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| author | bms <bms@FreeBSD.org> | 2007-02-02 20:31:44 +0000 |
|---|---|---|
| committer | bms <bms@FreeBSD.org> | 2007-02-02 20:31:44 +0000 |
| commit | 4341e5c6f6475cb79a6835fe07b0e3655b199779 (patch) | |
| tree | da8aa262b6f924b346f4e795cdc8c4031ba7ed6f /sys/netinet/if_ether.c | |
| parent | 04771e3c14c96f6a22e1dd7aa2d9b4feeab44349 (diff) | |
| download | FreeBSD-src-4341e5c6f6475cb79a6835fe07b0e3655b199779.zip FreeBSD-src-4341e5c6f6475cb79a6835fe07b0e3655b199779.tar.gz | |
Comply with RFC 3927, by forcing ARP replies which contain a source
address within the link-local IPv4 prefix 169.254.0.0/16, to be
broadcast at link layer.
Reviewed by: fenner
MFC after: 2 weeks
Diffstat (limited to 'sys/netinet/if_ether.c')
| -rw-r--r-- | sys/netinet/if_ether.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c index 8ee7132..e736597 100644 --- a/sys/netinet/if_ether.c +++ b/sys/netinet/if_ether.c @@ -885,11 +885,23 @@ reply: } } + if (itaddr.s_addr == myaddr.s_addr && + IN_LINKLOCAL(ntohl(itaddr.s_addr))) { + /* RFC 3927 link-local IPv4; always reply by broadcast. */ +#ifdef DEBUG_LINKLOCAL + printf("arp: sending reply for link-local addr %s\n", + inet_ntoa(itaddr)); +#endif + m->m_flags |= M_BCAST; + m->m_flags &= ~M_MCAST; + } else { + /* default behaviour; never reply by broadcast. */ + m->m_flags &= ~(M_BCAST|M_MCAST); + } (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln); ah->ar_op = htons(ARPOP_REPLY); ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ - m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); m->m_pkthdr.len = m->m_len; sa.sa_family = AF_ARP; |
