diff options
Diffstat (limited to 'zebra/rtadv.c')
| -rw-r--r-- | zebra/rtadv.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/zebra/rtadv.c b/zebra/rtadv.c index c95e75d8..082a1b36 100644 --- a/zebra/rtadv.c +++ b/zebra/rtadv.c @@ -157,14 +157,7 @@ rtadv_send_packet (int sock, struct interface *ifp) #ifdef HAVE_SOCKADDR_DL struct sockaddr_dl *sdl; #endif /* HAVE_SOCKADDR_DL */ - /* - * XXX: Alignment padding follows cmsghdr, and there is not - * necessarily a portable way to determine this. Add 16 bytes as a - * pessimistic assumption. (NetBSD/i386 aligns to 4, and - * NetBSD/sparc to 8.) Note check below that buf is not - * overwritten. A better fix is needed. - */ - char adata [sizeof (struct cmsghdr) + 16 + sizeof (struct in6_pktinfo)]; + static void *adata = NULL; unsigned char buf[RTADV_MSG_SIZE]; struct nd_router_advert *rtadv; int ret; @@ -173,6 +166,21 @@ rtadv_send_packet (int sock, struct interface *ifp) u_char all_nodes_addr[] = {0xff,0x02,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; listnode node; + /* + * Allocate control message bufffer. This is dynamic because + * CMSG_SPACE is not guaranteed not to call a function. Note that + * the size will be different on different architectures due to + * differing alignment rules. + */ + if (adata == NULL) + { + /* XXX Free on shutdown. */ + adata = malloc(CMSG_SPACE(sizeof(struct in6_pktinfo))); + + if (adata == NULL) + zlog_err("rtadv_send_packet: can't malloc control data\n"); + } + /* Logging of packet. */ if (IS_ZEBRA_DEBUG_PACKET) zlog_info ("Router advertisement send to %s", ifp->name); @@ -275,25 +283,17 @@ rtadv_send_packet (int sock, struct interface *ifp) msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_control = (void *) adata; - msg.msg_controllen = sizeof adata; - msg.msg_flags = MSG_DONTROUTE; + msg.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)); + msg.msg_flags = 0; iov.iov_base = buf; iov.iov_len = len; - cmsgptr = (struct cmsghdr *)adata; - cmsgptr->cmsg_len = sizeof adata; + cmsgptr = CMSG_FIRSTHDR(&msg); + cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); cmsgptr->cmsg_level = IPPROTO_IPV6; cmsgptr->cmsg_type = IPV6_PKTINFO; - /* XXX Check that we do not overwrite buf. */ pkt = (struct in6_pktinfo *) CMSG_DATA (cmsgptr); - if ((void *) &pkt->ipi6_ifindex + sizeof(pkt->ipi6_ifindex) - > (void *) &addr) - { - zlog_err ("rtadv_send_packet: NOT overwriting address\n"); - return; - } - memset (&pkt->ipi6_addr, 0, sizeof (struct in6_addr)); pkt->ipi6_ifindex = ifp->ifindex; |