From e42f869b5118fa9ac64dcea624276204567fc581 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Sun, 26 Mar 2017 20:28:11 +0200 Subject: slirp: Make RA build more flexible MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Do not hardcode the RA size at all, use a pl_size variable which accounts the accumulated size, and fill rip->ip_pl at the end. This will allow to make some blocks optional. Signed-off-by: Samuel Thibault Reviewed-by: Philippe Mathieu-Daudé --- slirp/ip6_icmp.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) (limited to 'slirp') diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c index 298a48dd25..d0f5cc1456 100644 --- a/slirp/ip6_icmp.c +++ b/slirp/ip6_icmp.c @@ -143,17 +143,10 @@ void ndp_send_ra(Slirp *slirp) /* Build IPv6 packet */ struct mbuf *t = m_get(slirp); struct ip6 *rip = mtod(t, struct ip6 *); + size_t pl_size = 0; rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR; rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST; rip->ip_nh = IPPROTO_ICMPV6; - rip->ip_pl = htons(ICMP6_NDP_RA_MINLEN - + NDPOPT_LINKLAYER_LEN - + NDPOPT_PREFIXINFO_LEN -#ifndef _WIN32 - + NDPOPT_RDNSS_LEN -#endif - ); - t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl); /* Build ICMPv6 packet */ t->m_data += sizeof(struct ip6); @@ -171,6 +164,7 @@ void ndp_send_ra(Slirp *slirp) ricmp->icmp6_nra.reach_time = htonl(NDP_AdvReachableTime); ricmp->icmp6_nra.retrans_time = htonl(NDP_AdvRetransTime); t->m_data += ICMP6_NDP_RA_MINLEN; + pl_size += ICMP6_NDP_RA_MINLEN; /* Source link-layer address (NDP option) */ struct ndpopt *opt = mtod(t, struct ndpopt *); @@ -178,6 +172,7 @@ void ndp_send_ra(Slirp *slirp) opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8; in6_compute_ethaddr(rip->ip_src, opt->ndpopt_linklayer); t->m_data += NDPOPT_LINKLAYER_LEN; + pl_size += NDPOPT_LINKLAYER_LEN; /* Prefix information (NDP option) */ struct ndpopt *opt2 = mtod(t, struct ndpopt *); @@ -192,6 +187,7 @@ void ndp_send_ra(Slirp *slirp) opt2->ndpopt_prefixinfo.reserved2 = 0; opt2->ndpopt_prefixinfo.prefix = slirp->vprefix_addr6; t->m_data += NDPOPT_PREFIXINFO_LEN; + pl_size += NDPOPT_PREFIXINFO_LEN; #ifndef _WIN32 /* Prefix information (NDP option) */ @@ -203,16 +199,14 @@ void ndp_send_ra(Slirp *slirp) opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval); opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6; t->m_data += NDPOPT_RDNSS_LEN; + pl_size += NDPOPT_RDNSS_LEN; #endif + rip->ip_pl = htons(pl_size); + t->m_data -= sizeof(struct ip6) + pl_size; + t->m_len = sizeof(struct ip6) + pl_size; + /* ICMPv6 Checksum */ -#ifndef _WIN32 - t->m_data -= NDPOPT_RDNSS_LEN; -#endif - t->m_data -= NDPOPT_PREFIXINFO_LEN; - t->m_data -= NDPOPT_LINKLAYER_LEN; - t->m_data -= ICMP6_NDP_RA_MINLEN; - t->m_data -= sizeof(struct ip6); ricmp->icmp6_cksum = ip6_cksum(t); ip6_output(NULL, t, 0); -- cgit v1.2.1