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         free_sender_status(hss);
  84 }
  85
  86 static int queue_chunk_or_shutdown(struct sender_client *sc,
  87                 struct sender_status *ss, const char *buf, size_t num_bytes)
  88 {
  89         int ret = cq_enqueue(sc->cq, buf, num_bytes);
  90         if (ret < 0)
  91                 shutdown_client(sc, ss);
  92         return ret;
  93 }
  94
  95 /**
  96  * Send one chunk of audio data to a connected client.
  97  *
  98  * \param sc The client.
  99  * \param ss The sender.
 100  * \param current_chunk The number of the chunk to write.
 101  * \param buf The data to write.
 102  * \param len The number of bytes of \a buf.
 103  * \param header_buf The audio file header.
 104  * \param header_len The number of bytes of \a header_buf.
 105  *
 106  * On errors, the client is shut down. If only a part of the buffer could be
 107  * written, the remainder is put into the chunk queue for that client.
 108  */
 109 static void http_send_chunk(struct sender_client *sc, struct sender_status *ss,
 110                 long unsigned current_chunk, const char *buf, size_t len,
 111                 const char *header_buf, size_t header_len)
 112 {
 113         int ret;
 114
 115         if (!sc->header_sent && current_chunk) {
 116                 if (header_buf && header_len > 0) {
 117                         ret = queue_chunk_or_shutdown(sc, ss, header_buf, header_len);
 118                         if (ret < 0)
 119                                 goto out;
 120                 }
 121         }
 122         sc->header_sent = 1;
 123         ret = send_queued_chunks(sc->fd, sc->cq);
 124         if (ret < 0) {
 125                 shutdown_client(sc, ss);
 126                 goto out;
 127         }
 128         if (!len)
 129                 goto out;
 130         if (!ret) { /* still data left in the queue */
 131                 ret = queue_chunk_or_shutdown(sc, ss, buf, len);
 132                 goto out;
 133         }
 134         ret = xwrite(sc->fd, buf, len);
 135         if (ret < 0) {
 136                 shutdown_client(sc, ss);
 137                 goto out;
 138         }
 139         if (ret != len)
 140                 ret = queue_chunk_or_shutdown(sc, ss, buf + ret, len - ret);
 141 out:
 142         if (ret < 0)
 143                 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
 144 }
 145
 146 static void http_send(long unsigned current_chunk,
 147         __a_unused long unsigned chunks_sent, const char *buf, size_t len,
 148         const char *header_buf, size_t header_len)
 149 {
 150         struct sender_client *sc, *tmp;
 151
 152         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 153                 struct private_http_sender_data *phsd = sc->private_data;
 154
 155                 if (phsd->status == HTTP_STREAMING)
 156                         http_send_chunk(sc, hss, current_chunk, buf, len,
 157                                    header_buf, header_len);
 158         }
 159 }
 160
 161 static void http_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 162 {
 163         struct sender_client *sc, *tmp;
 164         struct private_http_sender_data *phsd;
 165         int ret;
 166
 167         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 168                 phsd = sc->private_data;
 169                 switch (phsd->status) {
 170                 case HTTP_STREAMING: /* nothing to do */
 171                         break;
 172                 case HTTP_CONNECTED: /* need to recv get request */
 173                         ret = read_pattern(sc->fd, HTTP_GET_MSG, MAXLINE, rfds);
 174                         if (ret < 0)
 175                                 phsd->status = HTTP_INVALID_GET_REQUEST;
 176                         else if (ret > 0) {
 177                                 phsd->status = HTTP_GOT_GET_REQUEST;
 178                                 PARA_INFO_LOG("received get request\n");
 179                         }
 180                         break;
 181                 case HTTP_GOT_GET_REQUEST: /* need to send ok msg */
