X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4bd07ac2140668789aa3ee8ec4dde4a3e0a3bba5..0a7de7458d150b5d4dffc935ba399be265ef0a1a:/bsd/netinet/tcp_sack.c diff --git a/bsd/netinet/tcp_sack.c b/bsd/netinet/tcp_sack.c index 5d0bf9130..a7c8e38d2 100644 --- a/bsd/netinet/tcp_sack.c +++ b/bsd/netinet/tcp_sack.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 2004-2015 Apple Inc. All rights reserved. + * Copyright (c) 2004-2016 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -59,7 +59,7 @@ * */ -#define _IP_VHL +#define _IP_VHL #include @@ -93,6 +93,7 @@ #include #include #include +#include #if TCPDEBUG #include #endif @@ -104,17 +105,14 @@ #include -int tcp_do_sack = 1; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, sack, CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_do_sack, 0, - "Enable/Disable TCP SACK support"); -static int tcp_sack_maxholes = 128; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, sack_maxholes, CTLFLAG_RW | CTLFLAG_LOCKED, - &tcp_sack_maxholes, 0, +SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack, CTLFLAG_RW | CTLFLAG_LOCKED, + int, tcp_do_sack, 1, "Enable/Disable TCP SACK support"); +SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack_maxholes, CTLFLAG_RW | CTLFLAG_LOCKED, + static int, tcp_sack_maxholes, 128, "Maximum number of TCP SACK holes allowed per connection"); -static int tcp_sack_globalmaxholes = 65536; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, sack_globalmaxholes, CTLFLAG_RW | CTLFLAG_LOCKED, - &tcp_sack_globalmaxholes, 0, +SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack_globalmaxholes, + CTLFLAG_RW | CTLFLAG_LOCKED, static int, tcp_sack_globalmaxholes, 65536, "Global maximum number of TCP SACK holes"); static SInt32 tcp_sack_globalholes = 0; @@ -137,7 +135,7 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, ignore_hw_duplicates, extern struct zone *sack_hole_zone; -#define TCP_VALIDATE_SACK_SEQ_NUMBERS(_tp_, _sb_, _ack_) \ +#define TCP_VALIDATE_SACK_SEQ_NUMBERS(_tp_, _sb_, _ack_) \ (SEQ_GT((_sb_)->end, (_sb_)->start) && \ SEQ_GT((_sb_)->start, (_tp_)->snd_una) && \ SEQ_GT((_sb_)->start, (_ack_)) && \ @@ -179,15 +177,17 @@ tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end) * Discard this SACK block. */ } else if (SEQ_LEQ(head_blk.start, end) && - SEQ_GEQ(head_blk.end, start)) { + SEQ_GEQ(head_blk.end, start)) { /* * Merge this SACK block into head_blk. * This SACK block itself will be discarded. */ - if (SEQ_GT(head_blk.start, start)) + if (SEQ_GT(head_blk.start, start)) { head_blk.start = start; - if (SEQ_LT(head_blk.end, end)) + } + if (SEQ_LT(head_blk.end, end)) { head_blk.end = end; + } } else { /* * Save this SACK block. @@ -213,15 +213,16 @@ tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end) * If the number of saved SACK blocks exceeds its limit, * discard the last SACK block. */ - if (num_saved >= MAX_SACK_BLKS) + if (num_saved >= MAX_SACK_BLKS) { num_saved--; + } } if (num_saved > 0) { /* * Copy the saved SACK blocks back. */ bcopy(saved_blks, &tp->sackblks[num_head], - sizeof(struct sackblk) * num_saved); + sizeof(struct sackblk) * num_saved); } /* Save the number of SACK blocks. */ @@ -231,12 +232,14 @@ tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end) * so that connection will generate more acks after recovery and * sender's cwnd will open. */ - if ((tp->t_flags & TF_STRETCHACK) != 