Mercurial > hg > nginx-quic
view src/os/unix/ngx_solaris_sendfilev_chain.c @ 8867:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +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; } } }