From ad12583f46bcb6ce93ccd99fa063c0d701146b2e Mon Sep 17 00:00:00 2001 From: David L Stevens Date: Wed, 18 Jan 2006 14:20:56 -0800 Subject: [PATCH] [IPV4]: Fix multiple bugs in IGMPv3 1) fix "mld_marksources()" to a) send nothing when all queried sources are excluded b) send full exclude report when source queried sources are not excluded c) don't schedule a timer when there's nothing to report 2) fix "add_grec()" to send empty-source records when it should The original check doesn't account for a non-empty source list with all sources inactive; the new code keeps that short-circuit case, and also generates the group header with an empty list if needed. 3) fix mca_crcount decrement to be after add_grec(), which needs its original value 4) add/remove delete records and prevent current advertisements when an exclude-mode filter moves from "active" to "inactive" or vice versa based on new filter additions. Items 1-3 are just IPv4 versions of the IPv6 bugs found by Yan Zheng and fixed earlier. Item #4 is a related bug that affects exclude-mode change records only (but not queries) and also occurs in IPv6 (IPv6 version coming soon). Signed-off-by: David L Stevens Signed-off-by: David S. Miller --- net/ipv4/igmp.c | 152 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 122 insertions(+), 30 deletions(-) diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 192092b89e53..d8ce7133cd8f 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -233,7 +233,18 @@ static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type, case IGMPV3_MODE_IS_EXCLUDE: if (gdeleted || sdeleted) return 0; - return !(pmc->gsquery && !psf->sf_gsresp); + if (!(pmc->gsquery && !psf->sf_gsresp)) { + if (pmc->sfmode == MCAST_INCLUDE) + return 1; + /* don't include if this source is excluded + * in all filters + */ + if (psf->sf_count[MCAST_INCLUDE]) + return type == IGMPV3_MODE_IS_INCLUDE; + return pmc->sfcount[MCAST_EXCLUDE] == + psf->sf_count[MCAST_EXCLUDE]; + } + return 0; case IGMPV3_CHANGE_TO_INCLUDE: if (gdeleted || sdeleted) return 0; @@ -385,7 +396,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, struct igmpv3_report *pih; struct igmpv3_grec *pgr = NULL; struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list; - int scount, first, isquery, truncate; + int scount, stotal, first, isquery, truncate; if (pmc->multiaddr == IGMP_ALL_HOSTS) return skb; @@ -395,25 +406,13 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, truncate = type == IGMPV3_MODE_IS_EXCLUDE || type == IGMPV3_CHANGE_TO_EXCLUDE; + stotal = scount = 0; + psf_list = sdeleted ? &pmc->tomb : &pmc->sources; - if (!*psf_list) { - if (type == IGMPV3_ALLOW_NEW_SOURCES || - type == IGMPV3_BLOCK_OLD_SOURCES) - return skb; - if (pmc->crcount || isquery) { - /* make sure we have room for group header and at - * least one source. - */ - if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)+ - sizeof(__u32)) { - igmpv3_sendpack(skb); - skb = NULL; /* add_grhead will get a new one */ - } - skb = add_grhead(skb, pmc, type, &pgr); - } - return skb; - } + if (!*psf_list) + goto empty_source; + pih = skb ? (struct igmpv3_report *)skb->h.igmph : NULL; /* EX and TO_EX get a fresh packet, if needed */ @@ -426,7 +425,6 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, } } first = 1; - scount = 0; psf_prev = NULL; for (psf=*psf_list; psf; psf=psf_next) { u32 *psrc; @@ -460,7 +458,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, } psrc = (u32 *)skb_put(skb, sizeof(u32)); *psrc = psf->sf_inaddr; - scount++; + scount++; stotal++; if ((type == IGMPV3_ALLOW_NEW_SOURCES || type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) { psf->sf_crcount--; @@ -475,6 +473,21 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, } psf_prev = psf; } + +empty_source: + if (!stotal) { + if (type == IGMPV3_ALLOW_NEW_SOURCES || + type == IGMPV3_BLOCK_OLD_SOURCES) + return skb; + if (pmc->crcount || isquery) { + /* make sure we have room for group header */ + if (skb && AVAILABLE(skb)grec_nsrcs = htons(scount); @@ -557,11 +570,11 @@ static void igmpv3_send_cr(struct in_device *in_dev) skb = add_grec(skb, pmc, dtype, 1, 1); } if (pmc->crcount) { - pmc->crcount--; if (pmc->sfmode == MCAST_EXCLUDE) { type = IGMPV3_CHANGE_TO_INCLUDE; skb = add_grec(skb, pmc, type, 1, 0); } + pmc->crcount--; if (pmc->crcount == 0) { igmpv3_clear_zeros(&pmc->tomb); igmpv3_clear_zeros(&pmc->sources); @@ -594,12 +607,12 @@ static void igmpv3_send_cr(struct in_device *in_dev) /* filter mode changes */ if (pmc->crcount) { - pmc->crcount--; if (pmc->sfmode == MCAST_EXCLUDE) type = IGMPV3_CHANGE_TO_EXCLUDE; else type = IGMPV3_CHANGE_TO_INCLUDE; skb = add_grec(skb, pmc, type, 0, 0); + pmc->crcount--; } spin_unlock_bh(&pmc->lock); } @@ -735,11 +748,43 @@ static void igmp_timer_expire(unsigned long data) ip_ma_put(im); } -static void igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __u32 *srcs) +/* mark EXCLUDE-mode sources */ +static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __u32 *srcs) +{ + struct ip_sf_list *psf; + int i, scount; + + scount = 0; + for (psf=pmc->sources; psf; psf=psf->sf_next) { + if (scount == nsrcs) + break; + for (i=0; isfcount[MCAST_INCLUDE] || + pmc->sfcount[MCAST_EXCLUDE] != + psf->sf_count[MCAST_EXCLUDE]) + continue; + if (srcs[i] == psf->sf_inaddr) { + scount++; + break; + } + } + } + pmc->gsquery = 0; + if (scount == nsrcs) /* all sources excluded */ + return 0; + return 1; +} + +static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __u32 *srcs) { struct ip_sf_list *psf; int i, scount; + if (pmc->sfmode == MCAST_EXCLUDE) + return igmp_xmarksources(pmc, nsrcs, srcs); + + /* mark INCLUDE-mode sources */ scount = 0; for (psf=pmc->sources; psf; psf=psf->sf_next) { if (scount == nsrcs) @@ -751,6 +796,12 @@ static void igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __u32 *srcs) break; } } + if (!scount) { + pmc->gsquery = 0; + return 0; + } + pmc->gsquery = 1; + return 1; } static void igmp_heard_report(struct in_device *in_dev, u32 group) @@ -845,6 +896,8 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, */ read_lock(&in_dev->mc_list_lock); for (im=in_dev->mc_list; im!=NULL; im=im->next) { + int changed; + if (group && group != im->multiaddr) continue; if (im->multiaddr == IGMP_ALL_HOSTS) @@ -854,10 +907,11 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, im->gsquery = im->gsquery && mark; else im->gsquery = mark; - if (im->gsquery) - igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs); + changed = !im->gsquery || + igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs); spin_unlock_bh(&im->lock); - igmp_mod_timer(im, max_delay); + if (changed) + igmp_mod_timer(im, max_delay); } read_unlock(&in_dev->mc_list_lock); } @@ -1510,7 +1564,7 @@ static void sf_markstate(struct ip_mc_list *pmc) static int sf_setstate(struct ip_mc_list *pmc) { - struct ip_sf_list *psf; + struct ip_sf_list *psf, *dpsf; int mca_xcount = pmc->sfcount[MCAST_EXCLUDE]; int qrv = pmc->interface->mr_qrv; int new_in, rv; @@ -1522,8 +1576,46 @@ static int sf_setstate(struct ip_mc_list *pmc) !psf->sf_count[MCAST_INCLUDE]; } else new_in = psf->sf_count[MCAST_INCLUDE] != 0; - if (new_in != psf->sf_oldin) { - psf->sf_crcount = qrv; + if (new_in) { + if (!psf->sf_oldin) { + struct ip_sf_list *prev = 0; + + for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) { + if (dpsf->sf_inaddr == psf->sf_inaddr) + break; + prev = dpsf; + } + if (dpsf) { + if (prev) + prev->sf_next = dpsf->sf_next; + else + pmc->tomb = dpsf->sf_next; + kfree(dpsf); + } + psf->sf_crcount = qrv; + rv++; + } + } else if (psf->sf_oldin) { + + psf->sf_crcount = 0; + /* + * add or update "delete" records if an active filter + * is now inactive + */ + for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) + if (dpsf->sf_inaddr == psf->sf_inaddr) + break; + if (!dpsf) { + dpsf = (struct ip_sf_list *) + kmalloc(sizeof(*dpsf), GFP_ATOMIC); + if (!dpsf) + continue; + *dpsf = *psf; + /* pmc->lock held by callers */ + dpsf->sf_next = pmc->tomb; + pmc->tomb = dpsf; + } + dpsf->sf_crcount = qrv; rv++; } } -- GitLab