Mercurial > hg > nginx
changeset 8822:ad046179eb91 quic
QUIC: handle EAGAIN properly on UDP sockets.
Previously, the error was ignored leading to unnecessary retransmits.
Now, unsent frames are returned into output queue, state is reset, and
timer is started for the next send attempt.
| author | Vladimir Homutov <vl@nginx.com> |
|---|---|
| date | Wed, 28 Jul 2021 17:23:18 +0300 |
| parents | d80365ca678d |
| children | f3331deed357 |
| files | src/event/quic/ngx_event_quic.c src/event/quic/ngx_event_quic_connection.h src/event/quic/ngx_event_quic_migration.c src/event/quic/ngx_event_quic_output.c src/event/quic/ngx_event_quic_transport.h |
| diffstat | 5 files changed, 136 insertions(+), 56 deletions(-) [+] |
line wrap: on
line diff
--- a/src/event/quic/ngx_event_quic.c Thu Jul 29 10:03:36 2021 +0300 +++ b/src/event/quic/ngx_event_quic.c Wed Jul 28 17:23:18 2021 +0300 @@ -255,6 +255,7 @@ for (i = 0; i < NGX_QUIC_SEND_CTX_LAST; i++) { ngx_queue_init(&qc->send_ctx[i].frames); + ngx_queue_init(&qc->send_ctx[i].sending); ngx_queue_init(&qc->send_ctx[i].sent); qc->send_ctx[i].largest_pn = NGX_QUIC_UNSET_PN; qc->send_ctx[i].largest_ack = NGX_QUIC_UNSET_PN;
--- a/src/event/quic/ngx_event_quic_connection.h Thu Jul 29 10:03:36 2021 +0300 +++ b/src/event/quic/ngx_event_quic_connection.h Wed Jul 28 17:23:18 2021 +0300 @@ -161,8 +161,9 @@ uint64_t largest_ack; /* received from peer */ uint64_t largest_pn; /* received from peer */ - ngx_queue_t frames; - ngx_queue_t sent; + ngx_queue_t frames; /* generated frames */ + ngx_queue_t sending; /* frames assigned to pkt */ + ngx_queue_t sent; /* frames waiting ACK */ uint64_t pending_ack; /* non sent ack-eliciting */ uint64_t largest_range;
--- a/src/event/quic/ngx_event_quic_migration.c Thu Jul 29 10:03:36 2021 +0300 +++ b/src/event/quic/ngx_event_quic_migration.c Wed Jul 28 17:23:18 2021 +0300 @@ -55,7 +55,7 @@ pad = ngx_min(1200, max); sent = ngx_quic_frame_sendto(c, &frame, pad, path->sockaddr, path->socklen); - if (sent == -1) { + if (sent < 0) { return NGX_ERROR; } @@ -606,7 +606,7 @@ pad = ngx_min(1200, max); sent = ngx_quic_frame_sendto(c, &frame, pad, path->sockaddr, path->socklen); - if (sent == -1) { + if (sent < 0) { return NGX_ERROR; } @@ -618,7 +618,7 @@ pad = ngx_min(1200, max); sent = ngx_quic_frame_sendto(c, &frame, pad, path->sockaddr, path->socklen); - if (sent == -1) { + if (sent < 0) { return NGX_ERROR; }
--- a/src/event/quic/ngx_event_quic_output.c Thu Jul 29 10:03:36 2021 +0300 +++ b/src/event/quic/ngx_event_quic_output.c Wed Jul 28 17:23:18 2021 +0300 @@ -39,11 +39,16 @@ #define NGX_QUIC_CC_MIN_INTERVAL 1000 /* 1s */ +#define NGX_QUIC_SOCKET_RETRY_DELAY 10 /* ms, for NGX_AGAIN on write */ + static ngx_int_t ngx_quic_socket_output(ngx_connection_t *c, ngx_quic_socket_t *qsock); static ngx_int_t ngx_quic_create_datagrams(ngx_connection_t *c, ngx_quic_socket_t *qsock); +static void ngx_quic_commit_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx); +static