0 && tp->rcv_numsacks > 0) + if ((tp->t_flags & TF_STRETCHACK) != 0 && tp->rcv_numsacks > 0) { tcp_reset_stretch_ack(tp); + } #if TRAFFIC_MGT - if (tp->acc_iaj > 0 && tp->rcv_numsacks > 0) + if (tp->acc_iaj > 0 && tp->rcv_numsacks > 0) { reset_acc_iaj(tp); + } #endif /* TRAFFIC_MGT */ } @@ -246,9 +249,8 @@ tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end) void tcp_clean_sackreport( struct tcpcb *tp) { - tp->rcv_numsacks = 0; - bzero(&tp->sackblks[0], sizeof (struct sackblk) * MAX_SACK_BLKS); + bzero(&tp->sackblks[0], sizeof(struct sackblk) * MAX_SACK_BLKS); } /* @@ -266,8 +268,9 @@ tcp_sackhole_alloc(struct tcpcb *tp, tcp_seq start, tcp_seq end) } hole = (struct sackhole *)zalloc(sack_hole_zone); - if (hole == NULL) + if (hole == NULL) { return NULL; + } hole->start = start; hole->end = end; @@ -296,26 +299,29 @@ tcp_sackhole_free(struct tcpcb *tp, struct sackhole *hole) */ static struct sackhole * tcp_sackhole_insert(struct tcpcb *tp, tcp_seq start, tcp_seq end, - struct sackhole *after) + struct sackhole *after) { struct sackhole *hole; /* Allocate a new SACK hole. */ hole = tcp_sackhole_alloc(tp, start, end); - if (hole == NULL) + if (hole == NULL) { return NULL; + } hole->rxmit_start = tcp_now; /* Insert the new SACK hole into scoreboard */ - if (after != NULL) + if (after != NULL) { TAILQ_INSERT_AFTER(&tp->snd_holes, after, hole, scblink); - else + } else { TAILQ_INSERT_TAIL(&tp->snd_holes, hole, scblink); + } /* Update SACK hint. */ - if (tp->sackhint.nexthole == NULL) + if (tp->sackhint.nexthole == NULL) { tp->sackhint.nexthole = hole; + } - return(hole); + return hole; } /* @@ -325,8 +331,9 @@ static void tcp_sackhole_remove(struct tcpcb *tp, struct sackhole *hole) { /* Update SACK hint. */ - if (tp->sackhint.nexthole == hole) + if (tp->sackhint.nexthole == hole) { tp->sackhint.nexthole = TAILQ_NEXT(hole, scblink); + } /* Remove this SACK hole. */ TAILQ_REMOVE(&tp->snd_holes, hole, scblink); @@ -350,15 +357,17 @@ tcp_sack_detect_reordering(struct tcpcb *tp, struct sackhole *s, * If the SACK hole is past snd_fack, this is from new SACK * information, so we can ignore it. */ - if (SEQ_GT(s->end, snd_fack)) + if (SEQ_GT(s->end, snd_fack)) { return; + } /* - * If there has been a retransmit timeout, then the timestamp on + * If there has been a retransmit timeout, then the timestamp on * the SACK segment will be newer. This might lead to a * false-positive. Avoid re-ordering detection in this case. */ - if (tp->t_rxtshift > 0) + if (tp->t_rxtshift > 0) { return; + } /* * Detect reordering from SACK information by checking @@ -379,12 +388,23 @@ tcp_sack_detect_reordering(struct tcpcb *tp, struct sackhole *s, tcpstat.tcps_reordered_pkts++; tp->t_reordered_pkts++; + /* + * If reordering is seen on a connection wth ECN enabled, + * increment the heuristic + */ + if (TCP_ECN_ENABLED(tp)) { + INP_INC_IFNET_STAT(tp->t_inpcb, ecn_fallback_reorder); + tcpstat.tcps_ecn_fallback_reorder++; + tcp_heuristic_ecn_aggressive(tp); + } + VERIFY(SEQ_GEQ(snd_fack, s->rxmit)); if (s->rxmit_start > 0) { rext = timer_diff(tcp_now, 0, s->rxmit_start, 0); - if (rext < 0) + if (rext < 0) { return; + } /* * We take the maximum reorder window to schedule @@ -412,8 +432,8 @@ tcp_sack_detect_reordering(struct tcpcb *tp, struct sackhole *s, * the sequence space). */ void -tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, - u_int32_t *newbytes_acked) +tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, + u_int32_t *newbytes_acked) { struct sackhole *cur, *temp; struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1], *sblkp; @@ -438,16 +458,18 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, &sack, sizeof(sack)); sack.start = ntohl(sack.start); sack.end = ntohl(sack.end); - if (TCP_VALIDATE_SACK_SEQ_NUMBERS(tp, &sack, th_ack)) + if (TCP_VALIDATE_SACK_SEQ_NUMBERS(tp, &sack, th_ack)) { sack_blocks[num_sack_blks++] = sack; + } } /* * Return if SND.UNA is not advanced and no valid SACK block * is received. */ - if (num_sack_blks == 0) + if (num_sack_blks == 0) { return; + } VERIFY(num_sack_blks <= (TCP_MAX_SACK + 1)); /* @@ -487,7 +509,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, * the highest three or four SACK blocks with ack number advancing * are received. */ - sblkp = &sack_blocks[num_sack_blks - 1]; /* Last SACK block */ + sblkp = &sack_blocks[num_sack_blks - 1]; /* Last SACK block */ if (SEQ_LT(tp->snd_fack, sblkp->start)) { /* * The highest SACK block is beyond fack. @@ -496,7 +518,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, * beyond the current fack, they will be inserted by * way of hole splitting in the while-loop below. */ - temp = tcp_sackhole_insert(tp, tp->snd_fack,sblkp->start,NULL); + temp = tcp_sackhole_insert(tp, tp->snd_fack, sblkp->start, NULL); if (temp != NULL) { tp->snd_fack = sblkp->end; *newbytes_acked += (sblkp->end - sblkp->start); @@ -504,18 +526,19 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, /* Go to the previous sack block. */ sblkp--; } else { - /* - * We failed to add a new hole based on the current - * sack block. Skip over all the sack blocks that + /* + * We failed to add a new hole based on the current + * sack block. Skip over all the sack blocks that * fall completely to the right of snd_fack and proceed * to trim the scoreboard based on the remaining sack - * blocks. This also trims the scoreboard for th_ack + * blocks. This also trims the scoreboard for th_ack * (which is sack_blocks[0]). */ - while (sblkp >= sack_blocks && - SEQ_LT(tp->snd_fack, sblkp->start)) + while (sblkp >= sack_blocks && + SEQ_LT(tp->snd_fack, sblkp->start)) { sblkp--; - if (sblkp >= sack_blocks && + } + if (sblkp >= sack_blocks && SEQ_LT(tp->snd_fack, sblkp->end)) { *newbytes_acked += (sblkp->end - tp->snd_fack); tp->snd_fack = sblkp->end; @@ -532,7 +555,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, * Since the incoming sack blocks are sorted, we can process them * making one sweep of the scoreboard. */ - while (sblkp >= sack_blocks && cur != NULL) { + while (sblkp >= sack_blocks && cur != NULL) { if (SEQ_GEQ(sblkp->start, cur->end)) { /* * SACKs data beyond the current hole. @@ -597,12 +620,12 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, if (SEQ_GT(cur->rxmit, temp->rxmit)) { temp->rxmit = cur->rxmit; tp->sackhint.sack_bytes_rexmit - += (temp->rxmit - - temp->start); + += (temp->rxmit + - temp->start); } cur->end = sblkp->start; cur->rxmit = SEQ_MIN(cur->rxmit, - cur->end); + cur->end); /* * Reset the rxmit_start to that of * the current hole as that will @@ -619,10 +642,11 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, * we're done with the sack block or the sack hole. * Accordingly, we advance one or the other. */ - if (SEQ_LEQ(sblkp->start, cur->start)) + if (SEQ_LEQ(sblkp->start, cur->start)) { cur = TAILQ_PREV(cur, sackhole_head, scblink); - else + } else { sblkp--; + } } } @@ -634,41 +658,41 @@ tcp_free_sackholes(struct tcpcb *tp) { struct sackhole *q; - while ((q = TAILQ_FIRST(&tp->snd_holes)) != NULL) + while ((q = TAILQ_FIRST(&tp->snd_holes)) != NULL) { tcp_sackhole_remove(tp, q); + } tp->sackhint.sack_bytes_rexmit = 0; tp->sackhint.nexthole = NULL; tp->sack_newdata = 0; - } /* - * Partial ack handling within a sack recovery episode. + * Partial ack handling within a sack recovery episode. * Keeping this very simple for now. When a partial ack * is received, force snd_cwnd to a value that will allow * the sender to transmit no more than 2 segments. - * If necessary, a better scheme can be adopted at a + * If necessary, a better scheme can be adopted at a * later point, but for now, the goal is to prevent the * sender from bursting a large amount of data in the midst * of sack recovery. */ void -tcp_sack_partialack(tp, th) - struct tcpcb *tp; - struct tcphdr *th; +tcp_sack_partialack(struct tcpcb *tp, struct tcphdr *th) { int num_segs = 1; tp->t_timer[TCPT_REXMT] = 0; tp->t_rtttime = 0; /* send one or 2 segments based on how much new data was acked */ - if (((BYTES_ACKED(th, tp)) / tp->t_maxseg) > 2) + if (((BYTES_ACKED(th, tp)) / tp->t_maxseg) > 2) { num_segs = 2; + } tp->snd_cwnd = (tp->sackhint.sack_bytes_rexmit + - (tp->snd_nxt - tp->sack_newdata) + - num_segs * tp->t_maxseg); - if (tp->snd_cwnd > tp->snd_ssthresh) + (tp->snd_nxt - tp->sack_newdata) + + num_segs * tp->t_maxseg); + if (tp->snd_cwnd > tp->snd_ssthresh) { tp->snd_cwnd = tp->snd_ssthresh; + } if (SEQ_LT(tp->snd_fack, tp->snd_recover) && tp->snd_fack == th->th_ack && TAILQ_EMPTY(&tp->snd_holes)) { struct sackhole *temp; @@ -680,8 +704,9 @@ tcp_sack_partialack(tp, th) */ temp = tcp_sackhole_insert(tp, tp->snd_fack, tp->snd_recover, NULL); - if (temp != NULL) + if (temp != NULL) { tp->snd_fack = tp->snd_recover; + } } (void) tcp_output(tp); } @@ -706,7 +731,7 @@ tcp_sack_output_debug(struct tcpcb *tp, int *sack_bytes_rexmt) } *sack_bytes_rexmt += (p->rxmit - p->start); } - return (p); + return p; } /* @@ -735,8 +760,9 @@ tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt) dbg_hole = tcp_sack_output_debug(tp, &dbg_bytes_rexmt); *sack_bytes_rexmt = tp->sackhint.sack_bytes_rexmit; hole = tp->sackhint.nexthole; - if (hole == NULL || SEQ_LT(hole->rxmit, hole->end)) + if (hole == NULL || SEQ_LT(hole->rxmit, hole->end)) { goto out; + } while ((hole = TAILQ_NEXT(hole, scblink)) != NULL) { if (SEQ_LT(hole->rxmit, hole->end)) { tp->sackhint.nexthole = hole; @@ -750,11 +776,11 @@ out: } if (*sack_bytes_rexmt != dbg_bytes_rexmt) { printf("%s: Computed sack_bytes_retransmitted (%d) not " - "the same as cached value (%d)\n", - __func__, dbg_bytes_rexmt, *sack_bytes_rexmt); + "the same as cached value (%d)\n", + __func__, dbg_bytes_rexmt, *sack_bytes_rexmt); *sack_bytes_rexmt = dbg_bytes_rexmt; } - return (hole); + return hole; } /* @@ -767,34 +793,38 @@ tcp_sack_adjust(struct tcpcb *tp) { struct sackhole *p, *cur = TAILQ_FIRST(&tp->snd_holes); - if (cur == NULL) + if (cur == NULL) { return; /* No holes */ - if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack)) + } + if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack)) { return; /* We're already beyond any SACKed blocks */ + } /* * Two