Mercurial > hg > nginx
view src/os/unix/ngx_readv_chain.c @ 9236:d9a52ebb9b00
Mail: max_commands directive.
The directive specifies the maximum number of commands allowed during
authentication, after which the connection is closed. The default
limit is 1000, which is not expected to affect any well-behaving clients,
since authentication usually requires at most several commands, though
will effectively stop malicious clients from flooding the server with
with commands.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 30 Mar 2024 05:05:53 +0300 |
parents | f3510cb959d1 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain, off_t limit) { u_char *prev; ssize_t n, size; ngx_err_t err; ngx_array_t vec; ngx_event_t *rev; struct iovec *iov, iovs[NGX_IOVS_PREALLOCATE]; rev = c->read; #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: eof:%d, avail:%d, err:%d", rev->pending_eof, rev->available, rev->kq_errno); if (rev->available == 0) { if (rev->pending_eof) { rev->ready = 0; rev->eof = 1; ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno, "kevent() reported about an closed connection"); if (rev->kq_errno) { rev->error = 1; ngx_set_socket_errno(rev->kq_errno); return NGX_ERROR; } return 0; } else { rev->ready = 0; return NGX_AGAIN; } } } #endif #if (NGX_HAVE_EPOLLRDHUP) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: eof:%d, avail:%d", rev->pending_eof, rev->available); if (rev->available == 0 && !rev->pending_eof) { rev->ready = 0; return NGX_AGAIN; } } #endif prev = NULL; iov = NULL; size = 0; vec.elts = iovs; vec.nelts = 0; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS_PREALLOCATE; vec.pool = c->pool; /* coalesce the neighbouring bufs */ while (chain) { n = chain->buf->end - chain->buf->last; if (limit) { if (size >= limit) { break; } if (size + n > limit) { n = (ssize_t) (limit - size); } } if (prev == chain->buf->last) { iov->iov_len += n; } else { if (vec.nelts == vec.nalloc) { break; } iov = ngx_array_push(&vec); if (iov == NULL) { return NGX_ERROR; } iov->iov_base = (void *) chain->buf->last; iov->iov_len = n; } size += n; prev = chain->buf->end; chain = chain->next; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: %ui, last:%uz", vec.nelts, iov->iov_len); do { n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts); if (n == 0) { rev->ready = 0; rev->eof = 1; #if (NGX_HAVE_KQUEUE) /* * on FreeBSD readv() may return 0 on closed socket * even if kqueue reported about available data */ if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available = 0; } #endif return 0; } if (n > 0) { #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available -= n; /* * rev->available may be negative here because some additional * bytes may be received between kevent() and readv() */ if (rev->available <= 0) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif #if (NGX_HAVE_FIONREAD) if (rev->available >= 0) { rev->available -= n; /* * negative rev->available means some additional bytes * were received between kernel notification and readv(), * and therefore ev->ready can be safely reset even for * edge-triggered event methods */ if (rev->available < 0) { rev->available = 0; rev->ready = 0; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: avail:%d", rev->available); } else if (n == size) { if (ngx_socket_nread(c->fd, &rev->available) == -1) { n = ngx_connection_error(c, ngx_socket_errno, ngx_socket_nread_n " failed"); break; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: avail:%d", rev->available); } #endif #if (NGX_HAVE_EPOLLRDHUP) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) { if (n < size) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) { rev->ready = 0; } return n; } err = ngx_socket_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "readv() not ready"); n = NGX_AGAIN; } else { n = ngx_connection_error(c, err, "readv() failed"); break; } } while (err == NGX_EINTR); rev->ready = 0; if (n == NGX_ERROR) { c->read->error = 1; } return n; }