[PATCH 2/2][MCAST] Fix for add_grec(...)
From: Yan Zheng <hidden>
Date: 2005-11-09 11:56:20
Also in:
lkml
Hi When ifmcaddr6's mca_sources is not NULL, but none of the sources in the list can be included in report, (For example: when filter mode is exclude and the only source in the list has include count greater than zero.) add_grec(...) may returns without add any data to the sk_buff. So MLD2_CHANGE_TO_EXCLUDE or MLD2_MODE_IS_EXCLUDE report may be eliminated. You can check this bug by test1.c in attachments. You will notice that there is no MLD2_CHANGE_TO_EXCLUDE report. Regards Signed-off-by: Yan Zheng<redacted> Index:net/ipv6/mcast.c ==============================================================
--- linux-2.6.14/net/ipv6/mcast.c 2005-11-09 16:00:48.000000000 +0800
+++ linux/net/ipv6/mcast.c 2005-11-09 19:47:50.000000000 +0800@@ -1445,18 +1445,21 @@ static struct sk_buff *add_grec(struct s struct mld2_report *pmr; struct mld2_grec *pgr = NULL; struct ip6_sf_list *psf, *psf_next, *psf_prev, **psf_list; - int scount, first, isquery, truncate; + int scount, first, isquery, ischange, truncate; if (pmc->mca_flags & MAF_NOREPORT) return skb; isquery = type == MLD2_MODE_IS_INCLUDE || type == MLD2_MODE_IS_EXCLUDE; + ischange = type == MLD2_CHANGE_TO_INCLUDE || + type == MLD2_CHANGE_TO_EXCLUDE; truncate = type == MLD2_MODE_IS_EXCLUDE || - type == MLD2_CHANGE_TO_EXCLUDE; + type == MLD2_CHANGE_TO_EXCLUDE; psf_list = sdeleted ? &pmc->mca_tomb : &pmc->mca_sources; +#if 0 if (!*psf_list) { if (type == MLD2_ALLOW_NEW_SOURCES || type == MLD2_BLOCK_OLD_SOURCES)
@@ -1474,12 +1477,15 @@ static struct sk_buff *add_grec(struct s } return skb; } +#endif pmr = skb ? (struct mld2_report *)skb->h.raw : NULL; /* EX and TO_EX get a fresh packet, if needed */ - if (truncate) { - if (pmr && pmr->ngrec && - AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) { + if (truncate || ischange) { + int min_len; + min_len = truncate ? grec_size(pmc, type, gdeleted, sdeleted) : + (sizeof(struct mld2_grec) + sizeof(struct in6_addr)); + if (pmr && pmr->ngrec && AVAILABLE(skb) < min_len) { if (skb) mld_sendpack(skb); skb = mld_newpack(dev, dev->mtu);
@@ -1488,6 +1494,10 @@ static struct sk_buff *add_grec(struct s first = 1; scount = 0; psf_prev = NULL; + if (ischange || type == MLD2_MODE_IS_EXCLUDE) { + skb = add_grhead(skb, pmc, type, &pgr); + first = 0; + } for (psf=*psf_list; psf; psf=psf_next) { struct in6_addr *psrc;