mirror of https://github.com/mirror/busybox.git
udp_io: fix two more potential cases of unaligned accesses. 0 code size changes.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>1_16_stable
Denys Vlasenko
parent
57be1eefab
commit
1361aa2e2d
|
|
@ -6,7 +6,6 @@
|
|||
*
|
||||
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
|
||||
*/
|
||||
|
||||
#include "libbb.h"
|
||||
|
||||
/*
|
||||
|
|
@ -32,22 +31,23 @@ send_to_from(int fd, void *buf, size_t len, int flags,
|
|||
socklen_t tolen)
|
||||
{
|
||||
#ifndef IP_PKTINFO
|
||||
(void)from; /* suppress "unused from" warning */
|
||||
return sendto(fd, buf, len, flags, to, tolen);
|
||||
#else
|
||||
struct iovec iov[1];
|
||||
struct msghdr msg;
|
||||
union {
|
||||
char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
|
||||
#if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
|
||||
#endif
|
||||
# endif
|
||||
} u;
|
||||
struct cmsghdr* cmsgptr;
|
||||
|
||||
if (from->sa_family != AF_INET
|
||||
#if ENABLE_FEATURE_IPV6
|
||||
# if ENABLE_FEATURE_IPV6
|
||||
&& from->sa_family != AF_INET6
|
||||
#endif
|
||||
# endif
|
||||
) {
|
||||
/* ANY local address */
|
||||
return sendto(fd, buf, len, flags, to, tolen);
|
||||
|
|
@ -76,20 +76,26 @@ send_to_from(int fd, void *buf, size_t len, int flags,
|
|||
cmsgptr->cmsg_type = IP_PKTINFO;
|
||||
cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
|
||||
pktptr = (struct in_pktinfo *)(CMSG_DATA(cmsgptr));
|
||||
/* pktptr->ipi_ifindex = 0; -- already done by memset(cbuf...) */
|
||||
/*pktptr->ipi_ifindex = 0; -- already done by memset(u...) */
|
||||
/* In general, CMSG_DATA() can be unaligned, but in this case
|
||||
* we know for sure it is sufficiently aligned:
|
||||
* CMSG_FIRSTHDR simply returns &u above,
|
||||
* and CMSG_DATA returns &u + size_t + int + int.
|
||||
* Thus direct assignment is ok:
|
||||
*/
|
||||
pktptr->ipi_spec_dst = ((struct sockaddr_in*)from)->sin_addr;
|
||||
}
|
||||
#if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
else if (to->sa_family == AF_INET6 && from->sa_family == AF_INET6) {
|
||||
struct in6_pktinfo *pktptr;
|
||||
cmsgptr->cmsg_level = IPPROTO_IPV6;
|
||||
cmsgptr->cmsg_type = IPV6_PKTINFO;
|
||||
cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
|
||||
pktptr = (struct in6_pktinfo *)(CMSG_DATA(cmsgptr));
|
||||
/* pktptr->ipi6_ifindex = 0; -- already done by memset(cbuf...) */
|
||||
/* pktptr->ipi6_ifindex = 0; -- already done by memset(u...) */
|
||||
pktptr->ipi6_addr = ((struct sockaddr_in6*)from)->sin6_addr;
|
||||
}
|
||||
#endif
|
||||
# endif
|
||||
msg.msg_controllen = cmsgptr->cmsg_len;
|
||||
|
||||
return sendmsg(fd, &msg, flags);
|
||||
|
|
@ -106,15 +112,16 @@ recv_from_to(int fd, void *buf, size_t len, int flags,
|
|||
socklen_t sa_size)
|
||||
{
|
||||
#ifndef IP_PKTINFO
|
||||
(void)to; /* suppress "unused to" warning */
|
||||
return recvfrom(fd, buf, len, flags, from, &sa_size);
|
||||
#else
|
||||
/* man recvmsg and man cmsg is needed to make sense of code below */
|
||||
struct iovec iov[1];
|
||||
union {
|
||||
char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
|
||||
#if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
|
||||
#endif
|
||||
# endif
|
||||
} u;
|
||||
struct cmsghdr *cmsgptr;
|
||||
struct msghdr msg;
|
||||
|
|
@ -135,6 +142,8 @@ recv_from_to(int fd, void *buf, size_t len, int flags,
|
|||
if (recv_length < 0)
|
||||
return recv_length;
|
||||
|
||||
# define to4 ((struct sockaddr_in*)to)
|
||||
# define to6 ((struct sockaddr_in6*)to)
|
||||
/* Here we try to retrieve destination IP and memorize it */
|
||||
for (cmsgptr = CMSG_FIRSTHDR(&msg);
|
||||
cmsgptr != NULL;
|
||||
|
|
@ -143,25 +152,27 @@ recv_from_to(int fd, void *buf, size_t len, int flags,
|
|||
if (cmsgptr->cmsg_level == IPPROTO_IP
|
||||
&& cmsgptr->cmsg_type == IP_PKTINFO
|
||||
) {
|
||||
#define pktinfo(cmsgptr) ( (struct in_pktinfo*)(CMSG_DATA(cmsgptr)) )
|
||||
# define pktinfo(cmsgptr) ( (struct in_pktinfo*)(CMSG_DATA(cmsgptr)) )
|
||||
to->sa_family = AF_INET;
|
||||
((struct sockaddr_in*)to)->sin_addr = pktinfo(cmsgptr)->ipi_addr;
|
||||
/* ((struct sockaddr_in*)to)->sin_port = 123; */
|
||||
#undef pktinfo
|
||||
/*to4->sin_addr = pktinfo(cmsgptr)->ipi_addr; - may be unaligned */
|
||||
memcpy(&to4->sin_addr, &pktinfo(cmsgptr)->ipi_addr, sizeof(to4->sin_addr));
|
||||
/*to4->sin_port = 123; - this data is not supplied by kernel */
|
||||
# undef pktinfo
|
||||
break;
|
||||
}
|
||||
#if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
|
||||
if (cmsgptr->cmsg_level == IPPROTO_IPV6
|
||||
&& cmsgptr->cmsg_type == IPV6_PKTINFO
|
||||
) {
|
||||
#define pktinfo(cmsgptr) ( (struct in6_pktinfo*)(CMSG_DATA(cmsgptr)) )
|
||||
# define pktinfo(cmsgptr) ( (struct in6_pktinfo*)(CMSG_DATA(cmsgptr)) )
|
||||
to->sa_family = AF_INET6;
|
||||
((struct sockaddr_in6*)to)->sin6_addr = pktinfo(cmsgptr)->ipi6_addr;
|
||||
/* ((struct sockaddr_in6*)to)->sin6_port = 123; */
|
||||
#undef pktinfo
|
||||
/*to6->sin6_addr = pktinfo(cmsgptr)->ipi6_addr; - may be unaligned */
|
||||
memcpy(&to6->sin6_addr, &pktinfo(cmsgptr)->ipi6_addr, sizeof(to6->sin6_addr));
|
||||
/*to6->sin6_port = 123; */
|
||||
# undef pktinfo
|
||||
break;
|
||||
}
|
||||
#endif
|
||||
# endif
|
||||
}
|
||||
return recv_length;
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue