Mercurial > hg > nginx-quic
view src/stream/ngx_stream_map_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | ec10ce307dc0 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_uint_t hash_max_size; ngx_uint_t hash_bucket_size; } ngx_stream_map_conf_t; typedef struct { ngx_hash_keys_arrays_t keys; ngx_array_t *values_hash; #if (NGX_PCRE) ngx_array_t regexes; #endif ngx_stream_variable_value_t *default_value; ngx_conf_t *cf; unsigned hostnames:1; unsigned no_cacheable:1; } ngx_stream_map_conf_ctx_t; typedef struct { ngx_stream_map_t map; ngx_stream_complex_value_t value; ngx_stream_variable_value_t *default_value; ngx_uint_t hostnames; /* unsigned hostnames:1 */ } ngx_stream_map_ctx_t; static int ngx_libc_cdecl ngx_stream_map_cmp_dns_wildcards(const void *one, const void *two); static void *ngx_stream_map_create_conf(ngx_conf_t *cf); static char *ngx_stream_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_stream_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf); static ngx_command_t ngx_stream_map_commands[] = { { ngx_string("map"), NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2, ngx_stream_map_block, NGX_STREAM_MAIN_CONF_OFFSET, 0, NULL }, { ngx_string("map_hash_max_size"), NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_STREAM_MAIN_CONF_OFFSET, offsetof(ngx_stream_map_conf_t, hash_max_size), NULL }, { ngx_string("map_hash_bucket_size"), NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_STREAM_MAIN_CONF_OFFSET, offsetof(ngx_stream_map_conf_t, hash_bucket_size), NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_map_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ ngx_stream_map_create_conf, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_map_module = { NGX_MODULE_V1, &ngx_stream_map_module_ctx, /* module context */ ngx_stream_map_commands, /* module directives */ NGX_STREAM_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_stream_map_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { ngx_stream_map_ctx_t *map = (ngx_stream_map_ctx_t *) data; ngx_str_t val, str; ngx_stream_complex_value_t *cv; ngx_stream_variable_value_t *value; ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "stream map started"); if (ngx_stream_complex_value(s, &map->value, &val) != NGX_OK) { return NGX_ERROR; } if (map->hostnames && val.len > 0 && val.data[val.len - 1] == '.') { val.len--; } value = ngx_stream_map_find(s, &map->map, &val); if (value == NULL) { value = map->default_value; } if (!value->valid) { cv = (ngx_stream_complex_value_t *) value->data; if (ngx_stream_complex_value(s, cv, &str) != NGX_OK) { return NGX_ERROR; } v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->len = str.len; v->data = str.data; } else { *v = *value; } ngx_log_debug2(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "stream map: \"%V\" \"%v\"", &val, v); return NGX_OK; } static void * ngx_stream_map_create_conf(ngx_conf_t *cf) { ngx_stream_map_conf_t *mcf; mcf = ngx_palloc(cf->pool, sizeof(ngx_stream_map_conf_t)); if (mcf == NULL) { return NULL; } mcf->hash_max_size = NGX_CONF_UNSET_UINT; mcf->hash_bucket_size = NGX_CONF_UNSET_UINT; return mcf; } static char * ngx_stream_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_map_conf_t *mcf = conf; char *rv; ngx_str_t *value, name; ngx_conf_t save; ngx_pool_t *pool; ngx_hash_init_t hash; ngx_stream_map_ctx_t *map; ngx_stream_variable_t *var; ngx_stream_map_conf_ctx_t ctx; ngx_stream_compile_complex_value_t