_t)val))

src/include/lwip/dns.h

@@ -76,6 +76,7 @@ struct local_hostlist_entry {
   ip_addr_t addr;
   struct local_hostlist_entry *next;
 };
+#define DNS_LOCAL_HOSTLIST_ELEM(name, addr_init) {name, addr_init, NULL}
 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
 #ifndef DNS_LOCAL_HOSTLIST_MAX_NAMELEN
 #define DNS_LOCAL_HOSTLIST_MAX_NAMELEN  DNS_MAX_NAME_LENGTH
@@ -111,10 +112,14 @@ err_t            dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *add
                                    u8_t dns_addrtype);
 
 
-#if DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC
+#if DNS_LOCAL_HOSTLIST
+size_t         dns_local_iterate(dns_found_callback iterator_fn, void *iterator_arg);
+err_t          dns_local_lookup(const char *hostname, ip_addr_t *addr, u8_t dns_addrtype);
+#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
 int            dns_local_removehost(const char *hostname, const ip_addr_t *addr);
 err_t          dns_local_addhost(const char *hostname, const ip_addr_t *addr);
-#endif /* DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
+#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
+#endif /* DNS_LOCAL_HOSTLIST */
 
 #ifdef __cplusplus
 }

src/include/lwip/icmp.h

@@ -69,7 +69,7 @@ enum icmp_dur_type {
 
 /** ICMP time exceeded codes */
 enum icmp_te_type {
-  /* time to live exceeded in transit */
+  /** time to live exceeded in transit */
   ICMP_TE_TTL  = 0,
   /** fragment reassembly time exceeded */
   ICMP_TE_FRAG = 1

src/include/lwip/init.h

@@ -54,7 +54,7 @@ extern "C" {
 /** x.X.x: Minor version of the stack */
 #define LWIP_VERSION_MINOR      0
 /** x.x.X: Revision of the stack */
-#define LWIP_VERSION_REVISION   1
+#define LWIP_VERSION_REVISION   2
 /** For release candidates, this is set to 1..254
   * For official releases, this is set to 255 (LWIP_RC_RELEASE)
   * For development versions (Git), this is set to 0 (LWIP_RC_DEVELOPMENT) */

src/include/lwip/ip6_addr.h

@@ -159,7 +159,7 @@ typedef struct ip6_addr ip6_addr_t;
 
 #define ip6_addr_isuniquelocal(ip6addr) (((ip6addr)->addr[0] & PP_HTONL(0xfe000000UL)) == PP_HTONL(0xfc000000UL))
 
-#define ip6_addr_isipv6mappedipv4(ip6addr) (((ip6addr)->addr[0] == 0) && ((ip6addr)->addr[1] == 0) && (((ip6addr)->addr[2]) == PP_HTONL(0x0000FFFFUL)))
+#define ip6_addr_isipv4mappedipv6(ip6addr) (((ip6addr)->addr[0] == 0) && ((ip6addr)->addr[1] == 0) && (((ip6addr)->addr[2]) == PP_HTONL(0x0000FFFFUL)))
 
 #define ip6_addr_ismulticast(ip6addr) (((ip6addr)->addr[0] & PP_HTONL(0xff000000UL)) == PP_HTONL(0xff000000UL))
 #define ip6_addr_multicast_transient_flag(ip6addr)  ((ip6addr)->addr[0] & PP_HTONL(0x00100000UL))

src/include/lwip/ip_addr.h

@@ -222,14 +222,14 @@ int ipaddr_aton(const char *cp, ip_addr_t *addr);
 #define IPADDR_STRLEN_MAX   IP6ADDR_STRLEN_MAX
 
 /** @ingroup ipaddr */
-#define ip4_2_ipv6_mapped_ipv4(ip6addr, ip4addr) do { \
+#define ip4_2_ipv4_mapped_ipv6(ip6addr, ip4addr) do { \
   (ip6addr)->addr[3] = (ip4addr)->addr; \
   (ip6addr)->addr[2] = PP_HTONL(0x0000FFFFUL); \
   (ip6addr)->addr[1] = 0; \
   (ip6addr)->addr[0] = 0; } while(0);
 
 /** @ingroup ipaddr */
-#define unmap_ipv6_mapped_ipv4(ip4addr, ip6addr) \
+#define unmap_ipv4_mapped_ipv6(ip4addr, ip6addr) \
   (ip4addr)->addr = (ip6addr)->addr[3];
 
 #define IP46_ADDR_ANY(type) (((type) == IPADDR_TYPE_V6)? IP6_ADDR_ANY : IP4_ADDR_ANY)

src/include/lwip/opt.h

@@ -1047,11 +1047,9 @@
 #define LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING 2
 #define LWIP_DNS_SECURE_RAND_SRC_PORT           4
 
-/** DNS_LOCAL_HOSTLIST: Implements a local host-to-address list. If enabled,
+/** DNS_LOCAL_HOSTLIST: Implements a local host-to-address list. If enabled, you have to define an initializer:
- *  you have to define
+ *  \#define DNS_LOCAL_HOSTLIST_INIT {DNS_LOCAL_HOSTLIST_ELEM("host_ip4", IPADDR4_INIT_BYTES(1,2,3,4)), \
- *  \#define DNS_LOCAL_HOSTLIST_INIT {{"host1", 0x123}, {"host2", 0x234}}
+ *                                    DNS_LOCAL_HOSTLIST_ELEM("host_ip6", IPADDR6_INIT_HOST(123, 234, 345, 456)}
- *  (an array of structs name/address, where address is an u32_t in network
- *  byte order).
  *
  *  Instead, you can also use an external function:
  *  \#define DNS_LOOKUP_LOCAL_EXTERN(x) extern err_t my_lookup_function(const char *name, ip_addr_t *addr, u8_t dns_addrtype)
@@ -2415,6 +2413,15 @@
  * @{
  */
 
+/**
+ * LWIP_HOOK_FILENAME: Custom filename to #include in files that provide hooks.
+ * Declare your hook function prototypes in there, you may also #include all headers
+ * providing data types that are need in this file.
+ */
+#ifdef __DOXYGEN__
+#define LWIP_HOOK_FILENAME "path/to/my/lwip_hooks.h"
+#endif
+
 /**
  * LWIP_HOOK_TCP_ISN:
  * Hook for generation of the Initial Sequence Number (ISN) for a new TCP

src/include/lwip/priv/tcp_priv.h

@@ -170,16 +170,18 @@ err_t            tcp_process_refused_data(struct tcp_pcb *pcb);
                 LWIP_EVENT_RECV, NULL, 0, ERR_OK)
 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
                 LWIP_EVENT_CONNECTED, NULL, 0, (err))
-#define TCP_EVENT_POLL(pcb,ret)       ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
+#define TCP_EVENT_POLL(pcb,ret)       do { if ((pcb)->state != SYN_RCVD) {                          \
-                LWIP_EVENT_POLL, NULL, 0, ERR_OK)
+                ret = lwip_tcp_event((pcb)->callback_arg, (pcb), LWIP_EVENT_POLL, NULL, 0, ERR_OK); \
-#define TCP_EVENT_ERR(errf,arg,err)  lwip_tcp_event((arg), NULL, \
+                } else {                                                                            \
-                LWIP_EVENT_ERR, NULL, 0, (err))
+                ret = ERR_ARG; } } while(0)
+#define TCP_EVENT_ERR(last_state,errf,arg,err)  do { if (last_state != SYN_RCVD) {                \
+                lwip_tcp_event((arg), NULL, LWIP_EVENT_ERR, NULL, 0, (err)); } } while(0)
 
