libmicrohttpd2

HTTP server C library (MHD 2.x, alpha)
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h2_proc_conn.c (6229B)


      1 /* SPDX-License-Identifier: LGPL-2.1-or-later OR (GPL-2.0-or-later WITH eCos-exception-2.0) */
      2 /*
      3   This file is part of GNU libmicrohttpd.
      4   Copyright (C) 2025 Evgeny Grin (Karlson2k)
      5 
      6   GNU libmicrohttpd is free software; you can redistribute it and/or
      7   modify it under the terms of the GNU Lesser General Public
      8   License as published by the Free Software Foundation; either
      9   version 2.1 of the License, or (at your option) any later version.
     10 
     11   GNU libmicrohttpd is distributed in the hope that it will be useful,
     12   but WITHOUT ANY WARRANTY; without even the implied warranty of
     13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14   Lesser General Public License for more details.
     15 
     16   Alternatively, you can redistribute GNU libmicrohttpd and/or
     17   modify it under the terms of the GNU General Public License as
     18   published by the Free Software Foundation; either version 2 of
     19   the License, or (at your option) any later version, together
     20   with the eCos exception, as follows:
     21 
     22     As a special exception, if other files instantiate templates or
     23     use macros or inline functions from this file, or you compile this
     24     file and link it with other works to produce a work based on this
     25     file, this file does not by itself cause the resulting work to be
     26     covered by the GNU General Public License. However the source code
     27     for this file must still be made available in accordance with
     28     section (3) of the GNU General Public License v2.
     29 
     30     This exception does not invalidate any other reasons why a work
     31     based on this file might be covered by the GNU General Public
     32     License.
     33 
     34   You should have received copies of the GNU Lesser General Public
     35   License and the GNU General Public License along with this library;
     36   if not, see <https://www.gnu.org/licenses/>.
     37 */
     38 
     39 /**
     40  * @file src/mhd2/h2/h2_proc_conn.c
     41  * @brief  Implementation of HTTP/2 connection processing functions
     42  * @author Karlson2k (Evgeny Grin)
     43  */
     44 
     45 #include "mhd_sys_options.h"
     46 
     47 #include "sys_bool_type.h"
     48 #include "sys_base_types.h"
     49 
     50 #include "mhd_assert.h"
     51 #include "mhd_unreachable.h"
     52 
     53 #include "mhd_connection.h"
     54 
     55 #include "h2_frame_types.h"
     56 
     57 #include "h2_frame_init.h"
     58 #include "h2_frame_codec.h"
     59 
     60 #include "h2_proc_settings.h"
     61 #include "h2_conn_streams.h"
     62 #include "h2_proc_out.h"
     63 
     64 #include "h2_proc_conn.h"
     65 
     66 
     67 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ bool
     68 mhd_h2_conn_process_first_fr (struct MHD_Connection *restrict c)
     69 {
     70   union mhd_H2FrameUnion first_fr;
     71   struct mhd_Buffer payload;
     72   enum mhd_H2FrameDecodeResult dec_res;
     73   bool ret;
     74 
     75   mhd_assert (mhd_C_IS_HTTP2 (c));
     76   mhd_assert (! c->h2.state.init.got_setns);
     77 
     78   dec_res = mhd_h2_frame_decode (c->read_buffer_offset - c->h2.buff.r_cur_frame,
     79                                  (uint8_t *) c->read_buffer
     80                                  + c->h2.buff.r_cur_frame,
     81                                  mhd_H2_STNG_DEF_MAX_FRAME_SIZE, /* Settings are not yet ACKed */
     82                                  &first_fr,
     83                                  &payload);
     84   if (mhd_H2_FRAME_DEC_ERR_IS_HARD (dec_res))
     85   {
     86     mhd_h2_conn_finish (c,
     87                         mhd_H2_F_DEC_CONN_ERR_F_SIZE == dec_res ?
