From c45698f89626177f8c51409142cbe9c5bbed4af7 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:50 -0300 Subject: [PATCH 01/13] sctp: remove old and unused SCTP_MIN_PMTU This value is not used anywhere in the code. In essence it is a duplicate of SCTP_DEFAULT_MINSEGMENT, which is used by the stack. SCTP_MIN_PMTU value makes more sense, but we should not change to it now as it would risk breaking applications. So this patch removes SCTP_MIN_PMTU and adjust the comment above it. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/constants.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h index 20ff237c5eb2f..86f034b524d46 100644 --- a/include/net/sctp/constants.h +++ b/include/net/sctp/constants.h @@ -254,11 +254,10 @@ enum { SCTP_ARBITRARY_COOKIE_ECHO_LEN = 200 }; #define SCTP_TSN_MAP_SIZE 4096 /* We will not record more than this many duplicate TSNs between two - * SACKs. The minimum PMTU is 576. Remove all the headers and there - * is enough room for 131 duplicate reports. Round down to the + * SACKs. The minimum PMTU is 512. Remove all the headers and there + * is enough room for 117 duplicate reports. Round down to the * nearest power of 2. */ -enum { SCTP_MIN_PMTU = 576 }; enum { SCTP_MAX_DUP_TSNS = 16 }; enum { SCTP_MAX_GABS = 16 }; From 800e00c12733fe2ed565206dcdb515fa2f705b9f Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:51 -0300 Subject: [PATCH 02/13] sctp: move transport pathmtu calc away of sctp_assoc_add_peer There was only one case that sctp_assoc_add_peer couldn't handle, which is when SPP_PMTUD_DISABLE is set and pathmtu not initialized. So add this situation to sctp_transport_route and reuse what was already in there. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/associola.c | 9 +-------- net/sctp/transport.c | 8 ++++++-- 2 files changed, 7 insertions(+), 10 deletions(-) diff --git a/net/sctp/associola.c b/net/sctp/associola.c index a8f3b088fcb2a..b3aa95222bd52 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -652,15 +652,8 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, */ peer->param_flags = asoc->param_flags; - sctp_transport_route(peer, NULL, sp); - /* Initialize the pmtu of the transport. */ - if (peer->param_flags & SPP_PMTUD_DISABLE) { - if (asoc->pathmtu) - peer->pathmtu = asoc->pathmtu; - else - peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT; - } + sctp_transport_route(peer, NULL, sp); /* If this is the first transport addr on this association, * initialize the association PMTU to the peer's PMTU. diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 47f82bd794d91..c5fc3aed08a18 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -307,11 +307,15 @@ void sctp_transport_route(struct sctp_transport *transport, * association's active path for getsockname(). */ if (asoc && (!asoc->peer.primary_path || - (transport == asoc->peer.active_path))) + (transport == asoc->peer.active_path))) opt->pf->to_sk_saddr(&transport->saddr, asoc->base.sk); - } else + } else if ((transport->param_flags & SPP_PMTUD_DISABLE) && + asoc && asoc->pathmtu) { + transport->pathmtu = asoc->pathmtu; + } else { transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT; + } } /* Hold a reference to a transport. */ From c88da20f95ad0bfa49e3e9035c26aaac0b05d11d Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:52 -0300 Subject: [PATCH 03/13] sctp: remove an if() that is always true As noticed by Xin Long, the if() here is always true as PMTU can never be 0. Reported-by: Xin Long Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/associola.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/sctp/associola.c b/net/sctp/associola.c index b3aa95222bd52..c5ed09cfa8423 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -1397,10 +1397,8 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc) pmtu = t->pathmtu; } - if (pmtu) { - asoc->pathmtu = pmtu; - asoc->frag_point = sctp_frag_point(asoc, pmtu); - } + asoc->pathmtu = pmtu; + asoc->frag_point = sctp_frag_point(asoc, pmtu); pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, asoc->pathmtu, asoc->frag_point); From c4b2893dae6427ce1e528033383c94cbf81e80d8 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:53 -0300 Subject: [PATCH 04/13] sctp: introduce sctp_assoc_set_pmtu All changes to asoc PMTU should now go through this wrapper, making it easier to track them and to do other actions upon it. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/structs.h | 1 + net/sctp/associola.c | 21 +++++++++++++-------- net/sctp/socket.c | 2 +- 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 05594b248e527..c5e244be8f1ea 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -2097,6 +2097,7 @@ int sctp_assoc_update(struct sctp_association *old, __u32 sctp_association_get_next_tsn(struct sctp_association *); +void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu); void sctp_assoc_sync_pmtu(struct sctp_association *asoc); void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); diff --git a/net/sctp/associola.c b/net/sctp/associola.c index c5ed09cfa8423..85b362324084e 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -660,13 +660,9 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, * If not and the current association PMTU is higher than the new * peer's PMTU, reset the association PMTU to the new peer's PMTU. */ - if (asoc->pathmtu) - asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu); - else - asoc->pathmtu = peer->pathmtu; - - pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc, - asoc->pathmtu); + sctp_assoc_set_pmtu(asoc, asoc->pathmtu ? + min_t(int, peer->pathmtu, asoc->pathmtu) : + peer->pathmtu); peer->pmtu_pending = 0; @@ -1374,6 +1370,15 @@ sctp_assoc_choose_alter_transport(struct sctp_association *asoc, } } +void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu) +{ + if (asoc->pathmtu != pmtu) + asoc->pathmtu = pmtu; + + pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, + asoc->pathmtu, asoc->frag_point); +} + /* Update the association's pmtu and frag_point by going through all the * transports. This routine is called when a transport's PMTU has changed. */ @@ -1397,7 +1402,7 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc) pmtu = t->pathmtu; } - asoc->pathmtu = pmtu; + sctp_assoc_set_pmtu(asoc, pmtu); asoc->frag_point = sctp_frag_point(asoc, pmtu); pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 80835ac26d2c3..eeec81d5c485b 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2539,7 +2539,7 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params, trans->pathmtu = params->spp_pathmtu; sctp_assoc_sync_pmtu(asoc); } else if (asoc) { - asoc->pathmtu = params->spp_pathmtu; + sctp_assoc_set_pmtu(asoc, params->spp_pathmtu); } else { sp->pathmtu = params->spp_pathmtu; } From feddd6c1af30ab11d73ce0e4e76b40dfc899dbda Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:54 -0300 Subject: [PATCH 05/13] sctp: introduce sctp_mtu_payload When given a MTU, this function calculates how much payload we can carry on it. Without a MTU, it calculates the amount of header overhead we have. So that when we have extra overhead, like the one added for IP options on SELinux patches, it is easier to handle it. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 19 +++++++++++++++++++ net/sctp/output.c | 25 ++++++++++--------------- net/sctp/socket.c | 7 ++----- 3 files changed, 31 insertions(+), 20 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 28b996d634907..0b98e4683f108 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -607,6 +607,25 @@ static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport * return t->dst; } +/* Calculate max payload size given a MTU, or the total overhead if + * given MTU is zero + */ +static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, + __u32 mtu, __u32 extra) +{ + __u32 overhead = sizeof(struct sctphdr) + extra; + + if (sp) + overhead += sp->pf->af->net_header_len; + else + overhead += sizeof(struct ipv6hdr); + + if (WARN_ON_ONCE(mtu && mtu <= overhead)) + mtu = overhead; + + return mtu ? mtu - overhead : overhead; +} + static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) { __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)), diff --git a/net/sctp/output.c b/net/sctp/output.c index 690d8557bb7bf..bf4226c3cc1de 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -90,8 +90,8 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, { struct sctp_transport *tp = packet->transport; struct sctp_association *asoc = tp->asoc; + struct sctp_sock *sp = NULL; struct sock *sk; - size_t overhead = sizeof(struct ipv6hdr) + sizeof(struct sctphdr); pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); packet->vtag = vtag; @@ -102,25 +102,20 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, /* set packet max_size with pathmtu, then calculate overhead */ packet->max_size = tp->pathmtu; + if (asoc) { - struct sctp_sock *sp = sctp_sk(asoc->base.sk); - struct sctp_af *af = sp->pf->af; - - overhead = af->net_header_len + - af->ip_options_len(asoc->base.sk); - overhead += sizeof(struct sctphdr); - packet->overhead = overhead; - packet->size = overhead; - } else { - packet->overhead = overhead; - packet->size = overhead; - return; + sk = asoc->base.sk; + sp = sctp_sk(sk); } + packet->overhead = sctp_mtu_payload(sp, 0, 0); + packet->size = packet->overhead; + + if (!asoc) + return; /* update dst or transport pathmtu if in need */ - sk = asoc->base.sk; if (!sctp_transport_dst_check(tp)) { - sctp_transport_route(tp, NULL, sctp_sk(sk)); + sctp_transport_route(tp, NULL, sp); if (asoc->param_flags & SPP_PMTUD_ENABLE) sctp_assoc_sync_pmtu(asoc); } else if (!sctp_transport_pmtu_check(tp)) { diff --git a/net/sctp/socket.c b/net/sctp/socket.c index eeec81d5c485b..b9d14f57146b8 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3234,11 +3234,8 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned if (val) { int min_len, max_len; - min_len = SCTP_DEFAULT_MINSEGMENT - af->net_header_len; - min_len -= af->ip_options_len(sk); - min_len -= sizeof(struct sctphdr) + - sizeof(struct sctp_data_chunk); - + min_len = sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, + sizeof(struct sctp_data_chunk)); max_len = SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_data_chunk); if (val < min_len || val > max_len) From 2f5e3c9df6938b823664869ec87af3da8df272f6 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:55 -0300 Subject: [PATCH 06/13] sctp: introduce sctp_assoc_update_frag_point and avoid the open-coded versions of it. Now sctp_datamsg_from_user can just re-use asoc->frag_point as it will always be updated. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 20 -------------------- include/net/sctp/structs.h | 1 + net/sctp/associola.c | 24 +++++++++++++++++------- net/sctp/chunk.c | 12 +----------- net/sctp/socket.c | 2 +- 5 files changed, 20 insertions(+), 39 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 0b98e4683f108..350c65620a4eb 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -428,26 +428,6 @@ static inline int sctp_list_single_entry(struct list_head *head) return (head->next != head) && (head->next == head->prev); } -/* Break down data chunks at this point. */ -static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu) -{ - struct sctp_sock *sp = sctp_sk(asoc->base.sk); - struct sctp_af *af = sp->pf->af; - int frag = pmtu; - - frag -= af->ip_options_len(asoc->base.sk); - frag -= af->net_header_len; - frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream); - - if (asoc->user_frag) - frag = min_t(int, frag, asoc->user_frag); - - frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN - - sctp_datachk_len(&asoc->stream))); - - return frag; -} - static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc) { sctp_assoc_sync_pmtu(asoc); diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index c5e244be8f1ea..ebf809eed33ad 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -2097,6 +2097,7 @@ int sctp_assoc_update(struct sctp_association *old, __u32 sctp_association_get_next_tsn(struct sctp_association *); +void sctp_assoc_update_frag_point(struct sctp_association *asoc); void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu); void sctp_assoc_sync_pmtu(struct sctp_association *asoc); void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 85b362324084e..a29025418b960 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -666,8 +666,6 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, peer->pmtu_pending = 0; - asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); - /* The asoc->peer.port might not be meaningful yet, but * initialize the packet structure anyway. */ @@ -1370,10 +1368,26 @@ sctp_assoc_choose_alter_transport(struct sctp_association *asoc, } } +void sctp_assoc_update_frag_point(struct sctp_association *asoc) +{ + int frag = sctp_mtu_payload(sctp_sk(asoc->base.sk), asoc->pathmtu, + sctp_datachk_len(&asoc->stream)); + + if (asoc->user_frag) + frag = min_t(int, frag, asoc->user_frag); + + frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN - + sctp_datachk_len(&asoc->stream)); + + asoc->frag_point = SCTP_TRUNC4(frag); +} + void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu) { - if (asoc->pathmtu != pmtu) + if (asoc->pathmtu != pmtu) { asoc->pathmtu = pmtu; + sctp_assoc_update_frag_point(asoc); + } pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, asoc->pathmtu, asoc->frag_point); @@ -1403,10 +1417,6 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc) } sctp_assoc_set_pmtu(asoc, pmtu); - asoc->frag_point = sctp_frag_point(asoc, pmtu); - - pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, - asoc->pathmtu, asoc->frag_point); } /* Should we send a SACK to update our peer? */ diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index be296d633e951..79daa98208c39 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -172,8 +172,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, struct list_head *pos, *temp; struct sctp_chunk *chunk; struct sctp_datamsg *msg; - struct sctp_sock *sp; - struct sctp_af *af; int err; msg = sctp_datamsg_new(GFP_KERNEL); @@ -192,12 +190,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, /* This is the biggest possible DATA chunk that can fit into * the packet */ - sp = sctp_sk(asoc->base.sk); - af = sp->pf->af; - max_data = asoc->pathmtu - af->net_header_len - - sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream) - - af->ip_options_len(asoc->base.sk); - max_data = SCTP_TRUNC4(max_data); + max_data = asoc->frag_point; /* If the the peer requested that we authenticate DATA chunks * we need to account for bundling of the AUTH chunks along with @@ -222,9 +215,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, } } - /* Check what's our max considering the above */ - max_data = min_t(size_t, max_data, asoc->frag_point); - /* Set first_len and then account for possible bundles on first frag */ first_len = max_data; diff --git a/net/sctp/socket.c b/net/sctp/socket.c index b9d14f57146b8..21bf457be3ea3 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3251,7 +3251,7 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned sctp_datachk_len(&asoc->stream); } asoc->user_frag = val; - asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); + sctp_assoc_update_frag_point(asoc); } else { if (params.assoc_id && sctp_style(sk, UDP)) return -EINVAL; From 2521680e1830c21033efe48322829044c6e6b32b Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:56 -0300 Subject: [PATCH 07/13] sctp: remove sctp_assoc_pending_pmtu No need for this helper. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 6 ------ net/sctp/socket.c | 6 ++++-- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 350c65620a4eb..e327acad8e7d0 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -428,12 +428,6 @@ static inline int sctp_list_single_entry(struct list_head *head) return (head->next != head) && (head->next == head->prev); } -static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc) -{ - sctp_assoc_sync_pmtu(asoc); - asoc->pmtu_pending = 0; -} - static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) { return !list_empty(&chunk->list); diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 21bf457be3ea3..a93b60a28cc5f 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1918,8 +1918,10 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc, goto err; } - if (asoc->pmtu_pending) - sctp_assoc_pending_pmtu(asoc); + if (asoc->pmtu_pending) { + sctp_assoc_sync_pmtu(asoc); + asoc->pmtu_pending = 0; + } if (sctp_wspace(asoc) < msg_len) sctp_prsctp_prune(asoc, sinfo, msg_len - sctp_wspace(asoc)); From 6ff0f871c20ec1769a481edca86f23c76b2b06d3 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:57 -0300 Subject: [PATCH 08/13] sctp: introduce sctp_dst_mtu Which makes sure that the MTU respects the minimum value of SCTP_DEFAULT_MINSEGMENT and that it is correctly aligned. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 9 +++++++-- net/sctp/associola.c | 6 ++---- net/sctp/transport.c | 6 +++--- 3 files changed, 12 insertions(+), 9 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index e327acad8e7d0..4965cbfa7d92c 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -600,10 +600,15 @@ static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp, return mtu ? mtu - overhead : overhead; } +static inline __u32 sctp_dst_mtu(const struct dst_entry *dst) +{ + return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst), + SCTP_DEFAULT_MINSEGMENT)); +} + static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) { - __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)), - SCTP_DEFAULT_MINSEGMENT); + __u32 pmtu = sctp_dst_mtu(t->dst); if (t->pathmtu == pmtu) return true; diff --git a/net/sctp/associola.c b/net/sctp/associola.c index a29025418b960..039fdb862b179 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -1405,11 +1405,9 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc) return; /* Get the lowest pmtu of all the transports. */ - list_for_each_entry(t, &asoc->peer.transport_addr_list, - transports) { + list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { if (t->pmtu_pending && t->dst) { - sctp_transport_update_pmtu( - t, SCTP_TRUNC4(dst_mtu(t->dst))); + sctp_transport_update_pmtu(t, sctp_dst_mtu(t->dst)); t->pmtu_pending = 0; } if (!pmtu || (t->pathmtu < pmtu)) diff --git a/net/sctp/transport.c b/net/sctp/transport.c index c5fc3aed08a18..ed73a9d91b83e 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -242,9 +242,9 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk) &transport->fl, sk); } - if (transport->dst) { - transport->pathmtu = SCTP_TRUNC4(dst_mtu(transport->dst)); - } else + if (transport->dst) + transport->pathmtu = sctp_dst_mtu(transport->dst); + else transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT; } From 22d7be267eaa8114dcc28d66c1c347f667d7878a Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:58 -0300 Subject: [PATCH 09/13] sctp: remove sctp_transport_pmtu_check We are now keeping the MTU information synced between asoc, transport and dst, which makes the check at sctp_packet_config() not needed anymore. As it was the sole caller to this function, lets remove it. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 12 ------------ net/sctp/output.c | 3 --- 2 files changed, 15 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 4965cbfa7d92c..f66d443500079 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -606,16 +606,4 @@ static inline __u32 sctp_dst_mtu(const struct dst_entry *dst) SCTP_DEFAULT_MINSEGMENT)); } -static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) -{ - __u32 pmtu = sctp_dst_mtu(t->dst); - - if (t->pathmtu == pmtu) - return true; - - t->pathmtu = pmtu; - - return false; -} - #endif /* __net_sctp_h__ */ diff --git a/net/sctp/output.c b/net/sctp/output.c index bf4226c3cc1de..e672dee302c70 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -118,9 +118,6 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, sctp_transport_route(tp, NULL, sp); if (asoc->param_flags & SPP_PMTUD_ENABLE) sctp_assoc_sync_pmtu(asoc); - } else if (!sctp_transport_pmtu_check(tp)) { - if (asoc->param_flags & SPP_PMTUD_ENABLE) - sctp_assoc_sync_pmtu(asoc); } /* If there a is a prepend chunk stick it on the list before From 6e91b578bf3f9e19c250835cba97a4be38ffcb31 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:58:59 -0300 Subject: [PATCH 10/13] sctp: re-use sctp_transport_pmtu in sctp_transport_route sctp_transport_route currently is very similar to sctp_transport_pmtu plus a few other bits. This patch reuses sctp_transport_pmtu in sctp_transport_route and removes the duplicated code. Also, as all calls to sctp_transport_route were forcing the dst release before calling it, let's just include such release too. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 6 ++---- net/sctp/transport.c | 35 +++++++++++++++++------------------ 2 files changed, 19 insertions(+), 22 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index a93b60a28cc5f..bb08d44b838bb 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -644,16 +644,15 @@ static int sctp_send_asconf_add_ip(struct sock *sk, list_for_each_entry(trans, &asoc->peer.transport_addr_list, transports) { - /* Clear the source and route cache */ - sctp_transport_dst_release(trans); trans->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); trans->ssthresh = asoc->peer.i.a_rwnd; trans->rto = asoc->rto_initial; sctp_max_rto(asoc, trans); trans->rtt = trans->srtt = trans->rttvar = 0; + /* Clear the source and route cache */ sctp_transport_route(trans, NULL, - sctp_sk(asoc->base.sk)); + sctp_sk(asoc->base.sk)); } } retval = sctp_send_asconf(asoc, chunk); @@ -896,7 +895,6 @@ static int sctp_send_asconf_del_ip(struct sock *sk, */ list_for_each_entry(transport, &asoc->peer.transport_addr_list, transports) { - sctp_transport_dst_release(transport); sctp_transport_route(transport, NULL, sctp_sk(asoc->base.sk)); } diff --git a/net/sctp/transport.c b/net/sctp/transport.c index ed73a9d91b83e..4a95e260b674b 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -242,6 +242,15 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk) &transport->fl, sk); } + if (transport->param_flags & SPP_PMTUD_DISABLE) { + struct sctp_association *asoc = transport->asoc; + + if (!transport->pathmtu && asoc && asoc->pathmtu) + transport->pathmtu = asoc->pathmtu; + if (transport->pathmtu) + return; + } + if (transport->dst) transport->pathmtu = sctp_dst_mtu(transport->dst); else @@ -290,6 +299,7 @@ void sctp_transport_route(struct sctp_transport *transport, struct sctp_association *asoc = transport->asoc; struct sctp_af *af = transport->af_specific; + sctp_transport_dst_release(transport); af->get_dst(transport, saddr, &transport->fl, sctp_opt2sk(opt)); if (saddr) @@ -297,25 +307,14 @@ void sctp_transport_route(struct sctp_transport *transport, else af->get_saddr(opt, transport, &transport->fl); - if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) { - return; - } - if (transport->dst) { - transport->pathmtu = SCTP_TRUNC4(dst_mtu(transport->dst)); + sctp_transport_pmtu(transport, sctp_opt2sk(opt)); - /* Initialize