 #else /* LWIP_EVENT_API */
 
 #define TCP_EVENT_ACCEPT(lpcb,pcb,arg,err,ret)                 \
   do {                                                         \
-    if((lpcb != NULL) && ((lpcb)->accept != NULL))             \
+    if((lpcb)->accept != NULL)                                 \
       (ret) = (lpcb)->accept((arg),(pcb),(err));               \
     else (ret) = ERR_ARG;                                      \
   } while (0)
@@ -223,8 +225,9 @@ err_t            tcp_process_refused_data(struct tcp_pcb *pcb);
     else (ret) = ERR_OK;                                       \
   } while (0)
 
-#define TCP_EVENT_ERR(errf,arg,err)                            \
+#define TCP_EVENT_ERR(last_state,errf,arg,err)                 \
   do {                                                         \
+    LWIP_UNUSED_ARG(last_state);                               \
     if((errf) != NULL)                                         \
       (errf)((arg),(err));                                     \
   } while (0)
@@ -249,7 +252,7 @@ struct tcp_seg {
 #if TCP_OVERSIZE_DBGCHECK
   u16_t oversize_left;     /* Extra bytes available at the end of the last
                               pbuf in unsent (used for asserting vs.
-                              tcp_pcb.unsent_oversized only) */
+                              tcp_pcb.unsent_oversize only) */
 #endif /* TCP_OVERSIZE_DBGCHECK */
 #if TCP_CHECKSUM_ON_COPY
   u16_t chksum;

src/include/lwip/sockets.h

@@ -46,7 +46,7 @@
 #include "lwip/ip_addr.h"
 #include "lwip/err.h"
 #include "lwip/inet.h"
-#include "lwip/errno.h"
+#include "lwip/lwip_errno.h"
 
 #ifdef __cplusplus
 extern "C" {

src/include/lwip/tcp.h

@@ -145,7 +145,7 @@ typedef u32_t tcpwnd_size_t;
 typedef u16_t tcpwnd_size_t;
 #endif
 
-#if LWIP_WND_SCALE || TCP_LISTEN_BACKLOG
+#if LWIP_WND_SCALE || TCP_LISTEN_BACKLOG || LWIP_TCP_TIMESTAMPS
 typedef u16_t tcpflags_t;
 #else
 typedef u8_t tcpflags_t;
@@ -210,7 +210,7 @@ struct tcp_pcb {
 #define TF_ACK_DELAY   0x01U   /* Delayed ACK. */
 #define TF_ACK_NOW     0x02U   /* Immediate ACK. */
 #define TF_INFR        0x04U   /* In fast recovery. */
-#define TF_TIMESTAMP   0x08U   /* Timestamp option enabled */
+#define TF_CLOSEPEND   0x08U   /* If this is set, tcp_close failed to enqueue the FIN (retried in tcp_tmr) */
 #define TF_RXCLOSED    0x10U   /* rx closed by tcp_shutdown */
 #define TF_FIN         0x20U   /* Connection was closed locally (FIN segment enqueued). */
 #define TF_NODELAY     0x40U   /* Disable Nagle algorithm */
@@ -220,6 +220,9 @@ struct tcp_pcb {
 #endif
 #if TCP_LISTEN_BACKLOG
 #define TF_BACKLOGPEND 0x0200U /* If this is set, a connection pcb has increased the backlog on its listener */
+#endif
+#if LWIP_TCP_TIMESTAMPS
+#define TF_TIMESTAMP   0x0400U   /* Timestamp option enabled */
 #endif
 
   /* the rest of the fields are in host byte order
@@ -358,7 +361,11 @@ void             tcp_accept  (struct tcp_pcb *pcb, tcp_accept_fn accept);
 #endif /* LWIP_CALLBACK_API */
 void             tcp_poll    (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval);
 
