Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_flv_module.c @ 7977:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +0300 |
parents | 99934aade555 |
children | 7a55311b0dc3 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static char *ngx_http_flv(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_flv_commands[] = { { ngx_string("flv"), NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS, ngx_http_flv, 0, 0, NULL }, ngx_null_command }; static u_char ngx_flv_header[] = "FLV\x1\x5\0\0\0\x9\0\0\0\0"; static ngx_http_module_t ngx_http_flv_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_flv_module = { NGX_MODULE_V1, &ngx_http_flv_module_ctx, /* module context */ ngx_http_flv_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_int_t ngx_http_flv_handler(ngx_http_request_t *r) { u_char *last; off_t start, len; size_t root; ngx_int_t rc; ngx_uint_t level, i; ngx_str_t path, value; ngx_log_t *log; ngx_buf_t *b; ngx_chain_t out[2]; ngx_open_file_info_t of; ngx_http_core_loc_conf_t *clcf; if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) { return NGX_HTTP_NOT_ALLOWED; } if (r->uri.data[r->uri.len - 1] == '/') { return NGX_DECLINED; } rc = ngx_http_discard_request_body(r); if (rc != NGX_OK) { return rc; } last = ngx_http_map_uri_to_path(r, &path, &root, 0); if (last == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } log = r->connection->log; path.len = last - path.data; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, log, 0, "http flv filename: \"%V\"", &path); clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); ngx_memzero(&of, sizeof(ngx_open_file_info_t)); of.read_ahead = clcf->read_ahead; of.directio = clcf->directio; of.valid = clcf->open_file_cache_valid; of.min_uses = clcf->open_file_cache_min_uses; of.errors = clcf->open_file_cache_errors; of.events = clcf->open_file_cache_events; if (ngx_http_set_disable_symlinks(r, clcf, &path, &of) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_open_cached_file(clcf->open_file_cache, &path, &of, r->pool) != NGX_OK) { switch (of.err) { case 0: return NGX_HTTP_INTERNAL_SERVER_ERROR; case NGX_ENOENT: case NGX_ENOTDIR: case NGX_ENAMETOOLONG: level = NGX_LOG_ERR; rc = NGX_HTTP_NOT_FOUND; break; case NGX_EACCES: #if (NGX_HAVE_OPENAT) case NGX_EMLINK: case NGX_ELOOP: #endif level = NGX_LOG_ERR; rc = NGX_HTTP_FORBIDDEN; break; default: level = NGX_LOG_CRIT; rc = NGX_HTTP_INTERNAL_SERVER_ERROR; break; } if (rc != NGX_HTTP_NOT_FOUND || clcf->log_not_found) { ngx_log_error(level, log, of.err, "%s \"%s\" failed", of.failed, path.data); } return rc; } if (!of.is_file) { if (ngx_close_file(of.fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, log, ngx_errno, ngx_close_file_n " \"%s\" failed", path.data); } return NGX_DECLINED; } r->root_tested = !r->error_page; start = 0; len = of.size; i = 1; if (r->args.len) { if (ngx_http_arg(r, (u_char *) "start", 5, &value) == NGX_OK) { start = ngx_atoof(value.data, value.len); if (start == NGX_ERROR || start >= len) { start = 0; } if (start) { len = sizeof(ngx_flv_header) - 1 + len - start; i = 0; } } } log->action = "sending flv to client"; r->headers_out.status = NGX_HTTP_OK; r->headers_out.content_length_n = len; r->headers_out.last_modified_time = of.mtime; if (ngx_http_set_etag(r) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_http_set_content_type(r) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (i == 0) { b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } b->pos = ngx_flv_header; b->last = ngx_flv_header + sizeof(ngx_flv_header) - 1; b->memory = 1; out[0].buf = b; out[0].next = &out[1]; } b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } b->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t)); if (b->file == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } r->allow_ranges = 1; rc = ngx_http_send_header(r); if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { return rc; } b->file_pos = start; b->file_last = of.size; b->in_file = b->file_last ? 1: 0; b->last_buf = (r == r->main) ? 1 : 0; b->last_in_chain = 1; b->file->fd = of.fd; b->file->name = path; b->file->log = log; b->file->directio = of.is_directio; out[1].buf = b; out[1].next = NULL; return ngx_http_output_filter(r, &out[i]); } static char * ngx_http_flv(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_core_loc_conf_t *clcf; clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module); clcf->handler = ngx_http_flv_handler; return NGX_CONF_OK; }