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view src/http/v2/ngx_http_v2_table.c @ 7914:9cf043a5d9ca

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Request body: reading body buffering in filters. If a filter wants to buffer the request body during reading (for example, to check an external scanner), it can now do so. To make it possible, the code now checks rb->last_saved (introduced in the previous change) along with rb->rest == 0. Since in HTTP/2 this requires flow control to avoid overflowing the request body buffer, so filters which need buffering have to set the rb->filter_need_buffering flag on the first filter call. (Note that each filter is expected to call the next filter, so all filters will be able set the flag if needed.)
author Maxim Dounin <mdounin@mdounin.ru>
date Sun, 29 Aug 2021 22:22:02 +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;
}