+#if LWIP_TCP_TIMESTAMPS
 #define          tcp_mss(pcb)             (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12)  : (pcb)->mss)
+#else /* LWIP_TCP_TIMESTAMPS */
+#define          tcp_mss(pcb)             ((pcb)->mss)
+#endif /* LWIP_TCP_TIMESTAMPS */
 #define          tcp_sndbuf(pcb)          (TCPWND16((pcb)->snd_buf))
 #define          tcp_sndqueuelen(pcb)     ((pcb)->snd_queuelen)
 /** @ingroup tcp_raw */

src/include/netif/ppp/ppp_impl.h

@@ -138,10 +138,10 @@
  */
 struct link_callbacks {
   /* Start a connection (e.g. Initiate discovery phase) */
-  err_t (*connect) (ppp_pcb *pcb, void *ctx);
+  void (*connect) (ppp_pcb *pcb, void *ctx);
 #if PPP_SERVER
   /* Listen for an incoming connection (Passive mode) */
-  err_t (*listen) (ppp_pcb *pcb, void *ctx);
+  void (*listen) (ppp_pcb *pcb, void *ctx);
 #endif /* PPP_SERVER */
   /* End a connection (i.e. initiate disconnect phase) */
   void (*disconnect) (ppp_pcb *pcb, void *ctx);

src/include/posix/errno.h

@@ -30,4 +30,4 @@
  *
  */
 
-#include "lwip/errno.h"
+#include "lwip/lwip_errno.h"

src/netif/lwip_ethernet.c

@@ -56,6 +56,10 @@
 #include "netif/ppp/pppoe.h"
 #endif /* PPPOE_SUPPORT */
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
 const struct eth_addr ethzero = {{0,0,0,0,0,0}};
 

src/netif/ppp/lwip_ppp.c

@@ -275,8 +275,8 @@ err_t ppp_connect(ppp_pcb *pcb, u16_t holdoff) {
   PPPDEBUG(LOG_DEBUG, ("ppp_connect[%d]: holdoff=%d\n", pcb->netif->num, holdoff));
 
   if (holdoff == 0) {
-    new_phase(pcb, PPP_PHASE_INITIALIZE);
+    ppp_do_connect(pcb);
-    return pcb->link_cb->connect(pcb, pcb->link_ctx_cb);
+    return ERR_OK;
   }
 
   new_phase(pcb, PPP_PHASE_HOLDOFF);
@@ -302,7 +302,8 @@ err_t ppp_listen(ppp_pcb *pcb) {
 
   if (pcb->link_cb->listen) {
     new_phase(pcb, PPP_PHASE_INITIALIZE);
-    return pcb->link_cb->listen(pcb, pcb->link_ctx_cb);
+    pcb->link_cb->listen(pcb, pcb->link_ctx_cb);
+    return ERR_OK;
   }
   return ERR_IF;
 }

src/netif/ppp/lwip_pppoe.c

@@ -119,7 +119,7 @@ LWIP_MEMPOOL_DECLARE(PPPOE_IF, MEMP_NUM_PPPOE_INTERFACES, sizeof(struct pppoe_so
 /* callbacks called from PPP core */
 static err_t pppoe_write(ppp_pcb *ppp, void *ctx, struct pbuf *p);
 static err_t pppoe_netif_output(ppp_pcb *ppp, void *ctx, struct pbuf *p, u_short protocol);
-static err_t pppoe_connect(ppp_pcb *ppp, void *ctx);
+static void pppoe_connect(ppp_pcb *ppp, void *ctx);
 static void pppoe_disconnect(ppp_pcb *ppp, void *ctx);
 static err_t pppoe_destroy(ppp_pcb *ppp, void *ctx);
 
@@ -879,7 +879,7 @@ pppoe_timeout(void *arg)
 }
 
 /* Start a connection (i.e. initiate discovery phase) */
-static err_t
+static void
 pppoe_connect(ppp_pcb *ppp, void *ctx)
 {
   err_t err;
@@ -934,7 +934,6 @@ pppoe_connect(ppp_pcb *ppp, void *ctx)
     PPPDEBUG(LOG_DEBUG, ("pppoe: %c%c%"U16_F": failed to send PADI, error=%d\n", sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num, err));
   }
   sys_timeout(PPPOE_DISC_TIMEOUT, pppoe_timeout, sc);
-  return err;
 }
 
