Mercurial > hg > nginx-quic
view src/http/ngx_http_copy_filter_module.c @ 7507:ea05113adbdb
Range filter: fixed loss of incoming chain links.
Filters are not allowed to change incoming chain links, and should allocate
their own links if any modifications are needed. Nevertheless
ngx_http_range_singlepart_body() modified incoming chain links in some
cases, notably at the end of the requested range.
No problems caused by this are currently known, mostly because of
limited number of possible modifications and the position of the range
body filter in the filter chain. Though this behaviour is clearly incorrect
and tests demonstrate that it can at least cause some proxy buffers being
lost when using proxy_force_ranges, leading to less effective handling
of responses.
Fix is to always allocate new chain links in ngx_http_range_singlepart_body().
Links are explicitly freed to ensure constant memory usage with long-lived
requests.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 13 May 2019 22:44:02 +0300 |
parents | ce37362a7a70 |
children | 555533169506 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_bufs_t bufs; } ngx_http_copy_filter_conf_t; #if (NGX_HAVE_FILE_AIO) static void ngx_http_copy_aio_handler(ngx_output_chain_ctx_t *ctx, ngx_file_t *file); static void ngx_http_copy_aio_event_handler(ngx_event_t *ev); #if (NGX_HAVE_AIO_SENDFILE) static ssize_t ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file); static void ngx_http_copy_aio_sendfile_event_handler(ngx_event_t *ev); #endif #endif #if (NGX_THREADS) static ngx_int_t ngx_http_copy_thread_handler(ngx_thread_task_t *task, ngx_file_t *file); static void ngx_http_copy_thread_event_handler(ngx_event_t *ev); #endif static void *ngx_http_copy_filter_create_conf(ngx_conf_t *cf); static char *ngx_http_copy_filter_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_copy_filter_init(ngx_conf_t *cf); static ngx_command_t ngx_http_copy_filter_commands[] = { { ngx_string("output_buffers"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2, ngx_conf_set_bufs_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_copy_filter_conf_t, bufs), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_copy_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_copy_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_copy_filter_create_conf, /* create location configuration */ ngx_http_copy_filter_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_copy_filter_module = { NGX_MODULE_V1, &ngx_http_copy_filter_module_ctx, /* module context */ ngx_http_copy_filter_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_copy_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_int_t rc; ngx_connection_t *c; ngx_output_chain_ctx_t *ctx; ngx_http_core_loc_conf_t *clcf; ngx_http_copy_filter_conf_t *conf; c = r->connection; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "http copy filter: \"%V?%V\"", &r->uri, &r->args); ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module); if (ctx == NULL) { ctx = ngx_pcalloc(r->pool, sizeof(ngx_output_chain_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_copy_filter_module); conf = ngx_http_get_module_loc_conf(r, ngx_http_copy_filter_module); clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); ctx->sendfile = c->sendfile; ctx->need_in_memory = r->main_filter_need_in_memory || r->filter_need_in_memory; ctx->need_in_temp = r->filter_need_temporary; ctx->alignment = clcf->directio_alignment; ctx->pool = r->pool; ctx->bufs = conf->bufs; ctx->tag = (ngx_buf_tag_t) &ngx_http_copy_filter_module; ctx->output_filter = (ngx_output_chain_filter_pt) ngx_http_next_body_filter; ctx->filter_ctx = r; #if (NGX_HAVE_FILE_AIO) if (ngx_file_aio && clcf->aio == NGX_HTTP_AIO_ON) { ctx->aio_handler = ngx_http_copy_aio_handler; #if (NGX_HAVE_AIO_SENDFILE) ctx->aio_preload = ngx_http_copy_aio_sendfile_preload; #endif } #endif #if (NGX_THREADS) if (clcf->aio == NGX_HTTP_AIO_THREADS) { ctx->thread_handler = ngx_http_copy_thread_handler; } #endif if (in && in->buf && ngx_buf_size(in->buf)) { r->request_output = 1; } } #if (NGX_HAVE_FILE_AIO || NGX_THREADS) ctx->aio = r->aio; #endif rc = ngx_output_chain(ctx, in); if (ctx->in == NULL) { r->buffered &= ~NGX_HTTP_COPY_BUFFERED; } else { r->buffered |= NGX_HTTP_COPY_BUFFERED; } ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0, "http copy filter: %i \"%V?%V\"", rc, &r->uri, &r->args); return rc; } #if (NGX_HAVE_FILE_AIO) static void ngx_http_copy_aio_handler(ngx_output_chain_ctx_t *ctx, ngx_file_t *file) { ngx_http_request_t *r; r = ctx->filter_ctx; file->aio->data = r; file->aio->handler = ngx_http_copy_aio_event_handler; r->main->blocked++; r->aio = 1; ctx->aio = 1; } static void ngx_http_copy_aio_event_handler(ngx_event_t *ev) { ngx_event_aio_t *aio; ngx_connection_t *c; ngx_http_request_t *r; aio = ev->data; r = aio->data; c = r->connection; ngx_http_set_log_request(c->log, r); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "http aio: \"%V?%V\"", &r->uri, &r->args); r->main->blocked--; r->aio = 0; r->write_event_handler(r); ngx_http_run_posted_requests(c); } #if (NGX_HAVE_AIO_SENDFILE) static ssize_t ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file) { ssize_t n; static u_char buf[1]; ngx_event_aio_t *aio; ngx_http_request_t *r; ngx_output_chain_ctx_t *ctx; n = ngx_file_aio_read(file->file, buf, 1, file->file_pos, NULL); if (n == NGX_AGAIN) { aio = file->file->aio; aio->handler = ngx_http_copy_aio_sendfile_event_handler; r = aio->data; r->main->blocked++; r->aio = 1; ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module); ctx->aio = 1; } return n; } static void ngx_http_copy_aio_sendfile_event_handler(ngx_event_t *ev) { ngx_event_aio_t *aio; ngx_http_request_t *r; aio = ev->data; r = aio->data; r->main->blocked--; r->aio = 0; ev->complete = 0; r->connection->write->handler(r->connection->write); } #endif #endif #if (NGX_THREADS) static ngx_int_t ngx_http_copy_thread_handler(ngx_thread_task_t *task, ngx_file_t *file) { ngx_str_t name; ngx_thread_pool_t *tp; ngx_http_request_t *r; ngx_output_chain_ctx_t *ctx; ngx_http_core_loc_conf_t *clcf; r = file->thread_ctx; clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); tp = clcf->thread_pool; if (tp == NULL) { if (ngx_http_complex_value(r, clcf->thread_pool_value, &name) != NGX_OK) { return NGX_ERROR; } tp = ngx_thread_pool_get((ngx_cycle_t *) ngx_cycle, &name); if (tp == NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "thread pool \"%V\" not found", &name); return NGX_ERROR; } } task->event.data = r; task->event.handler = ngx_http_copy_thread_event_handler; if (ngx_thread_task_post(tp, task) != NGX_OK) { return NGX_ERROR; } r->main->blocked++; r->aio = 1; ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module); ctx->aio = 1; return NGX_OK; } static void ngx_http_copy_thread_event_handler(ngx_event_t *ev) { ngx_connection_t *c; ngx_http_request_t *r; r = ev->data; c = r->connection; ngx_http_set_log_request(c->log, r); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "http thread: \"%V?%V\"", &r->uri, &r->args); r->main->blocked--; r->aio = 0; if (r->done) { /* * trigger connection event handler if the subrequest was * already finalized; this can happen if the handler is used * for sendfile() in threads */ c->write->handler(c->write); } else { r->write_event_handler(r); ngx_http_run_posted_requests(c); } } #endif static void * ngx_http_copy_filter_create_conf(ngx_conf_t *cf) { ngx_http_copy_filter_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_http_copy_filter_conf_t)); if (conf == NULL) { return NULL; } conf->bufs.num = 0; return conf; } static char * ngx_http_copy_filter_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_copy_filter_conf_t *prev = parent; ngx_http_copy_filter_conf_t *conf = child; ngx_conf_merge_bufs_value(conf->bufs, prev->bufs, 2, 32768); return NULL; } static ngx_int_t ngx_http_copy_filter_init(ngx_conf_t *cf) { ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_copy_filter; return NGX_OK; }