Mercurial > hg > nginx-quic
view src/os/unix/ngx_udp_sendmsg_chain.c @ 8481:a45b6a206cfc stable-1.20
Resolver: fixed label types handling in ngx_resolver_copy().
Previously, anything with any of the two high bits set were interpreted
as compression pointers. This is incorrect, as RFC 1035 clearly states
that "The 10 and 01 combinations are reserved for future use". Further,
the 01 combination is actually allocated for EDNS extended label type
(see RFC 2671 and RFC 6891), not really used though.
Fix is to reject unrecognized label types rather than misinterpreting
them as compression pointers.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 25 May 2021 15:17:41 +0300 |
parents | d127837c714f |
children | 2dfd313f22f2 cfe1284e5d1d |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static ngx_chain_t *ngx_udp_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, ngx_log_t *log); static ssize_t ngx_sendmsg(ngx_connection_t *c, ngx_iovec_t *vec); ngx_chain_t * ngx_udp_unix_sendmsg_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { ssize_t n; off_t send; ngx_chain_t *cl; ngx_event_t *wev; ngx_iovec_t vec; struct iovec iovs[NGX_IOVS_PREALLOCATE]; wev = c->write; if (!wev->ready) { return in; } #if (NGX_HAVE_KQUEUE) if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) { (void) ngx_connection_error(c, wev->kq_errno, "kevent() reported about an closed connection"); wev->error = 1; return NGX_CHAIN_ERROR; } #endif /* the maximum limit size is the maximum size_t value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) { limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize; } send = 0; vec.iovs = iovs; vec.nalloc = NGX_IOVS_PREALLOCATE; for ( ;; ) { /* create the iovec and coalesce the neighbouring bufs */ cl = ngx_udp_output_chain_to_iovec(&vec, in, c->log); if (cl == NGX_CHAIN_ERROR) { return NGX_CHAIN_ERROR; } if (cl && cl->buf->in_file) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "file buf in sendmsg " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_CHAIN_ERROR; } if (cl == in) { return in; } send += vec.size; n = ngx_sendmsg(c, &vec); if (n == NGX_ERROR) { return NGX_CHAIN_ERROR; } if (n == NGX_AGAIN) { wev->ready = 0; return in; } c->sent += n; in = ngx_chain_update_sent(in, n); if (send >= limit || in == NULL) { return in; } } } static ngx_chain_t * ngx_udp_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, ngx_log_t *log) { size_t total, size; u_char *prev; ngx_uint_t n, flush; ngx_chain_t *cl; struct iovec *iov; cl = in; iov = NULL; prev = NULL; total = 0; n = 0; flush = 0; for ( /* void */ ; in && !flush; in = in->next) { if (in->buf->flush || in->buf->last_buf) { flush = 1; } if (ngx_buf_special(in->buf)) { continue; } if (in->buf->in_file) { break; } if (!ngx_buf_in_memory(in->buf)) { ngx_log_error(NGX_LOG_ALERT, log, 0, "bad buf in output chain " "t:%d r:%d f:%d %p %p-%p %p %O-%O", in->buf->temporary, in->buf->recycled, in->buf->in_file, in->buf->start, in->buf->pos, in->buf->last, in->buf->file, in->buf->file_pos, in->buf->file_last); ngx_debug_point(); return NGX_CHAIN_ERROR; } size = in->buf->last - in->buf->pos; if (prev == in->buf->pos) { iov->iov_len += size; } else { if (n == vec->nalloc) { ngx_log_error(NGX_LOG_ALERT, log, 0, "too many parts in a datagram"); return NGX_CHAIN_ERROR; } iov = &vec->iovs[n++]; iov->iov_base = (void *) in->buf->pos; iov->iov_len = size; } prev = in->buf->pos + size; total += size; } if (!flush) { #if (NGX_SUPPRESS_WARN) vec->size = 0; vec->count = 0; #endif return cl; } /* zero-sized datagram; pretend to have at least 1 iov */ if (n == 0) { iov = &vec->iovs[n++]; iov->iov_base = NULL; iov->iov_len = 0; } vec->count = n; vec->size = total; return in; } static ssize_t ngx_sendmsg(ngx_connection_t *c, ngx_iovec_t *vec) { ssize_t n; ngx_err_t err; struct msghdr msg; #if (NGX_HAVE_MSGHDR_MSG_CONTROL) #if (NGX_HAVE_IP_SENDSRCADDR) u_char msg_control[CMSG_SPACE(sizeof(struct in_addr))]; #elif (NGX_HAVE_IP_PKTINFO) u_char msg_control[CMSG_SPACE(sizeof(struct in_pktinfo))]; #endif #if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO) u_char msg_control6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; #endif #endif ngx_memzero(&msg, sizeof(struct msghdr)); if (c->socklen) { msg.msg_name = c->sockaddr; msg.msg_namelen = c->socklen; } msg.msg_iov = vec->iovs; msg.msg_iovlen = vec->count; #if (NGX_HAVE_MSGHDR_MSG_CONTROL) if (c->listening && c->listening->wildcard && c->local_sockaddr) { #if (NGX_HAVE_IP_SENDSRCADDR) if (c->local_sockaddr->sa_family == AF_INET) { struct cmsghdr *cmsg; struct in_addr *addr; struct sockaddr_in *sin; msg.msg_control = &msg_control; msg.msg_controllen = sizeof(msg_control); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = IPPROTO_IP; cmsg->cmsg_type = IP_SENDSRCADDR; cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr)); sin = (struct sockaddr_in *) c->local_sockaddr; addr = (struct in_addr *) CMSG_DATA(cmsg); *addr = sin->sin_addr; } #elif (NGX_HAVE_IP_PKTINFO) if (c->local_sockaddr->sa_family == AF_INET) { struct cmsghdr *cmsg; struct in_pktinfo *pkt; struct sockaddr_in *sin; msg.msg_control = &msg_control; msg.msg_controllen = sizeof(msg_control); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = IPPROTO_IP; cmsg->cmsg_type = IP_PKTINFO; cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); sin = (struct sockaddr_in *) c->local_sockaddr; pkt = (struct in_pktinfo *) CMSG_DATA(cmsg); ngx_memzero(pkt, sizeof(struct in_pktinfo)); pkt->ipi_spec_dst = sin->sin_addr; } #endif #if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO) if (c->local_sockaddr->sa_family == AF_INET6) { struct cmsghdr *cmsg; struct in6_pktinfo *pkt6; struct sockaddr_in6 *sin6; msg.msg_control = &msg_control6; msg.msg_controllen = sizeof(msg_control6); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = IPPROTO_IPV6; cmsg->cmsg_type = IPV6_PKTINFO; cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); sin6 = (struct sockaddr_in6 *) c->local_sockaddr; pkt6 = (struct in6_pktinfo *) CMSG_DATA(cmsg); ngx_memzero(pkt6, sizeof(struct in6_pktinfo)); pkt6->ipi6_addr = sin6->sin6_addr; } #endif } #endif eintr: n = sendmsg(c->fd, &msg, 0); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendmsg: %z of %uz", n, vec->size); if (n == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendmsg() not ready"); return NGX_AGAIN; case NGX_EINTR: ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendmsg() was interrupted"); goto eintr; default: c->write->error = 1; ngx_connection_error(c, err, "sendmsg() failed"); return NGX_ERROR; } } return n; }