 /* disconnect */

src/netif/ppp/lwip_pppol2tp.c

@@ -73,7 +73,7 @@ LWIP_MEMPOOL_DECLARE(PPPOL2TP_PCB, MEMP_NUM_PPPOL2TP_INTERFACES, sizeof(pppol2tp
 static err_t pppol2tp_write(ppp_pcb *ppp, void *ctx, struct pbuf *p);
 static err_t pppol2tp_netif_output(ppp_pcb *ppp, void *ctx, struct pbuf *p, u_short protocol);
 static err_t pppol2tp_destroy(ppp_pcb *ppp, void *ctx);    /* Destroy a L2TP control block */
-static err_t pppol2tp_connect(ppp_pcb *ppp, void *ctx);    /* Be a LAC, connect to a LNS. */
+static void pppol2tp_connect(ppp_pcb *ppp, void *ctx);    /* Be a LAC, connect to a LNS. */
 static void pppol2tp_disconnect(ppp_pcb *ppp, void *ctx);  /* Disconnect */
 
  /* Prototypes for procedures local to this file. */
@@ -255,7 +255,7 @@ static err_t pppol2tp_destroy(ppp_pcb *ppp, void *ctx) {
 }
 
 /* Be a LAC, connect to a LNS. */
-static err_t pppol2tp_connect(ppp_pcb *ppp, void *ctx) {
+static void pppol2tp_connect(ppp_pcb *ppp, void *ctx) {
   err_t err;
   pppol2tp_pcb *l2tp = (pppol2tp_pcb *)ctx;
   lcp_options *lcp_wo;
@@ -326,7 +326,6 @@ static err_t pppol2tp_connect(ppp_pcb *ppp, void *ctx) {
     PPPDEBUG(LOG_DEBUG, ("pppol2tp: failed to send SCCRQ, error=%d\n", err));
   }
   sys_timeout(PPPOL2TP_CONTROL_TIMEOUT, pppol2tp_timeout, l2tp);
-  return err;
 }
 
 /* Disconnect */

src/netif/ppp/lwip_pppos.c

@@ -57,9 +57,9 @@ LWIP_MEMPOOL_DECLARE(PPPOS_PCB, MEMP_NUM_PPPOS_INTERFACES, sizeof(pppos_pcb), "P
 /* callbacks called from PPP core */
 static err_t pppos_write(ppp_pcb *ppp, void *ctx, struct pbuf *p);
 static err_t pppos_netif_output(ppp_pcb *ppp, void *ctx, struct pbuf *pb, u16_t protocol);
-static err_t pppos_connect(ppp_pcb *ppp, void *ctx);
+static void pppos_connect(ppp_pcb *ppp, void *ctx);
 #if PPP_SERVER
-static err_t pppos_listen(ppp_pcb *ppp, void *ctx);
+static void pppos_listen(ppp_pcb *ppp, void *ctx);
 #endif /* PPP_SERVER */
 static void pppos_disconnect(ppp_pcb *ppp, void *ctx);
 static err_t pppos_destroy(ppp_pcb *ppp, void *ctx);
@@ -298,7 +298,7 @@ pppos_netif_output(ppp_pcb *ppp, void *ctx, struct pbuf *pb, u16_t protocol)
   return err;
 }
 
-static err_t
+static void
 pppos_connect(ppp_pcb *ppp, void *ctx)
 {
   pppos_pcb *pppos = (pppos_pcb *)ctx;
@@ -327,11 +327,10 @@ pppos_connect(ppp_pcb *ppp, void *ctx)
    */
   PPPDEBUG(LOG_INFO, ("pppos_connect: unit %d: connecting\n", ppp->netif->num));
   ppp_start(ppp); /* notify upper layers */
-  return ERR_OK;
 }
 
