Mercurial > hg > nginx-quic
view src/http/ngx_http_copy_filter_module.c @ 4964:2464ccebdb52
Upstream: fixed SIGSEGV with the "if" directive.
Configuration like
location / {
set $true 1;
if ($true) {
proxy_pass http://backend;
}
if ($true) {
# nothing
}
}
resulted in segmentation fault due to NULL pointer dereference as the
upstream configuration wasn't initialized in an implicit location created
by the last if(), but the r->content_handler was set due to first if().
Instead of committing a suicide by dereferencing a NULL pointer, return
500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better
fix would be to avoid such cases by fixing the "if" directive handling,
but it's out of scope of this patch.
Prodded by Piotr Sikora.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 13 Dec 2012 16:05:59 +0000 |
parents | 586969d972b9 |
children | d39a69427056 |
line wrap: on
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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 void ngx_http_copy_aio_sendfile_event_handler(ngx_event_t *ev); #endif #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) { if (clcf->aio) { ctx->aio_handler = ngx_http_copy_aio_handler; } #if (NGX_HAVE_AIO_SENDFILE) c->aio_sendfile = (clcf->aio == NGX_HTTP_AIO_SENDFILE); #endif } #endif if (in && in->buf && ngx_buf_size(in->buf)) { r->request_output = 1; } } #if (NGX_HAVE_FILE_AIO) ctx->aio = r->aio; #endif for ( ;; ) { 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); #if (NGX_HAVE_FILE_AIO && NGX_HAVE_AIO_SENDFILE) if (c->busy_sendfile) { ssize_t n; off_t offset; ngx_file_t *file; ngx_http_ephemeral_t *e; if (r->aio) { c->busy_sendfile = NULL; return rc; } file = c->busy_sendfile->file; offset = c->busy_sendfile->file_pos; if (file->aio) { c->aio_sendfile = (offset != file->aio->last_offset); file->aio->last_offset = offset; if (c->aio_sendfile == 0) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "sendfile(%V) returned busy again", &file->name); } } c->busy_sendfile = NULL; e = (ngx_http_ephemeral_t *) &r->uri_start; n = ngx_file_aio_read(file, &e->aio_preload, 1, offset, r->pool); if (n > 0) { in = NULL; continue; } rc = n; if (rc == NGX_AGAIN) { file->aio->data = r; file->aio->handler = ngx_http_copy_aio_sendfile_event_handler; r->main->blocked++; r->aio = 1; } } #endif 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_http_request_t *r; aio = ev->data; r = aio->data; r->main->blocked--; r->aio = 0; r->connection->write->handler(r->connection->write); } #if (NGX_HAVE_AIO_SENDFILE) 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 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, 1, 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; }