cases for which we want to advance snd_nxt: * i) snd_nxt lies between end of one hole and beginning of another * ii) snd_nxt lies between end of last hole and snd_fack */ while ((p = TAILQ_NEXT(cur, scblink)) != NULL) { - if (SEQ_LT(tp->snd_nxt, cur->end)) + if (SEQ_LT(tp->snd_nxt, cur->end)) { return; - if (SEQ_GEQ(tp->snd_nxt, p->start)) + } + if (SEQ_GEQ(tp->snd_nxt, p->start)) { cur = p; - else { + } else { tp->snd_nxt = p->start; return; } } - if (SEQ_LT(tp->snd_nxt, cur->end)) + if (SEQ_LT(tp->snd_nxt, cur->end)) { return; + } tp->snd_nxt = tp->snd_fack; return; } /* * This function returns TRUE if more than (tcprexmtthresh - 1) * SMSS - * bytes with sequence numbers greater than snd_una have been SACKed. + * bytes with sequence numbers greater than snd_una have been SACKed. */ boolean_t tcp_sack_byte_islost(struct tcpcb *tp) @@ -803,8 +833,9 @@ tcp_sack_byte_islost(struct tcpcb *tp) struct sackhole *sndhole; if (!SACK_ENABLED(tp) || IN_FASTRECOVERY(tp) || TAILQ_EMPTY(&tp->snd_holes) || - (tp->t_flagsext & TF_PKTS_REORDERED)) - return (FALSE); + (tp->t_flagsext & TF_PKTS_REORDERED)) { + return FALSE; + } unacked_bytes = tp->snd_max - tp->snd_una; @@ -813,8 +844,8 @@ tcp_sack_byte_islost(struct tcpcb *tp) } VERIFY(unacked_bytes >= sndhole_bytes); - return ((unacked_bytes - sndhole_bytes) > - ((tcprexmtthresh - 1) * tp->t_maxseg)); + return (unacked_bytes - sndhole_bytes) > + ((tcprexmtthresh - 1) * tp->t_maxseg); } /* @@ -861,7 +892,7 @@ tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to, * returning true here so that the ack will not be * treated as duplicate ack. */ - return (TRUE); + return TRUE; } } else if (to->to_nsacks > 1 && SEQ_LEQ(second_sack.start, first_sack.start) && @@ -880,11 +911,11 @@ tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to, to->to_nsacks--; to->to_sacks += TCPOLEN_SACK; tcpstat.tcps_dsack_recvd_old++; - return (TRUE); + return TRUE; } } else { /* no dsack options, proceed with processing the sack */ - return (FALSE); + return FALSE; } /* Update the tcpopt pointer to exclude dsack block */ @@ -894,15 +925,17 @@ tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to, tp->t_dsack_recvd++; /* ignore DSACK option, if DSACK is disabled */ - if (tp->t_flagsext & TF_DISABLE_DSACK) - return (TRUE); + if (tp->t_flagsext & TF_DISABLE_DSACK) { + return TRUE; + } /* If the DSACK is for TLP mark it as such */ if ((tp->t_flagsext & TF_SENT_TLPROBE) && first_sack.end == tp->t_tlphighrxt) { if ((rxseg = tcp_rxtseg_find(tp, first_sack.start, - (first_sack.end - 1))) != NULL) + (first_sack.end - 1))) != NULL) { rxseg->rx_flags |= TCP_RXT_DSACK_FOR_TLP; + } } /* Update the sender's retransmit segment state */ if (((tp->t_rxtshift == 1 && first_sack.start == tp->snd_una) || @@ -921,7 +954,7 @@ tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to, */ tcpstat.tcps_dsack_ackloss++; - return (TRUE); + return TRUE; } else if ((rxseg = tcp_rxtseg_find(tp, first_sack.start, (first_sack.end - 1))) == NULL) { /* @@ -938,10 +971,11 @@ tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to, * If the segment was retransmitted only once, mark it as * spurious. Otherwise ignore the duplicate notification. */ - if (rxseg->rx_count == 1) + if (rxseg->rx_count == 1) { rxseg->rx_flags |= TCP_RXT_SPURIOUS; - else + } else { rxseg->rx_flags &= ~TCP_RXT_SPURIOUS; + } } - return (TRUE); + return TRUE; }