 182                         phsd->status = HTTP_STREAMING;
 183                         http_send_ok_msg(sc);
 184                         break;
 185                 case HTTP_INVALID_GET_REQUEST: /* need to send err msg */
 186                         if (http_send_err_msg(sc) >= 0)
 187                                 shutdown_client(sc, hss);
 188                         break;
 189                 }
 190         }
 191         sc = accept_sender_client(hss, rfds);
 192         if (!sc)
 193                 return;
 194         phsd = para_malloc(sizeof(*phsd));
 195         sc->private_data = phsd;
 196         phsd->status = HTTP_CONNECTED;
 197 }
 198
 199 static void http_pre_select(int *max_fileno, fd_set *rfds, fd_set *wfds)
 200 {
 201         struct sender_client *sc, *tmp;
 202         unsigned n;
 203
 204         FOR_EACH_LISTEN_FD(n, hss) {
 205                 if (hss->listen_fds[n] < 0)
 206                         continue;
 207                 para_fd_set(hss->listen_fds[n], rfds, max_fileno);
 208         }
 209         list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
 210                 struct private_http_sender_data *phsd = sc->private_data;
 211                 if (phsd->status == HTTP_CONNECTED) /* need to recv get request */
 212                         para_fd_set(sc->fd, rfds, max_fileno);
 213                 if (phsd->status == HTTP_GOT_GET_REQUEST ||
 214                                 phsd->status == HTTP_INVALID_GET_REQUEST)
 215                         para_fd_set(sc->fd, wfds, max_fileno);
 216         }
 217 }
 218
 219 static int http_com_on(__a_unused struct sender_command_data *scd)
 220 {
 221         generic_com_on(hss, IPPROTO_TCP);
 222         return 1;
 223 }
 224
 225 static int http_com_off(__a_unused struct sender_command_data *scd)
 226 {
 227         generic_com_off(hss);
 228         return 1;
 229 }
 230
 231 static int http_com_deny(struct sender_command_data *scd)
 232 {
 233         generic_com_deny(scd, hss);
 234         return 1;
 235 }
 236
 237 static int http_com_allow(struct sender_command_data *scd)
 238 {
 239         generic_com_allow(scd, hss);
 240         return 1;
 241 }
 242
 243 static char *http_status(void)
 244 {
 245         return generic_sender_status(hss, "http");
 246 }
 247
 248 /*
 249  * Initialize the client list and the access control list, and optionally
 250  * listen on the tcp port.
 251  */
 252 static void http_send_init(void)
 253 {
 254         init_sender_status(hss, OPT_RESULT(HTTP_ACCESS),
 255                 OPT_RESULT(HTTP_LISTEN_ADDRESS),
 256                 OPT_UINT32_VAL(HTTP_PORT), OPT_UINT32_VAL(HTTP_MAX_CLIENTS),
 257                 OPT_GIVEN(HTTP_DEFAULT_DENY));
 258         if (OPT_GIVEN(HTTP_NO_AUTOSTART))
 259                 return;
 260         generic_com_on(hss, IPPROTO_TCP);
 261 }
 262
 263 /**
 264  * The HTTP sender.
 265  *
 266  * This is the only sender which does not FEC-encode the stream. This is not
 267  * necessary because HTTP sits on top of TCP, a reliable transport which
 268  * retransmits lost packets automatically. The sender employs per-client queues
 269  * which queue chunks of audio data if they can not be sent immediately because
 270  * the write operation would block. Most methods of the sender are implemented
 271  * as wrappers for the generic functions defined in \ref send_common.c.
 272  */
 273 const struct sender http_sender = {
 274         .name = "http",
 275         .init = http_send_init,
 276         .shutdown = http_shutdown,
 277         .pre_select = http_pre_select,
 278         .post_select = http_post_select,
 279         .send = http_send,
 280         .shutdown_clients = http_shutdown_clients,
 281         .client_cmds = {
 282                 [SENDER_on] = http_com_on,
 283                 [SENDER_off] = http_com_off,
 284                 [SENDER_deny] = http_com_deny,
 285                 [SENDER_allow] = http_com_allow,
 286         },
 287         .help = generic_sender_help,
 288         .status = http_status,
 289 };