Mercurial > hg > nginx
view src/http/v2/ngx_http_v2_table.c @ 7100:12cadc4669a7
HTTP/2: signal 0-byte HPACK's dynamic table size.
This change lets NGINX talk to clients with SETTINGS_HEADER_TABLE_SIZE
smaller than the default 4KB. Previously, NGINX would ACK the SETTINGS
frame with a small dynamic table size, but it would never send dynamic
table size update, leading to a connection-level COMPRESSION_ERROR.
Also, it allows clients to release 4KB of memory per connection, since
NGINX doesn't use HPACK's dynamic table when encoding headers, however
clients had to maintain it, since NGINX never signaled that it doesn't
use it.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
author | Piotr Sikora <piotrsikora@google.com> |
---|---|
date | Wed, 30 Aug 2017 14:52:11 -0700 |
parents | 257b51c37c5a |
children | d4b031cf32cf |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_V2_TABLE_SIZE 4096 static ngx_int_t ngx_http_v2_table_account(ngx_http_v2_connection_t *h2c, size_t size); static ngx_http_v2_header_t ngx_http_v2_static_table[] = { { ngx_string(":authority"), ngx_string("") }, { ngx_string(":method"), ngx_string("GET") }, { ngx_string(":method"), ngx_string("POST") }, { ngx_string(":path"), ngx_string("/") }, { ngx_string(":path"), ngx_string("/index.html") }, { ngx_string(":scheme"), ngx_string("http") }, { ngx_string(":scheme"), ngx_string("https") }, { ngx_string(":status"), ngx_string("200") }, { ngx_string(":status"), ngx_string("204") }, { ngx_string(":status"), ngx_string("206") }, { ngx_string(":status"), ngx_string("304") }, { ngx_string(":status"), ngx_string("400") }, { ngx_string(":status"), ngx_string("404") }, { ngx_string(":status"), ngx_string("500") }, { ngx_string("accept-charset"), ngx_string("") }, { ngx_string("accept-encoding"), ngx_string("gzip, deflate") }, { ngx_string("accept-language"), ngx_string("") }, { ngx_string("accept-ranges"), ngx_string("") }, { ngx_string("accept"), ngx_string("") }, { ngx_string("access-control-allow-origin"), ngx_string("") }, { ngx_string("age"), ngx_string("") }, { ngx_string("allow"), ngx_string("") }, { ngx_string("authorization"), ngx_string("") }, { ngx_string("cache-control"), ngx_string("") }, { ngx_string("content-disposition"), ngx_string("") }, { ngx_string("content-encoding"), ngx_string("") }, { ngx_string("content-language"), ngx_string("") }, { ngx_string("content-length"), ngx_string("") }, { ngx_string("content-location"), ngx_string("") }, { ngx_string("content-range"), ngx_string("") }, { ngx_string("content-type"), ngx_string("") }, { ngx_string("cookie"), ngx_string("") }, { ngx_string("date"), ngx_string("") }, { ngx_string("etag"), ngx_string("") }, { ngx_string("expect"), ngx_string("") }, { ngx_string("expires"), ngx_string("") }, { ngx_string("from"), ngx_string("") }, { ngx_string("host"), ngx_string("") }, { ngx_string("if-match"), ngx_string("") }, { ngx_string("if-modified-since"), ngx_string("") }, { ngx_string("if-none-match"), ngx_string("") }, { ngx_string("if-range"), ngx_string("") }, { ngx_string("if-unmodified-since"), ngx_string("") }, { ngx_string("last-modified"), ngx_string("") }, { ngx_string("link"), ngx_string("") }, { ngx_string("location"), ngx_string("") }, { ngx_string("max-forwards"), ngx_string("") }, { ngx_string("proxy-authenticate"), ngx_string("") }, { ngx_string("proxy-authorization"), ngx_string("") }, { ngx_string("range"), ngx_string("") }, { ngx_string("referer"), ngx_string("") }, { ngx_string("refresh"), ngx_string("") }, { ngx_string("retry-after"), ngx_string("") }, { ngx_string("server"), ngx_string("") }, { ngx_string("set-cookie"), ngx_string("") }, { ngx_string("strict-transport-security"), ngx_string("") }, { ngx_string("transfer-encoding"), ngx_string("") }, { ngx_string("user-agent"), ngx_string("") }, { ngx_string("vary"), ngx_string("") }, { ngx_string("via"), ngx_string("") }, { ngx_string("www-authenticate"), ngx_string("") }, }; #define NGX_HTTP_V2_STATIC_TABLE_ENTRIES \ (sizeof(ngx_http_v2_static_table) \ / sizeof(ngx_http_v2_header_t)) ngx_int_t ngx_http_v2_get_indexed_header(ngx_http_v2_connection_t *h2c, ngx_uint_t index, ngx_uint_t name_only) { u_char *p; size_t rest; ngx_http_v2_header_t *entry; if (index == 0) { ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent invalid hpack table index 0"); return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 get indexed %s: %ui", name_only ? "header" : "header name", index); index--; if (index < NGX_HTTP_V2_STATIC_TABLE_ENTRIES) { h2c->state.header = ngx_http_v2_static_table[index]; return NGX_OK; } index -= NGX_HTTP_V2_STATIC_TABLE_ENTRIES; if (index < h2c->hpack.added - h2c->hpack.deleted) { index = (h2c->hpack.added - index - 1) % h2c->hpack.allocated; entry = h2c->hpack.entries[index]; p = ngx_pnalloc(h2c->state.pool, entry->name.len + 1); if (p == NULL) { return NGX_ERROR; } h2c->state.header.name.len = entry->name.len; h2c->state.header.name.data = p; rest = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - entry->name.data; if (entry->name.len > rest) { p = ngx_cpymem(p, entry->name.data, rest); p = ngx_cpymem(p, h2c->hpack.storage, entry->name.len - rest); } else { p = ngx_cpymem(p, entry->name.data, entry->name.len); } *p = '\0'; if (name_only) { return NGX_OK; } p = ngx_pnalloc(h2c->state.pool, entry->value.len + 1); if (p == NULL) { return NGX_ERROR; } h2c->state.header.value.len = entry->value.len; h2c->state.header.value.data = p; rest = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - entry->value.data; if (entry->value.len > rest) { p = ngx_cpymem(p, entry->value.data, rest); p = ngx_cpymem(p, h2c->hpack.storage, entry->value.len - rest); } else { p = ngx_cpymem(p, entry->value.data, entry->value.len); } *p = '\0'; return NGX_OK; } ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent out of bound hpack table index: %ui", index); return NGX_ERROR; } ngx_int_t ngx_http_v2_add_header(ngx_http_v2_connection_t *h2c, ngx_http_v2_header_t *header) { size_t avail; ngx_uint_t index; ngx_http_v2_header_t *entry, **entries; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 add header to hpack table: \"%V: %V\"", &header->name, &header->value); if (h2c->hpack.entries == NULL) { h2c->hpack.allocated = 64; h2c->hpack.size = NGX_HTTP_V2_TABLE_SIZE; h2c->hpack.free = NGX_HTTP_V2_TABLE_SIZE; h2c->hpack.entries = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t *) * h2c->hpack.allocated); if (h2c->hpack.entries == NULL) { return NGX_ERROR; } h2c->hpack.storage = ngx_palloc(h2c->connection->pool, h2c->hpack.free); if (h2c->hpack.storage == NULL) { return NGX_ERROR; } h2c->hpack.pos = h2c->hpack.storage; } if (ngx_http_v2_table_account(h2c, header->name.len + header->value.len) != NGX_OK) { return NGX_OK; } if (h2c->hpack.reused == h2c->hpack.deleted) { entry = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t)); if (entry == NULL) { return NGX_ERROR; } } else { entry = h2c->hpack.entries[h2c->hpack.reused++ % h2c->hpack.allocated]; } avail = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - h2c->hpack.pos; entry->name.len = header->name.len; entry->name.data = h2c->hpack.pos; if (avail >= header->name.len) { h2c->hpack.pos = ngx_cpymem(h2c->hpack.pos, header->name.data, header->name.len); } else { ngx_memcpy(h2c->hpack.pos, header->name.data, avail); h2c->hpack.pos = ngx_cpymem(h2c->hpack.storage, header->name.data + avail, header->name.len - avail); avail = NGX_HTTP_V2_TABLE_SIZE; } avail -= header->name.len; entry->value.len = header->value.len; entry->value.data = h2c->hpack.pos; if (avail >= header->value.len) { h2c->hpack.pos = ngx_cpymem(h2c->hpack.pos, header->value.data, header->value.len); } else { ngx_memcpy(h2c->hpack.pos, header->value.data, avail); h2c->hpack.pos = ngx_cpymem(h2c->hpack.storage, header->value.data + avail, header->value.len - avail); } if (h2c->hpack.allocated == h2c->hpack.added - h2c->hpack.deleted) { entries = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t *) * (h2c->hpack.allocated + 64)); if (entries == NULL) { return NGX_ERROR; } index = h2c->hpack.deleted % h2c->hpack.allocated; ngx_memcpy(entries, &h2c->hpack.entries[index], (h2c->hpack.allocated - index) * sizeof(ngx_http_v2_header_t *)); ngx_memcpy(&entries[h2c->hpack.allocated - index], h2c->hpack.entries, index * sizeof(ngx_http_v2_header_t *)); (void) ngx_pfree(h2c->connection->pool, h2c->hpack.entries); h2c->hpack.entries = entries; h2c->hpack.added = h2c->hpack.allocated; h2c->hpack.deleted = 0; h2c->hpack.reused = 0; h2c->hpack.allocated += 64; } h2c->hpack.entries[h2c->hpack.added++ % h2c->hpack.allocated] = entry; return NGX_OK; } static ngx_int_t ngx_http_v2_table_account(ngx_http_v2_connection_t *h2c, size_t size) { ngx_http_v2_header_t *entry; size += 32; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 hpack table account: %uz free:%uz", size, h2c->hpack.free); if (size <= h2c->hpack.free) { h2c->hpack.free -= size; return NGX_OK; } if (size > h2c->hpack.size) { h2c->hpack.deleted = h2c->hpack.added; h2c->hpack.free = h2c->hpack.size; return NGX_DECLINED; } do { entry = h2c->hpack.entries[h2c->hpack.deleted++ % h2c->hpack.allocated]; h2c->hpack.free += 32 + entry->name.len + entry->value.len; } while (size > h2c->hpack.free); h2c->hpack.free -= size; return NGX_OK; } ngx_int_t ngx_http_v2_table_size(ngx_http_v2_connection_t *h2c, size_t size) { ssize_t needed; ngx_http_v2_header_t *entry; if (size > NGX_HTTP_V2_TABLE_SIZE) { ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent invalid table size update: %uz", size); return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 new hpack table size: %uz was:%uz", size, h2c->hpack.size); needed = h2c->hpack.size - size; while (needed > (ssize_t) h2c->hpack.free) { entry = h2c->hpack.entries[h2c->hpack.deleted++ % h2c->hpack.allocated]; h2c->hpack.free += 32 + entry->name.len + entry->value.len; } h2c->hpack.size = size; h2c->hpack.free -= needed; return NGX_OK; }