void ngx_quic_revert_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx, + uint64_t pnum); #if ((NGX_HAVE_UDP_SEGMENT) && (NGX_HAVE_MSGHDR_MSG_CONTROL)) static ngx_uint_t ngx_quic_allow_segmentation(ngx_connection_t *c, ngx_quic_socket_t *qsock); @@ -138,6 +143,7 @@ size_t len, min; ssize_t n; u_char *p; + uint64_t preserved_pnum[NGX_QUIC_SEND_CTX_LAST]; ngx_uint_t i, pad; ngx_quic_path_t *path; ngx_quic_send_ctx_t *ctx; @@ -145,7 +151,6 @@ static u_char dst[NGX_QUIC_MAX_UDP_PAYLOAD_SIZE]; qc = ngx_quic_get_connection(c); - path = qsock->path; for ( ;; ) { @@ -167,6 +172,8 @@ ctx = &qc->send_ctx[i]; + preserved_pnum[i] = ctx->pnum; + if (ngx_quic_generate_ack(c, ctx) != NGX_OK) { return NGX_ERROR; } @@ -194,6 +201,19 @@ return NGX_ERROR; } + if (n == NGX_AGAIN) { + for (i = 0; i < NGX_QUIC_SEND_CTX_LAST; i++) { + ngx_quic_revert_send(c, &qc->send_ctx[i], preserved_pnum[i]); + } + + ngx_add_timer(&qc->push, NGX_QUIC_SOCKET_RETRY_DELAY); + break; + } + + for (i = 0; i < NGX_QUIC_SEND_CTX_LAST; i++) { + ngx_quic_commit_send(c, &qc->send_ctx[i]); + } + path->sent += len; } @@ -201,6 +221,57 @@ } +static void +ngx_quic_commit_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx) +{ + ngx_queue_t *q; + ngx_quic_frame_t *f; + ngx_quic_congestion_t *cg; + ngx_quic_connection_t *qc; + + qc = ngx_quic_get_connection(c); + + cg = &qc->congestion; + + while (!ngx_queue_empty(&ctx->sending)) { + + q = ngx_queue_head(&ctx->sending); + f = ngx_queue_data(q, ngx_quic_frame_t, queue); + + ngx_queue_remove(q); + + if (f->pkt_need_ack && !qc->closing) { + ngx_queue_insert_tail(&ctx->sent, q); + + cg->in_flight += f->plen; + + } else { + ngx_quic_free_frame(c, f); + } + } + + ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, + "quic congestion send if:%uz", cg->in_flight); +} + + +static void +ngx_quic_revert_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx, + uint64_t pnum) +{ + ngx_queue_t *q; + + while (!ngx_queue_empty(&ctx->sending)) { + + q = ngx_queue_last(&ctx->sending); + ngx_queue_remove(q); + ngx_queue_insert_head(&ctx->frames, q); + } + + ctx->pnum = pnum; +} + + #if ((NGX_HAVE_UDP_SEGMENT) && (NGX_HAVE_MSGHDR_MSG_CONTROL)) static ngx_uint_t @@ -264,9 +335,10 @@ size_t len, segsize; ssize_t n; u_char *p, *end; + uint64_t preserved_pnum; ngx_uint_t nseg; + ngx_quic_path_t *path; ngx_quic_send_ctx_t *ctx; - ngx_quic_path_t *path; ngx_quic_connection_t *qc; static u_char dst[NGX_QUIC_MAX_UDP_SEGMENT_BUF]; @@ -286,6 +358,8 @@ nseg = 0; + preserved_pnum = ctx->pnum; + for ( ;; ) { len = ngx_min(segsize, (size_t) (end - p)); @@ -315,10 +389,20 @@ return NGX_ERROR; } + if (n == NGX_AGAIN) { + ngx_quic_revert_send(c, ctx, preserved_pnum); + + ngx_add_timer(&qc->push, NGX_QUIC_SOCKET_RETRY_DELAY); + break; + } + + ngx_quic_commit_send(c, ctx); + path->sent += n; p = dst; nseg = 0; + preserved_pnum = ctx->pnum; } } @@ -380,8 +464,8 @@ msg.msg_controllen = clen; n = ngx_sendmsg(c, &msg, 0); - if (n == -1) { - return