Make inet6_rth_* family of functions more compliant with RFC3542:

1. CMSG_NXTHDR(mhdr, cmsg) is supposed to dereference cmsg and return
   the next header in the chain. If cmsg is NULL it should return
   the first header, behaving essentially like CMSG_FIRSTHDR().
2. inet6_rth_(space|init|add) should do basic checking on their input
   to verify that the number of headers (segments) is
   between 0 and 127 inclusive.

MFC-After: 1 month
This commit is contained in:
Mike Makonnen 2007-04-19 15:48:16 +00:00
parent ad092d18d7
commit 18a6073100
2 changed files with 13 additions and 3 deletions

View File

@ -292,7 +292,9 @@ inet6_rth_space(int type, int segments)
{
switch (type) {
case IPV6_RTHDR_TYPE_0:
return (((segments * 2) + 1) << 3);
if ((segments >= 0) && (segments <= 127))
return (((segments * 2) + 1) << 3);
/* FALLTHROUGH */
default:
return (0); /* type not suppported */
}
@ -309,6 +311,9 @@ inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
/* length validation */
if (bp_len < inet6_rth_space(IPV6_RTHDR_TYPE_0, segments))
return (NULL);
/* segment validation */
if ((segments < 0) || (segments > 127))
return (NULL);
memset(bp, 0, bp_len);
rth0 = (struct ip6_rthdr0 *)rth;
@ -334,6 +339,9 @@ inet6_rth_add(void *bp, const struct in6_addr *addr)
switch (rth->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
rth0 = (struct ip6_rthdr0 *)rth;
/* Don't exceed the number of stated segments */
if (rth0->ip6r0_segleft == (rth0->ip6r0_len / 2))
return (-1);
nextaddr = (struct in6_addr *)(rth0 + 1) + rth0->ip6r0_segleft;
*nextaddr = *addr;
rth0->ip6r0_segleft++;

View File

@ -471,11 +471,13 @@ struct sockcred {
/* given pointer to struct cmsghdr, return pointer to next cmsghdr */
#define CMSG_NXTHDR(mhdr, cmsg) \
(((char *)(cmsg) + _ALIGN((cmsg)->cmsg_len) + \
((char *)(cmsg) == NULL ? CMSG_FIRSTHDR(mhdr) : \
((char *)(cmsg) + _ALIGN(((struct cmsghdr *)(cmsg))->cmsg_len) + \
_ALIGN(sizeof(struct cmsghdr)) > \
(char *)(mhdr)->msg_control + (mhdr)->msg_controllen) ? \
(struct cmsghdr *)0 : \
(struct cmsghdr *)((char *)(cmsg) + _ALIGN((cmsg)->cmsg_len)))
(struct cmsghdr *)((char *)(cmsg) + \
_ALIGN(((struct cmsghdr *)(cmsg))->cmsg_len)))
/*
* RFC 2292 requires to check msg_controllen, in case that the kernel returns