http_send.c

   1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file http_send.c paraslash's http sender */
   4
   5 #include <netinet/in.h>
   6 #include <sys/socket.h>
   7 #include <regex.h>
   8 #include <sys/types.h>
   9 #include <arpa/inet.h>
  10 #include <sys/un.h>
  11 #include <netdb.h>
  12 #include <lopsub.h>
  13
  14 #include "server.lsg.h"
  15 #include "para.h"
  16 #include "error.h"
  17 #include "string.h"
  18 #include "afh.h"
  19 #include "net.h"
  20 #include "server.h"
  21 #include "http.h"
  22 #include "list.h"
  23 #include "send.h"
  24 #include "sched.h"
  25 #include "vss.h"
  26 #include "close_on_fork.h"
  27 #include "fd.h"
  28 #include "chunk_queue.h"
  29
  30 /** Message sent to clients that do not send a valid get request. */
  31 #define HTTP_ERR_MSG "HTTP/1.0 400 Bad Request\n"
  32
  33 /** The possible states of a client from the server's POV. */
  34 enum http_client_status {
  35         /** We accepted the connection on the tcp socket. */
  36         HTTP_CONNECTED,
  37         /** Successfully received the get request. */
  38         HTTP_GOT_GET_REQUEST,
  39         /** Connection is ready for sending audio data. */
  40         HTTP_STREAMING,
  41         /** We didn't receive a valid get request. */
  42         HTTP_INVALID_GET_REQUEST
  43 };
  44
  45 /** For each connected client, a structure of this type is maintained. */
  46 struct private_http_sender_data {
  47         /** The current state of this client. */
  48         enum http_client_status status;
  49 };
  50
  51 static struct sender_status http_sender_status, *hss = &http_sender_status;
  52
  53 static int http_send_msg(struct sender_client *sc, const char *msg)
  54 {
  55         int ret = write_buffer(sc->fd, msg);
  56
  57         if (ret < 0)
  58                 shutdown_client(sc, hss);
  59         return ret;
  60 }
  61
  62 static void http_send_ok_msg(struct sender_client *sc)
  63 {
  64         PARA_INFO_LOG("sending http ok message to fd %d\n", sc->fd);
  65         http_send_msg(sc, HTTP_OK_MSG);
  66 }
  67
  68 static int http_send_err_msg(struct sender_client *sc)
  69 {
  70         PARA_NOTICE_LOG("sending bad request message to fd %d\n", sc->fd);
  71         return http_send_msg(sc, HTTP_ERR_MSG);
  72 }
  73
  74 static void http_shutdown_clients(void)
  75 {
  76         shutdown_clients(hss);
  77 }
  78
  79 static void http_shutdown(void)
  80 {
  81         http_shutdown_clients();
  82         generic_acl_deplete(&hss->acl);
  83 }
  84
  85 static int queue_chunk_or_shutdown(struct sender_client *sc,
  86                 struct sender_status *ss, const char *buf, size_t num_bytes)
  87 {
  88         int ret = cq_enqueue(sc->cq, buf, num_bytes);
  89         if (ret < 0)
  90                 shutdown_client(sc, ss);
  91         return ret;
  92 }
  93
  94 /**
  95  * Send one chunk of audio data to a connected client.
  96  *
  97  * \param sc The client.
  98  * \param ss The sender.
  99  * \param current_chunk The number of the chunk to write.
 100  * \param buf The data to write.
 101  * \param len The number of bytes of \a buf.
 102  * \param header_buf The audio file header.
 103  * \param header_len The number of bytes of \a header_buf.
 104  *
 105  * On errors, the client is shut down. If only a part of the buffer could be
 106  * written, the remainder is put into the chunk queue for that client.
