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Based on RFC3376 5.1 If no interface state existed for that multicast address before the change (i.e., the change consisted of creating a new per-interface record), or if no state exists after the change (i.e., the change consisted of deleting a per-interface record), then the "non-existent" state is considered to have a filter mode of INCLUDE and an empty source list. Which means a new multicast group should start with state IN(). Function ip_mc_join_group() works correctly for IGMP ASM(Any-Source Multicast) mode. It adds a group with state EX() and inits crcount to mc_qrv, so the kernel will send a TO_EX() report message after adding group. But for IGMPv3 SSM(Source-specific multicast) JOIN_SOURCE_GROUP mode, we split the group joining into two steps. First we join the group like ASM, i.e. via ip_mc_join_group(). So the state changes from IN() to EX(). Then we add the source-specific address with INCLUDE mode. So the state changes from EX() to IN(A). Before the first step sends a group change record, we finished the second step. So we will only send the second change record. i.e. TO_IN(A). Regarding the RFC stands, we should actually send an ALLOW(A) message for SSM JOIN_SOURCE_GROUP as the state should mimic the 'IN() to IN(A)' transition. The issue was exposed by commita052517a8f
("net/multicast: should not send source list records when have filter mode change"). Before this change, we used to send both ALLOW(A) and TO_IN(A). After this change we only send TO_IN(A). Fix it by adding a new parameter to init group mode. Also add new wrapper functions so we don't need to change too much code. v1 -> v2: In my first version I only cleared the group change record. But this is not enough. Because when a new group join, it will init as EXCLUDE and trigger an filter mode change in ip/ip6_mc_add_src(), which will clear all source addresses' sf_crcount. This will prevent early joined address sending state change records if multi source addressed joined at the same time. In v2 patch, I fixed it by directly initializing the mode to INCLUDE for SSM JOIN_SOURCE_GROUP. I also split the original patch into two separated patches for IPv4 and IPv6. Fixes:a052517a8f
("net/multicast: should not send source list records when have filter mode change") Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
135 lines
4.2 KiB
C
135 lines
4.2 KiB
C
/*
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* Linux NET3: Internet Group Management Protocol [IGMP]
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*
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* Authors:
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* Alan Cox <alan@lxorguk.ukuu.org.uk>
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*
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* Extended to talk the BSD extended IGMP protocol of mrouted 3.6
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _LINUX_IGMP_H
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#define _LINUX_IGMP_H
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#include <linux/skbuff.h>
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#include <linux/timer.h>
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#include <linux/in.h>
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#include <linux/refcount.h>
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#include <uapi/linux/igmp.h>
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static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
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{
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return (struct igmphdr *)skb_transport_header(skb);
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}
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static inline struct igmpv3_report *
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igmpv3_report_hdr(const struct sk_buff *skb)
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{
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return (struct igmpv3_report *)skb_transport_header(skb);
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}
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static inline struct igmpv3_query *
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igmpv3_query_hdr(const struct sk_buff *skb)
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{
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return (struct igmpv3_query *)skb_transport_header(skb);
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}
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struct ip_sf_socklist {
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unsigned int sl_max;
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unsigned int sl_count;
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struct rcu_head rcu;
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__be32 sl_addr[0];
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};
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#define IP_SFLSIZE(count) (sizeof(struct ip_sf_socklist) + \
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(count) * sizeof(__be32))
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#define IP_SFBLOCK 10 /* allocate this many at once */
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/* ip_mc_socklist is real list now. Speed is not argument;
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this list never used in fast path code
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*/
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struct ip_mc_socklist {
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struct ip_mc_socklist __rcu *next_rcu;
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struct ip_mreqn multi;
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unsigned int sfmode; /* MCAST_{INCLUDE,EXCLUDE} */
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struct ip_sf_socklist __rcu *sflist;
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struct rcu_head rcu;
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};
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struct ip_sf_list {
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struct ip_sf_list *sf_next;
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__be32 sf_inaddr;
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unsigned long sf_count[2]; /* include/exclude counts */
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unsigned char sf_gsresp; /* include in g & s response? */
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unsigned char sf_oldin; /* change state */
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unsigned char sf_crcount; /* retrans. left to send */
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};
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struct ip_mc_list {
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struct in_device *interface;
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__be32 multiaddr;
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unsigned int sfmode;
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struct ip_sf_list *sources;
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struct ip_sf_list *tomb;
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unsigned long sfcount[2];
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union {
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struct ip_mc_list *next;
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struct ip_mc_list __rcu *next_rcu;
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};
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struct ip_mc_list __rcu *next_hash;
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struct timer_list timer;
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int users;
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refcount_t refcnt;
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spinlock_t lock;
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char tm_running;
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char reporter;
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char unsolicit_count;
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char loaded;
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unsigned char gsquery; /* check source marks? */
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unsigned char crcount;
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struct rcu_head rcu;
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};
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/* V3 exponential field decoding */
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#define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
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#define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
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((value) < (thresh) ? (value) : \
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((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
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(IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
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#define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
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#define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
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extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
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extern int igmp_rcv(struct sk_buff *);
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extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
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extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
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unsigned int mode);
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extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
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extern void ip_mc_drop_socket(struct sock *sk);
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extern int ip_mc_source(int add, int omode, struct sock *sk,
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struct ip_mreq_source *mreqs, int ifindex);
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extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
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extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
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struct ip_msfilter __user *optval, int __user *optlen);
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extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
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struct group_filter __user *optval, int __user *optlen);
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extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
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int dif, int sdif);
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extern void ip_mc_init_dev(struct in_device *);
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extern void ip_mc_destroy_dev(struct in_device *);
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extern void ip_mc_up(struct in_device *);
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extern void ip_mc_down(struct in_device *);
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extern void ip_mc_unmap(struct in_device *);
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extern void ip_mc_remap(struct in_device *);
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extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
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extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
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int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed);
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#endif
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