 #if PPP_SERVER
-static err_t
+static void
 pppos_listen(ppp_pcb *ppp, void *ctx)
 {
   pppos_pcb *pppos = (pppos_pcb *)ctx;
@@ -360,7 +359,6 @@ pppos_listen(ppp_pcb *ppp, void *ctx)
    */
   PPPDEBUG(LOG_INFO, ("pppos_listen: unit %d: listening\n", ppp->netif->num));
   ppp_start(ppp); /* notify upper layers */
-  return ERR_OK;
 }
 #endif /* PPP_SERVER */
 

test/unit/tcp/tcp_helper.c

@@ -155,19 +155,19 @@ tcp_set_state(struct tcp_pcb* pcb, enum tcp_state state, ip_addr_t* local_ip,
   
   if (state == ESTABLISHED) {
     TCP_REG(&tcp_active_pcbs, pcb);
-    pcb->local_ip.addr = local_ip->addr;
+    ip_addr_copy(pcb->local_ip, *local_ip);
     pcb->local_port = local_port;
-    pcb->remote_ip.addr = remote_ip->addr;
+    ip_addr_copy(pcb->remote_ip, *remote_ip);
     pcb->remote_port = remote_port;
   } else if(state == LISTEN) {
     TCP_REG(&tcp_listen_pcbs.pcbs, pcb);
-    pcb->local_ip.addr = local_ip->addr;
+    ip_addr_copy(pcb->local_ip, *local_ip);
     pcb->local_port = local_port;
   } else if(state == TIME_WAIT) {
     TCP_REG(&tcp_tw_pcbs, pcb);
-    pcb->local_ip.addr = local_ip->addr;
+    ip_addr_copy(pcb->local_ip, *local_ip);
     pcb->local_port = local_port;
-    pcb->remote_ip.addr = remote_ip->addr;
+    ip_addr_copy(pcb->remote_ip, *remote_ip);
     pcb->remote_port = remote_port;
   } else {
     fail();
@@ -302,8 +302,8 @@ void test_tcp_init_netif(struct netif *netif, struct test_tcp_txcounters *txcoun
   }
   netif->output = test_tcp_netif_output;
   netif->flags |= NETIF_FLAG_UP | NETIF_FLAG_LINK_UP;
-  ip4_addr_copy(netif->netmask, *ip_2_ip4(netmask));
+  ip_addr_copy_from_ip4(netif->netmask, *ip_2_ip4(netmask));
-  ip4_addr_copy(netif->ip_addr, *ip_2_ip4(ip_addr));
+  ip_addr_copy_from_ip4(netif->ip_addr, *ip_2_ip4(ip_addr));
   for (n = netif_list; n != NULL; n = n->next) {
     if (n == netif) {
       return;

test/unit/tcp/test_tcp.c

@@ -46,9 +46,9 @@ tcp_setup(void)
 static void
 tcp_teardown(void)
 {
-  tcp_remove_all();
   netif_list = NULL;
   netif_default = NULL;
+  tcp_remove_all();
 }
 
 
@@ -422,6 +422,8 @@ START_TEST(test_tcp_fast_rexmit_wraparound)
   pcb->mss = TCP_MSS;
   /* disable initial congestion window (we don't send a SYN here...) */
   pcb->cwnd = 2*TCP_MSS;
+  /* start in congestion advoidance */
+  pcb->ssthresh = pcb->cwnd;
 
   /* send 6 mss-sized segments */
   for (i = 0; i < 6; i++) {
@@ -442,7 +444,9 @@ START_TEST(test_tcp_fast_rexmit_wraparound)
   /* ACK the first segment */
   p = tcp_create_rx_segment(pcb, NULL, 0, 0, TCP_MSS, TCP_ACK);
   test_tcp_input(p, &netif);
-  /* ensure this didn't trigger a retransmission */
+  /* ensure this didn't trigger a retransmission. Only one
+  segment should be transmitted because cwnd opened up by
+  TCP_MSS and a fraction since we are in congestion avoidance */
   EXPECT(txcounters.num_tx_calls == 1);
   EXPECT(txcounters.num_tx_bytes == TCP_MSS + 40U);
   memset(&txcounters, 0, sizeof(txcounters));