view src/http/v2/ngx_http_v2_table.c @ 8006:32b0ba4855a6

HTTP/2: made it possible to flush response headers (ticket #1743). Response headers can be buffered in the SSL buffer. But stream's fake connection buffered flag did not reflect this, so any attempts to flush the buffer without sending additional data were stopped by the write filter. It does not seem to be possible to reflect this in fc->buffered though, as we never known if main connection's c->buffered corresponds to the particular stream or not. As such, fc->buffered might prevent request finalization due to sending data on some other stream. Fix is to implement handling of flush buffers when the c->need_flush_buf flag is set, similarly to the existing last buffer handling. The same flag is now used for UDP sockets in the stream module instead of explicit checking of c->type.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 03 Feb 2022 01:44:38 +0300
parents 87e9e4aabf1b
children
line wrap: on
line source


/*
 * 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_str_t *
ngx_http_v2_get_static_name(ngx_uint_t index)
{
    return &ngx_http_v2_static_table[index - 1].name;
}


ngx_str_t *
ngx_http_v2_get_static_value(ngx_uint_t index)
{
    return &ngx_http_v2_static_table[index - 1].value;
}


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 ? "name" : "header", 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 table add: \"%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 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;
}