Mercurial > hg > nginx
view src/os/unix/ngx_solaris_sendfilev_chain.c @ 6893:a3e6d660b179 stable-1.10
Fixed trailer construction with limit on FreeBSD and macOS.
The ngx_chain_coalesce_file() function may produce more bytes to send then
requested in the limit passed, as it aligns the last file position
to send to memory page boundary. As a result, (limit - send) may become
negative. This resulted in big positive number when converted to size_t
while calling ngx_output_chain_to_iovec().
Another part of the problem is in ngx_chain_coalesce_file(): it changes cl
to the next chain link even if the current buffer is only partially sent
due to limit.
Therefore, if a file buffer was not expected to be fully sent due to limit,
and was followed by a memory buffer, nginx called sendfile() with a part
of the file buffer, and the memory buffer in trailer. If there were enough
room in the socket buffer, this resulted in a part of the file buffer being
skipped, and corresponding part of the memory buffer sent instead.
The bug was introduced in 8e903522c17a (1.7.8). Configurations affected
are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and
memory buffers after file ones (may happen when using subrequests or
with proxying with disk buffering).
Fix is to explicitly check if (send < limit) before constructing trailer
with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file()
was modified to preserve unfinished file buffers in cl.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 20 Jan 2017 21:12:48 +0300 |
parents | 646985c55393 |
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> #if (NGX_TEST_BUILD_SOLARIS_SENDFILEV) /* Solaris declarations */ typedef struct sendfilevec { int sfv_fd; u_int sfv_flag; off_t sfv_off; size_t sfv_len; } sendfilevec_t; #define SFV_FD_SELF -2 static ssize_t sendfilev(int fd, const struct sendfilevec *vec, int sfvcnt, size_t *xferred) { return -1; } ngx_chain_t *ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit); #endif #define NGX_SENDFILEVECS NGX_IOVS_PREALLOCATE ngx_chain_t * ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int fd; u_char *prev; off_t size, send, prev_send, aligned, fprev; size_t sent; ssize_t n; ngx_int_t eintr; ngx_err_t err; ngx_buf_t *file; ngx_uint_t nsfv; sendfilevec_t *sfv, sfvs[NGX_SENDFILEVECS]; ngx_event_t *wev; ngx_chain_t *cl; wev = c->write; if (!wev->ready) { return in; } if (!c->sendfile) { return ngx_writev_chain(c, in, limit); } /* 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; for ( ;; ) { fd = SFV_FD_SELF; prev = NULL; fprev = 0; file = NULL; sfv = NULL; eintr = 0; sent = 0; prev_send = send; nsfv = 0; /* create the sendfilevec and coalesce the neighbouring bufs */ for (cl = in; cl && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } if (ngx_buf_in_memory_only(cl->buf)) { fd = SFV_FD_SELF; size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = limit - send; } if (prev == cl->buf->pos) { sfv->sfv_len += (size_t) size; } else { if (nsfv == NGX_SENDFILEVECS) { break; } sfv = &sfvs[nsfv++]; sfv->sfv_fd = SFV_FD_SELF; sfv->sfv_flag = 0; sfv->sfv_off = (off_t) (uintptr_t) cl->buf->pos; sfv->sfv_len = (size_t) size; } prev = cl->buf->pos + (size_t) size; send += size; } else { prev = NULL; size = cl->buf->file_last - cl->buf->file_pos; if (send + size > limit) { size = limit - send; aligned = (cl->buf->file_pos + size + ngx_pagesize - 1) & ~((off_t) ngx_pagesize - 1); if (aligned <= cl->buf->file_last) { size = aligned - cl->buf->file_pos; } } if (fd == cl->buf->file->fd && fprev == cl->buf->file_pos) { sfv->sfv_len += (size_t) size; } else { if (nsfv == NGX_SENDFILEVECS) { break; } sfv = &sfvs[nsfv++]; fd = cl->buf->file->fd; sfv->sfv_fd = fd; sfv->sfv_flag = 0; sfv->sfv_off = cl->buf->file_pos; sfv->sfv_len = (size_t) size; } file = cl->buf; fprev = cl->buf->file_pos + size; send += size; } } n = sendfilev(c->fd, sfvs, nsfv, &sent); if (n == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; ngx_connection_error(c, err, "sendfilev() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err, "sendfilev() sent only %uz bytes", sent); } else if (n == 0 && sent == 0) { /* * sendfilev() is documented to return -1 with errno * set to EINVAL if svf_len is greater than the file size, * but at least Solaris 11 returns 0 instead */ if (file) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "sendfilev() reported that \"%s\" was truncated at %O", file->file->name.data, file->file_pos); } else { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "sendfilev() returned 0 with memory buffers"); } return NGX_CHAIN_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfilev: %z %z", n, sent); c->sent += sent; in = ngx_chain_update_sent(in, sent); if (eintr) { send = prev_send + sent; continue; } if (send - prev_send != (off_t) sent) { wev->ready = 0; return in; } if (send >= limit || in == NULL) { return in; } } }