NGX_ERROR; + if (n < 0) { + return n; } c->sent += n; @@ -622,32 +706,20 @@ ctx->pnum++; if (pkt.need_ack) { - /* move frames into the sent queue to wait for ack */ - - if (!qc->closing) { - q = ngx_queue_head(&ctx->frames); - f = ngx_queue_data(q, ngx_quic_frame_t, queue); - f->plen = res.len; + q = ngx_queue_head(&ctx->frames); + f = ngx_queue_data(q, ngx_quic_frame_t, queue); - do { - q = ngx_queue_head(&ctx->frames); - ngx_queue_remove(q); - ngx_queue_insert_tail(&ctx->sent, q); - } while (--nframes); - } - - cg->in_flight += res.len; - - ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, - "quic congestion send if:%uz", cg->in_flight); + f->plen = res.len; } while (nframes--) { q = ngx_queue_head(&ctx->frames); f = ngx_queue_data(q, ngx_quic_frame_t, queue); + f->pkt_need_ack = pkt.need_ack; + ngx_queue_remove(q); - ngx_quic_free_frame(c, f); + ngx_queue_insert_tail(&ctx->sending, q); } return res.len; @@ -658,37 +730,46 @@ ngx_quic_send(ngx_connection_t *c, u_char *buf, size_t len, struct sockaddr *sockaddr, socklen_t socklen) { - ngx_buf_t b; - socklen_t orig_socklen; - ngx_chain_t cl, *res; - struct sockaddr *orig_sockaddr; + ssize_t n; + struct iovec iov; + struct msghdr msg; +#if defined(NGX_HAVE_ADDRINFO_CMSG) + struct cmsghdr *cmsg; + char msg_control[CMSG_SPACE(sizeof(ngx_addrinfo_t))]; +#endif - ngx_memzero(&b, sizeof(ngx_buf_t)); + ngx_memzero(&msg, sizeof(struct msghdr)); - b.pos = b.start = buf; - b.last = b.end = buf + len; - b.last_buf = 1; - b.temporary = 1; + iov.iov_len = len; + iov.iov_base = buf; + + msg.msg_iov = &iov; + msg.msg_iovlen = 1; - cl.buf = &b; - cl.next= NULL; + msg.msg_name = sockaddr; + msg.msg_namelen = socklen; - orig_socklen = c->socklen; - orig_sockaddr = c->sockaddr; +#if defined(NGX_HAVE_ADDRINFO_CMSG) + if (c->listening && c->listening->wildcard && c->local_sockaddr) { + + msg.msg_control = msg_control; + msg.msg_controllen = sizeof(msg_control); + ngx_memzero(msg_control, sizeof(msg_control)); - c->sockaddr = sockaddr; - c->socklen = socklen; - - res = c->send_chain(c, &cl, 0); + cmsg = CMSG_FIRSTHDR(&msg); - c->sockaddr = orig_sockaddr; - c->socklen = orig_socklen; + msg.msg_controllen = ngx_set_srcaddr_cmsg(cmsg, c->local_sockaddr); + } +#endif - if (res == NGX_CHAIN_ERROR) { - return NGX_ERROR; + n = ngx_sendmsg(c, &msg, 0); + if (n < 0) { + return n; } - return len; + c->sent += n; + + return n; } @@ -945,9 +1026,7 @@ return NGX_ERROR; } - if (ngx_quic_send(c, res.data, res.len, c->sockaddr, c->socklen) - == NGX_ERROR) - { + if (ngx_quic_send(c, res.data, res.len, c->sockaddr, c->socklen) < 0) { return NGX_ERROR; } @@ -1006,7 +1085,7 @@ #endif len = ngx_quic_send(c, res.data, res.len, c->sockaddr, c->socklen); - if (len == NGX_ERROR) { + if (len < 0) { return NGX_ERROR; } @@ -1221,7 +1300,5 @@ ctx->pnum++; - len = ngx_quic_send(c, res.data, res.len, sockaddr, socklen); - - return len; + return ngx_quic_send(c, res.data, res.len, sockaddr, socklen); }