From f68b2e05f326971cd76c65aa91a1a41771dd7485 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 4 Sep 2009 18:21:00 -0400 Subject: [PATCH] sctp: Fix SCTP_MAXSEG socket option to comply to spec. We had a bug that we never stored the user-defined value for MAXSEG when setting the value on an association. Thus future PMTU events ended up re-writing the frag point and increasing it past user limit. Additionally, when setting the option on the socket/endpoint, we effect all current associations, which is against spec. Now, we store the user 'maxseg' value along with the computed 'frag_point'. We inherit 'maxseg' from the socket at association creation and use it as an upper limit for 'frag_point' when its set. Signed-off-by: Vlad Yasevich --- include/net/sctp/sctp.h | 7 ++++--- include/net/sctp/structs.h | 1 + net/sctp/associola.c | 6 +++--- net/sctp/socket.c | 11 +++-------- 4 files changed, 11 insertions(+), 14 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index d16a304cbed..8a6d5297de1 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -486,15 +486,16 @@ static inline __s32 sctp_jitter(__u32 rto) } /* Break down data chunks at this point. */ -static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu) +static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu) { + struct sctp_sock *sp = sctp_sk(asoc->base.sk); int frag = pmtu; frag -= sp->pf->af->net_header_len; frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); - if (sp->user_frag) - frag = min_t(int, frag, sp->user_frag); + if (asoc->user_frag) + frag = min_t(int, frag, asoc->user_frag); frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN); diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index df4c6321996..b10612810f5 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1763,6 +1763,7 @@ struct sctp_association { /* The message size at which SCTP fragmentation will occur. */ __u32 frag_point; + __u32 user_frag; /* Counter used to count INIT errors. */ int init_err_counter; diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 39c3821b7d3..1f05b942564 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -112,6 +112,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000) * 1000; asoc->frag_point = 0; + asoc->user_frag = sp->user_frag; /* Set the association max_retrans and RTO values from the * socket values. @@ -674,7 +675,7 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, "%d\n", asoc, asoc->pathmtu); peer->pmtu_pending = 0; - asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu); + asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); /* The asoc->peer.port might not be meaningful yet, but * initialize the packet structure anyway. @@ -1330,9 +1331,8 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc) } if (pmtu) { - struct sctp_sock *sp = sctp_sk(asoc->base.sk); asoc->pathmtu = pmtu; - asoc->frag_point = sctp_frag_point(sp, pmtu); + asoc->frag_point = sctp_frag_point(asoc, pmtu); } SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n", diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 95a5623d79a..89af37a6c87 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2243,7 +2243,7 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params, sctp_assoc_sync_pmtu(asoc); } else if (asoc) { asoc->pathmtu = params->spp_pathmtu; - sctp_frag_point(sp, params->spp_pathmtu); + sctp_frag_point(asoc, params->spp_pathmtu); } else { sp->pathmtu = params->spp_pathmtu; } @@ -2880,15 +2880,10 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, int optl val -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); } - - asoc->frag_point = val; + asoc->user_frag = val; + asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); } else { sp->user_frag = val; - - /* Update the frag_point of the existing associations. */ - list_for_each_entry(asoc, &(sp->ep->asocs), asocs) { - asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu); - } } return 0; -- 2.20.1