sk->sk_rcv_saddr, if the transport is the - * association's active path for getsockname(). - */ - if (asoc && (!asoc->peer.primary_path || - (transport == asoc->peer.active_path))) - opt->pf->to_sk_saddr(&transport->saddr, - asoc->base.sk); - } else if ((transport->param_flags & SPP_PMTUD_DISABLE) && - asoc && asoc->pathmtu) { - transport->pathmtu = asoc->pathmtu; - } else { - transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT; - } + /* Initialize sk->sk_rcv_saddr, if the transport is the + * association's active path for getsockname(). + */ + if (transport->dst && asoc && + (!asoc->peer.primary_path || transport == asoc->peer.active_path)) + opt->pf->to_sk_saddr(&transport->saddr, asoc->base.sk); } /* Hold a reference to a transport. */ From 63d01330aad9531a491db1bed5f15cc6b7fd1a78 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:59:00 -0300 Subject: [PATCH 11/13] sctp: honor PMTU_DISABLED when handling icmp sctp_sendmsg() could trigger PMTU updates even when PMTU_DISABLED was set, as pmtu_pending could be set unconditionally during icmp handling if the socket was in use by the application. This patch fixes it by checking for PMTU_DISABLED when handling such deferred updates. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index bb08d44b838bb..ad8965835d8d5 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1893,6 +1893,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc, struct sctp_sndrcvinfo *sinfo) { struct sock *sk = asoc->base.sk; + struct sctp_sock *sp = sctp_sk(sk); struct net *net = sock_net(sk); struct sctp_datamsg *datamsg; bool wait_connect = false; @@ -1911,13 +1912,14 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc, goto err; } - if (sctp_sk(sk)->disable_fragments && msg_len > asoc->frag_point) { + if (sp->disable_fragments && msg_len > asoc->frag_point) { err = -EMSGSIZE; goto err; } if (asoc->pmtu_pending) { - sctp_assoc_sync_pmtu(asoc); + if (sp->param_flags & SPP_PMTUD_ENABLE) + sctp_assoc_sync_pmtu(asoc); asoc->pmtu_pending = 0; } @@ -1936,7 +1938,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc, if (err) goto err; - if (sctp_sk(sk)->strm_interleave) { + if (sp->strm_interleave) { timeo = sock_sndtimeo(sk, 0); err = sctp_wait_for_connect(asoc, &timeo); if (err) From 439ef0309cf4b743d76edc2abeca72b27ee1d996 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:59:01 -0300 Subject: [PATCH 12/13] sctp: consider idata chunks when setting SCTP_MAXSEG When setting SCTP_MAXSEG sock option, it should consider which kind of data chunk is being used if the asoc is already available, so that the limit better reflect reality. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index ad8965835d8d5..2d35c8ea2470e 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3233,18 +3233,21 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned return -EINVAL; } + asoc = sctp_id2assoc(sk, params.assoc_id); + if (val) { int min_len, max_len; + __u16 datasize = asoc ? sctp_datachk_len(&asoc->stream) : + sizeof(struct sctp_data_chunk); min_len = sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, - sizeof(struct sctp_data_chunk)); - max_len = SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_data_chunk); + datasize); + max_len = SCTP_MAX_CHUNK_LEN - datasize; if (val < min_len || val > max_len) return -EINVAL; } - asoc = sctp_id2assoc(sk, params.assoc_id); if (asoc) { if (val == 0) { val = asoc->pathmtu - af->net_header_len; From 38687b56c51b535024d46d6b5375163a6a40a196 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 26 Apr 2018 16:59:02 -0300 Subject: [PATCH 13/13] sctp: allow unsetting sockopt MAXSEG RFC 6458 Section 8.1.16 says that setting MAXSEG as 0 means that the user is not limiting it, and not that it should set to the *current* maximum, as we are doing. This patch thus allow setting it as 0, effectively removing the user limit. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 2d35c8ea2470e..1b4593b842b00 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3211,7 +3211,6 @@ static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, unsign static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned int optlen) { struct sctp_sock *sp = sctp_sk(sk); - struct sctp_af *af = sp->pf->af; struct sctp_assoc_value params; struct sctp_association *asoc; int val; @@ -3249,12 +3248,6 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned } if (asoc) { - if (val == 0) { - val = asoc->pathmtu - af->net_header_len; - val -= af->ip_options_len(sk); - val -= sizeof(struct sctphdr) + - sctp_datachk_len(&asoc->stream); - } asoc->user_frag = val; sctp_assoc_update_frag_point(asoc); } else {