 107  */
 108 static void http_send_chunk(struct sender_client *sc, struct sender_status *ss,
 109                 long unsigned current_chunk, const char *buf, size_t len,
 110                 const char *header_buf, size_t header_len)
 111 {
 112         int ret;
 113
 114         if (!sc->header_sent && current_chunk) {
 115                 if (header_buf && header_len > 0) {
 116                         ret = queue_chunk_or_shutdown(sc, ss, header_buf, header_len);
 117                         if (ret < 0)
 118                                 goto out;
 119                 }
 120         }
 121         sc->header_sent = 1;
 122         ret = send_queued_chunks(sc->fd, sc->cq);
 123         if (ret < 0) {
 124                 shutdown_client(sc, ss);
 125                 goto out;
 126         }
 127         if (!len)
 128                 goto out;
 129         if (!ret) { /* still data left in the queue */
 130                 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
 131                 goto out;
 132         }
 133         ret = xwrite(sc->fd, buf, len);
 134         if (ret < 0) {
 135                 shutdown_client(sc, ss);
 136                 goto out;
 137         }
 138         if (ret != len)
 139                 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
 140 out:
 141         if (ret < 0)
 142                 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
 143 }
 144
 145 static void http_send(long unsigned current_chunk,
 146         __a_unused long unsigned chunks_sent, const char *buf, size_t len,
 147         const char *header_buf, size_t header_len)
 148 {
 149         struct sender_client *sc, *tmp;
 150
 151         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 152                 struct private_http_sender_data *phsd = sc->private_data;
 153
 154                 if (phsd->status == HTTP_STREAMING)
 155                         http_send_chunk(sc, hss, current_chunk, buf, len,
 156                                    header_buf, header_len);
 157         }
 158 }
 159
 160 static void http_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 161 {
 162         struct sender_client *sc, *tmp;
 163         struct private_http_sender_data *phsd;
 164         int ret;
 165
 166         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 167                 phsd = sc->private_data;
 168                 switch (phsd->status) {
 169                 case HTTP_STREAMING: /* nothing to do */
 170                         break;
 171                 case HTTP_CONNECTED: /* need to recv get request */
 172                         ret = read_pattern(sc->fd, HTTP_GET_MSG, MAXLINE, rfds);
 173                         if (ret < 0)
 174                                 phsd->status = HTTP_INVALID_GET_REQUEST;
 175                         else if (ret > 0) {
 176                                 phsd->status = HTTP_GOT_GET_REQUEST;
 177                                 PARA_INFO_LOG("received get request\n");
 178                         }
 179                         break;
 180                 case HTTP_GOT_GET_REQUEST: /* need to send ok msg */
 181                         phsd->status = HTTP_STREAMING;
 182                         http_send_ok_msg(sc);
 183                         break;
 184                 case HTTP_INVALID_GET_REQUEST: /* need to send err msg */
 185                         if (http_send_err_msg(sc) >= 0)
 186                                 shutdown_client(sc, hss);
 187                         break;
 188                 }
 189         }
 190         sc = accept_sender_client(hss, rfds);
 191         if (!sc)
 192                 return;
 193         phsd = para_malloc(sizeof(*phsd));
 194         sc->private_data = phsd;
 195         phsd->status = HTTP_CONNECTED;
 196 }
 197
 198 static void http_pre_select(int *max_fileno, fd_set *rfds, fd_set *wfds)
 199 {
 200         struct sender_client *sc, *tmp;
 201         unsigned n;
 202
 203         FOR_EACH_LISTEN_FD(n, hss) {
 204                 if (hss->listen_fds[n] < 0)
 205                         continue;
 206                 para_fd_set(hss->listen_fds[n], rfds, max_fileno);
 207         }
 208         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 209                 struct private_http_sender_data *phsd = sc->private_data;
 210                 if (phsd->status == HTTP_CONNECTED) /* need to recv get request */
 211                         para_fd_set(sc->fd, rfds, max_fileno);
 212                 if (phsd->status == HTTP_GOT_GET_REQUEST ||
 213                                 phsd->status == HTTP_INVALID_GET_REQUEST)
 214                         para_fd_set(sc->fd, wfds, max_fileno);
 215         }
 216 }
 217
 218 static int http_com_on(__a_unused struct sender_command_data *scd)
 219 {
 220         generic_com_on(hss, IPPROTO_TCP);
 221         return 1;
 222 }
 223
 224 static int http_com_off(__a_unused struct sender_command_data *scd)
 225 {
 226         generic_com_off(hss);
 227         return 1;
 228 }
 229
 230 static int http_com_deny(struct sender_command_data *scd)
 231 {
 232         generic_com_deny(scd, hss);
 233         return 1;
 234 }
 235
 236 static int http_com_allow(struct sender_command_data *scd)
 237 {
 238         generic_com_allow(scd, hss);
 239         return 1;
 240 }
 241
 242 static char *http_status(void)
 243 {
 244         return generic_sender_status(hss, "http");
 245 }
 246
 247 /*
 248  * Initialize the client list and the access control list, and optionally
 249  * listen on the tcp port.
 250  */
 251 static void http_send_init(void)
 252 {
 253         init_sender_status(hss, OPT_RESULT(HTTP_ACCESS),
 254                 OPT_RESULT(HTTP_LISTEN_ADDRESS),
 255                 OPT_UINT32_VAL(HTTP_PORT), OPT_UINT32_VAL(HTTP_MAX_CLIENTS),
 256                 OPT_GIVEN(HTTP_DEFAULT_DENY));
 257         if (OPT_GIVEN(HTTP_NO_AUTOSTART))
 258                 return;
 259         generic_com_on(hss, IPPROTO_TCP);
 260 }
 261
 262 /**
 263  * The HTTP sender.
 264  *
 265  * This is the only sender which does not FEC-encode the stream. This is not
 266  * necessary because HTTP sits on top of TCP, a reliable transport which
 267  * retransmits lost packets automatically. The sender employs per-client queues
 268  * which queue chunks of audio data if they can not be sent immediately because
 269  * the write operation would block. Most methods of the sender are implemented
 270  * as wrappers for the generic functions defined in \ref send_common.c.
 271  */
 272 const struct sender http_sender = {
 273         .name = "http",
 274         .init = http_send_init,
 275         .shutdown = http_shutdown,
 276         .pre_select = http_pre_select,
 277         .post_select = http_post_select,
 278         .send = http_send,
 279         .shutdown_clients = http_shutdown_clients,
 280         .client_cmds = {
 281                 [SENDER_on] = http_com_on,
 282                 [SENDER_off] = http_com_off,
 283                 [SENDER_deny] = http_com_deny,
 284                 [SENDER_allow] = http_com_allow,
 285         },
 286         .help = generic_sender_help,
 287         .status = http_status,
 288 };