git: 81a1bfac592b - stable/13 - sctp: improve sctp_pathmtu_adjustment()
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Date: Tue, 22 Feb 2022 23:59:36 UTC
The branch stable/13 has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=81a1bfac592bc2ca29788a5b8cc6e5ff1e86fb9d commit 81a1bfac592bc2ca29788a5b8cc6e5ff1e86fb9d Author: Michael Tuexen <tuexen@FreeBSD.org> AuthorDate: 2021-12-30 14:16:05 +0000 Commit: Michael Tuexen <tuexen@FreeBSD.org> CommitDate: 2022-02-22 23:58:06 +0000 sctp: improve sctp_pathmtu_adjustment() Allow the resending of DATA chunks to be controlled by the caller, which allows retiring sctp_mtu_size_reset() in a separate commit. Also improve the computaion of the overhead and use 32-bit integers consistently. Thanks to Timo Voelker for pointing me to the code. (cherry picked from commit 2de2ae331be2504d1038b2124e7d44f23aa70405) --- sys/netinet/sctp_input.c | 6 ++--- sys/netinet/sctp_pcb.c | 2 +- sys/netinet/sctp_usrreq.c | 62 ++++++++++++++++++++++++++++----------------- sys/netinet/sctp_var.h | 2 +- sys/netinet6/sctp6_usrreq.c | 2 +- 5 files changed, 45 insertions(+), 29 deletions(-) diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c index f707bc1de11e..f4a698b3a775 100644 --- a/sys/netinet/sctp_input.c +++ b/sys/netinet/sctp_input.c @@ -5291,7 +5291,7 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt /* UDP encapsulation turned on. */ net->mtu -= sizeof(struct udphdr); if (stcb->asoc.smallest_mtu > net->mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } } else if (port == 0) { /* UDP encapsulation turned off. */ @@ -5331,7 +5331,7 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt /* UDP encapsulation turned on. */ net->mtu -= sizeof(struct udphdr); if (stcb->asoc.smallest_mtu > net->mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } } else if (port == 0) { /* UDP encapsulation turned off. */ @@ -5426,7 +5426,7 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt /* UDP encapsulation turned on. */ net->mtu -= sizeof(struct udphdr); if (stcb->asoc.smallest_mtu > net->mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } } else if (port == 0) { /* UDP encapsulation turned off. */ diff --git a/sys/netinet/sctp_pcb.c b/sys/netinet/sctp_pcb.c index 176a35220688..23bef0ebaf05 100644 --- a/sys/netinet/sctp_pcb.c +++ b/sys/netinet/sctp_pcb.c @@ -4026,7 +4026,7 @@ sctp_add_remote_addr(struct sctp_tcb *stcb, struct sockaddr *newaddr, stcb->asoc.smallest_mtu = net->mtu; } if (stcb->asoc.smallest_mtu > net->mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } #ifdef INET6 if (newaddr->sa_family == AF_INET6) { diff --git a/sys/netinet/sctp_usrreq.c b/sys/netinet/sctp_usrreq.c index a49bebc7edec..a9ca2d063202 100644 --- a/sys/netinet/sctp_usrreq.c +++ b/sys/netinet/sctp_usrreq.c @@ -104,35 +104,51 @@ VNET_SYSUNINIT(sctp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, sctp_finish, NULL); #endif void -sctp_pathmtu_adjustment(struct sctp_tcb *stcb, uint16_t nxtsz) +sctp_pathmtu_adjustment(struct sctp_tcb *stcb, uint32_t mtu, bool resend) { + struct sctp_association *asoc; struct sctp_tmit_chunk *chk; - uint16_t overhead; - - /* Adjust that too */ - stcb->asoc.smallest_mtu = nxtsz; - /* now off to subtract IP_DF flag if needed */ - overhead = IP_HDR_SIZE + sizeof(struct sctphdr); - if (sctp_auth_is_required_chunk(SCTP_DATA, stcb->asoc.peer_auth_chunks)) { - overhead += sctp_get_auth_chunk_len(stcb->asoc.peer_hmac_id); + uint32_t overhead; + + asoc = &stcb->asoc; + KASSERT(mtu < asoc->smallest_mtu, + ("Currently only reducing association MTU %u supported (MTU %u)", + asoc->smallest_mtu, mtu)); + asoc->smallest_mtu = mtu; + if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_BOUND_V6) { + overhead = SCTP_MIN_OVERHEAD; + } else { + overhead = SCTP_MIN_V4_OVERHEAD; + } + if (asoc->idata_supported) { + if (sctp_auth_is_required_chunk(SCTP_IDATA, asoc->peer_auth_chunks)) { + overhead += sctp_get_auth_chunk_len(asoc->peer_hmac_id); + } + } else { + if (sctp_auth_is_required_chunk(SCTP_DATA, asoc->peer_auth_chunks)) { + overhead += sctp_get_auth_chunk_len(asoc->peer_hmac_id); + } } - TAILQ_FOREACH(chk, &stcb->asoc.send_queue, sctp_next) { - if ((chk->send_size + overhead) > nxtsz) { + KASSERT(overhead % 4 == 0, + ("overhead (%u) not a multiple of 4", overhead)); + TAILQ_FOREACH(chk, &asoc->send_queue, sctp_next) { + if (((uint32_t)chk->send_size + overhead) > mtu) { chk->flags |= CHUNK_FLAGS_FRAGMENT_OK; } } - TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) { - if ((chk->send_size + overhead) > nxtsz) { - /* - * For this guy we also mark for immediate resend - * since we sent to big of chunk - */ + TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) { + if (((uint32_t)chk->send_size + overhead) > mtu) { chk->flags |= CHUNK_FLAGS_FRAGMENT_OK; - if (chk->sent < SCTP_DATAGRAM_RESEND) { + if (resend && chk->sent < SCTP_DATAGRAM_RESEND) { + /* + * If requested, mark the chunk for + * immediate resend, since we sent it being + * too big. + */ sctp_flight_size_decrease(chk); sctp_total_flight_decrease(stcb, chk); chk->sent = SCTP_DATAGRAM_RESEND; - sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt); + sctp_ucount_incr(asoc->sent_queue_retran_cnt); chk->rec.data.doing_fast_retransmit = 0; if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) { sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_PMTU, @@ -141,7 +157,7 @@ sctp_pathmtu_adjustment(struct sctp_tcb *stcb, uint16_t nxtsz) (uint32_t)(uintptr_t)chk->whoTo, chk->rec.data.tsn); } - /* Clear any time so NO RTT is being done */ + /* Clear any time, so NO RTT is being done. */ if (chk->do_rtt == 1) { chk->do_rtt = 0; chk->whoTo->rto_needed = 1; @@ -229,7 +245,7 @@ sctp_notify(struct sctp_inpcb *inp, } /* Update the association MTU */ if (stcb->asoc.smallest_mtu > next_mtu) { - sctp_pathmtu_adjustment(stcb, next_mtu); + sctp_pathmtu_adjustment(stcb, next_mtu, true); } /* Finally, start the PMTU timer if it was running before. */ if (timer_stopped) { @@ -5363,7 +5379,7 @@ sctp_setopt(struct socket *so, int optname, void *optval, size_t optsize, break; } if (net->mtu < stcb->asoc.smallest_mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } } } @@ -5507,7 +5523,7 @@ sctp_setopt(struct socket *so, int optname, void *optval, size_t optsize, break; } if (net->mtu < stcb->asoc.smallest_mtu) { - sctp_pathmtu_adjustment(stcb, net->mtu); + sctp_pathmtu_adjustment(stcb, net->mtu, true); } } } diff --git a/sys/netinet/sctp_var.h b/sys/netinet/sctp_var.h index ed01de7d7014..a18dbb5e66e2 100644 --- a/sys/netinet/sctp_var.h +++ b/sys/netinet/sctp_var.h @@ -328,7 +328,7 @@ int sctp_ctloutput(struct socket *, struct sockopt *); void sctp_input_with_port(struct mbuf *, int, uint16_t); int sctp_input(struct mbuf **, int *, int); #endif -void sctp_pathmtu_adjustment(struct sctp_tcb *, uint16_t); +void sctp_pathmtu_adjustment(struct sctp_tcb *, uint32_t, bool); void sctp_drain(void); void sctp_init(void); void diff --git a/sys/netinet6/sctp6_usrreq.c b/sys/netinet6/sctp6_usrreq.c index 516107caf408..361bc4a18a2f 100644 --- a/sys/netinet6/sctp6_usrreq.c +++ b/sys/netinet6/sctp6_usrreq.c @@ -233,7 +233,7 @@ sctp6_notify(struct sctp_inpcb *inp, } /* Update the association MTU */ if (stcb->asoc.smallest_mtu > next_mtu) { - sctp_pathmtu_adjustment(stcb, next_mtu); + sctp_pathmtu_adjustment(stcb, next_mtu, true); } /* Finally, start the PMTU timer if it was running before. */ if (timer_stopped) {