     88                         mhd_H2_ERR_FRAME_SIZE_ERROR : mhd_H2_ERR_PROTOCOL_ERROR,
     89                         true);
     90     return false;
     91   }
     92 
     93   if (mhd_H2_F_DEC_OK != dec_res)
     94     return false;       /* Not yet complete */
     95 
     96   if ((mhd_H2_FRAME_IDS_SETTINGS_ID != first_fr.selector.type) ||
     97       (first_fr.settings.ack))
     98   {
     99     mhd_h2_conn_finish (c,
    100                         mhd_H2_ERR_PROTOCOL_ERROR,
    101                         true);
    102     return false;
    103   }
    104 
    105   ret = mhd_h2_proc_first_settings (c,
    106                                     &payload);
    107 
    108   c->h2.buff.r_cur_frame += mhd_h2_frame_get_total_size (&first_fr);
    109 
    110   return ret;
    111 }
    112 
    113 
    114 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ bool
    115 mhd_h2_conn_process_in_goaway (struct MHD_Connection *restrict c,
    116                                uint_least32_t last_stream_id,
    117                                enum mhd_H2ErrorCode err)
    118 {
    119   c->h2.state.recvd_goaway.occurred = true;
    120   c->h2.state.recvd_goaway.code = err;
    121   c->h2.peer.stream_id_limit = last_stream_id;
    122 
    123   // TODO: close all streams with higher IDs
    124 
    125   return true;
    126 }
    127 
    128 
    129 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ bool
    130 mhd_h2_conn_update_stream_init_window (struct MHD_Connection *restrict c,
    131                                        uint_least32_t init_wind_size)
    132 {
    133   mhd_assert (0x7FFFFFFFu >= init_wind_size);
    134   (void) c; // TODO: change window in all streams
    135 
    136   c->h2.peer.stream_init_win_sz = init_wind_size;
    137   return true;
    138 }
    139 
    140 
    141 static MHD_FN_PAR_NONNULL_ALL_ bool
    142 conn_win_update (struct MHD_Connection *restrict c)
    143 {
    144   mhd_assert (0 <= c->h2.state.recv_window);
    145   /* Dumb algorithm: if receive windows is less than three quarters of the full
    146    * window size, then bump to the full size. */
    147   if ((c->h2.rcv_cfg.conn_full_win_sz - c->h2.rcv_cfg.conn_full_win_sz / 4) >=
    148       (uint_least32_t) c->h2.state.recv_window)
    149   {
    150     const uint_least32_t incr =
    151       (uint_least32_t)
    152       (c->h2.rcv_cfg.conn_full_win_sz
    153        - (uint_least32_t) c->h2.state.recv_window);
    154     mhd_assert (0x7FFFFFFFu >= incr);
    155     if (! mhd_h2_q_window_update (c,
    156                                   0u,
    157                                   incr))
    158       return false;
    159     c->h2.state.recv_window = (int_least32_t) c->h2.rcv_cfg.conn_full_win_sz;
    160   }
    161   return true;
    162 }
    163 
    164 
    165 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ bool
    166 mhd_h2_conn_process_changes (struct MHD_Connection *restrict c)
    167 {
    168   if (! conn_win_update (c))
    169     return false;
    170 
    171   if (! mhd_h2_conn_maintain_streams_all (c))
    172     return false;
    173 
    174   return true;
    175 }
    176 
    177 
    178 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ bool
    179 mhd_h2_conn_finish (struct MHD_Connection *restrict c,
    180                     enum mhd_H2ErrorCode err,
    181                     bool forced)
    182 {
    183   if (! mhd_h2_q_goaway (c,
    184                          err))
    185   {
    186     if (! forced)
    187       return false;
    188 
    189     c->h2.state.sent_goaway.occurred = true;
    190     c->h2.state.sent_goaway.code = (uint_least32_t) err;
    191 
    192     c->h_layer.state = mhd_HTTP_LAYER_BROKEN;
    193     return true;
    194   }
    195 
    196   c->h2.state.sent_goaway.occurred = true;
    197   c->h2.state.sent_goaway.code = (uint_least32_t) err;
    198 
    199   c->h_layer.state = mhd_HTTP_LAYER_CLOSING;
    200   return true;
    201 }