Mercurial > hg > nginx-quic
view src/os/unix/ngx_writev_chain.c @ 8149:44991d728899 quic
QUIC: account packet header length in amplification limit.
This is the restoration of 02ee77f8d53d accidentally reverted by 93be5658a250.
author | Vladimir Homutov <vl@nginx.com> |
---|---|
date | Mon, 19 Oct 2020 12:19:38 +0300 |
parents | 2c64b69daec5 |
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> ngx_chain_t * ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { ssize_t n, sent; off_t send, prev_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 ( ;; ) { prev_send = send; /* create the iovec and coalesce the neighbouring bufs */ cl = ngx_output_chain_to_iovec(&vec, in, limit - send, 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 writev " "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; } send += vec.size; n = ngx_writev(c, &vec); if (n == NGX_ERROR) { return NGX_CHAIN_ERROR; } sent = (n == NGX_AGAIN) ? 0 : n; c->sent += sent; in = ngx_chain_update_sent(in, sent); if (send - prev_send != sent) { wev->ready = 0; return in; } if (send >= limit || in == NULL) { return in; } } } ngx_chain_t * ngx_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, size_t limit, ngx_log_t *log) { size_t total, size; u_char *prev; ngx_uint_t n; struct iovec *iov; iov = NULL; prev = NULL; total = 0; n = 0; for ( /* void */ ; in && total < limit; in = in->next) { 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 (size > limit - total) { size = limit - total; } if (prev == in->buf->pos) { iov->iov_len += size; } else { if (n == vec->nalloc) { break; } iov = &vec->iovs[n++]; iov->iov_base = (void *) in->buf->pos; iov->iov_len = size; } prev = in->buf->pos + size; total += size; } vec->count = n; vec->size = total; return in; } ssize_t ngx_writev(ngx_connection_t *c, ngx_iovec_t *vec) { ssize_t n; ngx_err_t err; eintr: n = writev(c->fd, vec->iovs, vec->count); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %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, "writev() not ready"); return NGX_AGAIN; case NGX_EINTR: ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "writev() was interrupted"); goto eintr; default: c->write->error = 1; ngx_connection_error(c, err, "writev() failed"); return NGX_ERROR; } } return n; }