Mercurial > hg > nginx
view src/http/v3/ngx_http_v3.c @ 9282:acb8548c00e9
HTTP/3: fixed dynamic table overflow.
While inserting a new entry into the dynamic table, first the entry is added,
and then older entries are evicted until table size is within capacity. After
the first step, the number of entries may temporarily exceed the maximum
calculated from capacity by one entry, which previously caused table overflow.
The easiest way to trigger the issue is to keep adding entries with empty names
and values until first eviction.
The issue was introduced by 987bee4363d1.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 28 May 2024 17:18:50 +0400 |
parents | 4939fd04737f |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static void ngx_http_v3_keepalive_handler(ngx_event_t *ev); static void ngx_http_v3_cleanup_session(void *data); ngx_int_t ngx_http_v3_init_session(ngx_connection_t *c) { ngx_pool_cleanup_t *cln; ngx_http_connection_t *hc; ngx_http_v3_session_t *h3c; hc = c->data; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http3 init session"); h3c = ngx_pcalloc(c->pool, sizeof(ngx_http_v3_session_t)); if (h3c == NULL) { goto failed; } h3c->http_connection = hc; ngx_queue_init(&h3c->blocked); h3c->keepalive.log = c->log; h3c->keepalive.data = c; h3c->keepalive.handler = ngx_http_v3_keepalive_handler; h3c->table.send_insert_count.log = c->log; h3c->table.send_insert_count.data = c; h3c->table.send_insert_count.handler = ngx_http_v3_inc_insert_count_handler; cln = ngx_pool_cleanup_add(c->pool, 0); if (cln == NULL) { goto failed; } cln->handler = ngx_http_v3_cleanup_session; cln->data = h3c; c->data = h3c; return NGX_OK; failed: ngx_log_error(NGX_LOG_ERR, c->log, 0, "failed to create http3 session"); return NGX_ERROR; } static void ngx_http_v3_keepalive_handler(ngx_event_t *ev) { ngx_connection_t *c; c = ev->data; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http3 keepalive handler"); ngx_http_v3_finalize_connection(c, NGX_HTTP_V3_ERR_NO_ERROR, "keepalive timeout"); } static void ngx_http_v3_cleanup_session(void *data) { ngx_http_v3_session_t *h3c = data; ngx_http_v3_cleanup_table(h3c); if (h3c->keepalive.timer_set) { ngx_del_timer(&h3c->keepalive); } if (h3c->table.send_insert_count.posted) { ngx_delete_posted_event(&h3c->table.send_insert_count); } } ngx_int_t ngx_http_v3_check_flood(ngx_connection_t *c) { ngx_http_v3_session_t *h3c; h3c = ngx_http_v3_get_session(c); if (h3c->total_bytes / 8 > h3c->payload_bytes + 1048576) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "http3 flood detected"); ngx_http_v3_finalize_connection(c, NGX_HTTP_V3_ERR_NO_ERROR, "HTTP/3 flood detected"); return NGX_ERROR; } return NGX_OK; }