ccv; if (mcf->hash_max_size == NGX_CONF_UNSET_UINT) { mcf->hash_max_size = 2048; } if (mcf->hash_bucket_size == NGX_CONF_UNSET_UINT) { mcf->hash_bucket_size = ngx_cacheline_size; } else { mcf->hash_bucket_size = ngx_align(mcf->hash_bucket_size, ngx_cacheline_size); } map = ngx_pcalloc(cf->pool, sizeof(ngx_stream_map_ctx_t)); if (map == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &map->value; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } name = value[2]; if (name.data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &name); return NGX_CONF_ERROR; } name.len--; name.data++; var = ngx_stream_add_variable(cf, &name, NGX_STREAM_VAR_CHANGEABLE); if (var == NULL) { return NGX_CONF_ERROR; } var->get_handler = ngx_stream_map_variable; var->data = (uintptr_t) map; pool = ngx_create_pool(NGX_DEFAULT_POOL_SIZE, cf->log); if (pool == NULL) { return NGX_CONF_ERROR; } ctx.keys.pool = cf->pool; ctx.keys.temp_pool = pool; if (ngx_hash_keys_array_init(&ctx.keys, NGX_HASH_LARGE) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } ctx.values_hash = ngx_pcalloc(pool, sizeof(ngx_array_t) * ctx.keys.hsize); if (ctx.values_hash == NULL) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #if (NGX_PCRE) if (ngx_array_init(&ctx.regexes, cf->pool, 2, sizeof(ngx_stream_map_regex_t)) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #endif ctx.default_value = NULL; ctx.cf = &save; ctx.hostnames = 0; ctx.no_cacheable = 0; save = *cf; cf->pool = pool; cf->ctx = &ctx; cf->handler = ngx_stream_map; cf->handler_conf = conf; rv = ngx_conf_parse(cf, NULL); *cf = save; if (rv != NGX_CONF_OK) { ngx_destroy_pool(pool); return rv; } if (ctx.no_cacheable) { var->flags |= NGX_STREAM_VAR_NOCACHEABLE; } map->default_value = ctx.default_value ? ctx.default_value: &ngx_stream_variable_null_value; map->hostnames = ctx.hostnames; hash.key = ngx_hash_key_lc; hash.max_size = mcf->hash_max_size; hash.bucket_size = mcf->hash_bucket_size; hash.name = "map_hash"; hash.pool = cf->pool; if (ctx.keys.keys.nelts) { hash.hash = &map->map.hash.hash; hash.temp_pool = NULL; if (ngx_hash_init(&hash, ctx.keys.keys.elts, ctx.keys.keys.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } } if (ctx.keys.dns_wc_head.nelts) { ngx_qsort(ctx.keys.dns_wc_head.elts, (size_t) ctx.keys.dns_wc_head.nelts, sizeof(ngx_hash_key_t), ngx_stream_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_head.elts, ctx.keys.dns_wc_head.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_head = (ngx_hash_wildcard_t *) hash.hash; } if (ctx.keys.dns_wc_tail.nelts) { ngx_qsort(ctx.keys.dns_wc_tail.elts, (size_t) ctx.keys.dns_wc_tail.nelts, sizeof(ngx_hash_key_t), ngx_stream_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_tail.elts, ctx.keys.dns_wc_tail.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_tail = (ngx_hash_wildcard_t *) hash.hash; } #if (NGX_PCRE) if (ctx.regexes.nelts) { map->map.regex = ctx.regexes.elts; map->map.nregex = ctx.regexes.nelts; } #endif ngx_destroy_pool(pool); return rv; } static int ngx_libc_cdecl ngx_stream_map_cmp_dns_wildcards(const void *one, const void *two) { ngx_hash_key_t *first, *second; first = (ngx_hash_key_t *) one; second = (ngx_hash_key_t *) two; return ngx_dns_strcmp(first->key.data, second->key.data); } static char * ngx_stream_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf) { u_char *data; size_t len; ngx_int_t rv; ngx_str_t *value, v; ngx_uint_t i, key; ngx_stream_map_conf_ctx_t *ctx; ngx_stream_complex_value_t cv, *cvp; ngx_stream_variable_value_t *var, **vp; ngx_stream_compile_complex_value_t ccv; ctx = cf->ctx; value = cf->args->elts; if (cf->args->nelts == 1 && ngx_strcmp(value[0].data, "hostnames") == 0) { ctx->hostnames = 1; return NGX_CONF_OK; } if (cf->args->nelts == 1 && ngx_strcmp(value[0].data, "volatile") == 0) { ctx->no_cacheable = 1; return NGX_CONF_OK; } if (cf->args->nelts != 2) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid number of the map parameters"); return NGX_CONF_ERROR; } if (ngx_strcmp(value[0].data, "include") == 0) { return ngx_conf_include(cf, dummy, conf); } key = 0; for (i = 0; i < value[1].len; i++) { key = ngx_hash(key, value[1].data[i]); } key %= ctx->keys.hsize; vp = ctx->values_hash[key].elts; if (vp) { for (i = 0; i < ctx->values_hash[key].nelts; i++) { if (vp[i]->valid) { data = vp[i]->data; len = vp[i]->len; } else { cvp = (ngx_stream_complex_value_t *) vp[i]->data; data = cvp->value.data; len = cvp->value.len; } if (value[1].len != len) { continue; } if (ngx_strncmp(value[1].data, data, len) == 0) { var = vp[i]; goto found; } } } else { if (ngx_array_init(&ctx->values_hash[key], cf->pool, 4, sizeof(ngx_stream_variable_value_t *)) != NGX_OK) { return NGX_CONF_ERROR; } } var = ngx_palloc(ctx->keys.pool, sizeof(ngx_stream_variable_value_t)); if (var == NULL) { return NGX_CONF_ERROR; } v.len = value[1].len; v.data = ngx_pstrdup(ctx->keys.pool, &value[1]); if (v.data == NULL) { return NGX_CONF_ERROR; } ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = ctx->cf; ccv.value = &v; ccv.complex_value = &cv; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } if (cv.lengths != NULL) { cvp = ngx_palloc(ctx->keys.pool, sizeof(ngx_stream_complex_value_t)); if (cvp == NULL) { return NGX_CONF_ERROR; } *cvp = cv; var->len = 0; var->data = (u_char *) cvp; var->valid = 0; } else { var->len = v.len; var->data = v.data; var->valid = 1; } var->no_cacheable = 0; var->not_found = 0; vp = ngx_array_push(&ctx->values_hash[key]); if (vp == NULL) { return NGX_CONF_ERROR; } *vp = var; found: if (ngx_strcmp(value[0].data, "default") == 0) { if (ctx->default_value) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate default map parameter"); return NGX_CONF_ERROR; } ctx->default_value = var; return NGX_CONF_OK; } #if (NGX_PCRE) if (value[0].len && value[0].data[0] == '~') { ngx_regex_compile_t rc; ngx_stream_map_regex_t *regex; u_char errstr[NGX_MAX_CONF_ERRSTR]; regex = ngx_array_push(&ctx->regexes); if (regex == NULL) { return NGX_CONF_ERROR; } value[0].len--; value[0].data++; ngx_memzero(&rc, sizeof(ngx_regex_compile_t)); if (value[0].data[0] == '*') { value[0].len--; value[0].data++; rc.options = NGX_REGEX_CASELESS; } rc.pattern = value[0]; rc.err.len = NGX_MAX_CONF_ERRSTR; rc.err.data = errstr; regex->regex = ngx_stream_regex_compile(ctx->cf, &rc); if (regex->regex == NULL) { return NGX_CONF_ERROR; } regex->value = var; return NGX_CONF_OK; } #endif if (value[0].len && value[0].data[0] == '\\') { value[0].len--; value[0].data++; } rv = ngx_hash_add_key(&ctx->keys, &value[0], var, (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0); if (rv == NGX_OK) { return NGX_CONF_OK; } if (rv == NGX_DECLINED) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid hostname or wildcard \"%V\"", &value[0]); } if (rv == NGX_BUSY) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "conflicting parameter \"%V\"", &value[0]); } return NGX_CONF_ERROR; }