dccp_send.c

   1 /*
   2  * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file dccp_send.c paraslash's dccp sender */
   8
   9 /*
  10  * based on server.c of dccp-cs-0.01.tar.bz2,
  11  * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
  12  */
  13
  14 #include <sys/types.h>
  15 #include <dirent.h>
  16
  17 #include "para.h"
  18 #include "error.h"
  19 #include "afh.h"
  20 #include "server.h"
  21 #include "net.h"
  22 #include "list.h"
  23 #include "vss.h"
  24 #include "send.h"
  25 #include "dccp.h"
  26 #include "string.h"
  27 #include "fd.h"
  28 #include "close_on_fork.h"
  29 #include "chunk_queue.h"
  30 #include "server.cmdline.h"
  31
  32 /** the list of connected clients **/
  33 static struct list_head clients;
  34 static int listen_fd = -1;
  35 static struct sender *self;
  36
  37 /** Maximal number of bytes in a chunk queue. */
  38 #define DCCP_MAX_PENDING_BYTES 40000
  39
  40 /** describes one connected client */
  41 struct dccp_client {
  42         /** the dccp socket */
  43         int fd;
  44         /** address information about the client */
  45         struct sockaddr_in addr;
  46         /** the position of this client in the client list */
  47         struct list_head node;
  48         /** non-zero if audio file header has been sent */
  49         int header_sent;
  50         /** The list of pending chunks for this client. */
  51         struct chunk_queue *cq;
  52 };
  53
  54 static void dccp_pre_select( int *max_fileno, fd_set *rfds,
  55                 __a_unused fd_set *wfds)
  56 {
  57         if (listen_fd < 0)
  58                 return;
  59         FD_SET(listen_fd, rfds);
  60         *max_fileno = PARA_MAX(*max_fileno, listen_fd);
  61 }
  62
  63 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  64 {
  65         struct dccp_client *dc;
  66         int ret;
  67
  68         if (!FD_ISSET(listen_fd, rfds))
  69                 return;
  70         dc = para_calloc(sizeof(struct dccp_client));
  71         ret = para_accept(listen_fd, &dc->addr, sizeof(struct sockaddr_in));
  72         if (ret < 0) {
  73                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
  74                 return;
  75         }
  76         PARA_NOTICE_LOG("connection from %s\n", inet_ntoa(dc->addr.sin_addr));
  77         dc->fd = ret;
  78         para_list_add(&dc->node, &clients);
  79         add_close_on_fork_list(dc->fd);
  80         mark_fd_nonblock(dc->fd);
  81         dc->cq = cq_new(DCCP_MAX_PENDING_BYTES);
  82 }
  83
  84 static int dccp_open(void)
  85 {
  86         struct sockaddr_in servaddr;
  87         int ret;
  88
  89         ret = dccp_get_socket();
  90         if (ret < 0)
  91                 return ret;
  92         listen_fd = ret;
  93
  94         memset(&servaddr, 0, sizeof(servaddr));
  95         servaddr.sin_family = AF_INET;
  96         servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  97         servaddr.sin_port = htons(conf.dccp_port_arg);
  98         ret = bind(listen_fd, (struct sockaddr *)&servaddr, sizeof(servaddr));
  99         if (ret < 0)
 100                 return -E_DCCP_BIND;
 101         ret = dccp_set_socket(listen_fd);
 102         if (ret < 0)
 103                 return ret;
 104         ret = listen(listen_fd, 0);
 105         if (ret < 0) {
 106                 PARA_ERROR_LOG("%s\n", strerror(errno));
 107                 return -E_DCCP_LISTEN;
 108         }
 109         PARA_DEBUG_LOG("listening on fd %d\n", listen_fd);
 110         add_close_on_fork_list(listen_fd);
 111         mark_fd_nonblock(listen_fd);
 112         return 1;
 113 }
 114
 115 static void dccp_shutdown_client(struct dccp_client *dc)
 116 {
 117         PARA_DEBUG_LOG("shutting down %s (fd %d)\n", inet_ntoa(dc->addr.sin_addr),
 118                 dc->fd);
 119         close(dc->fd);
 120         del_close_on_fork_list(dc->fd);
 121         cq_destroy(dc->cq);
 122         list_del(&dc->node);
 123         free(dc);
 124 }
 125
 126 /*
 127  * ret: Negative on errors, zero if nothing was written and write returned
 128  * EAGAIN, number of bytes written else.
 129  */
 130 static int dccp_write(int fd, const char *buf, size_t len)
 131 {
 132         size_t written = 0;
 133         int ret = 0;
 134
 135         while (written < len) {
 136                 ret = write(fd, buf + written, PARA_MIN(1024, len - written));
 137                 /*
 138                  * Error handling: CCID3 has a sending wait queue which fills up and is
 139                  * emptied asynchronously. The EAGAIN case means that there is currently
 140                  * no space in the wait queue, but this can change at any moment and is
 141                  * thus not an error condition.
 142                  */
 143                 if (ret < 0 && errno == EAGAIN)
 144                         return written;
 145                 if (ret < 0) {
 146                         PARA_ERROR_LOG("%s\n", strerror(errno));
 147                         return -E_DCCP_WRITE;
 148                 }
 149                 written += ret;
 150         }
 151         return written;
 152 }
 153
 154 static int queue_chunk_or_shutdown(struct dccp_client *dc, long unsigned chunk_num,
 155         size_t sent)
 156 {
 157         int ret = cq_enqueue(dc->cq, chunk_num, sent);
 158         if (ret < 0) {
 159                 PARA_NOTICE_LOG("enqueue error\n");
 160                 dccp_shutdown_client(dc);
 161         }
 162         return ret;
 163 }
 164
 165 static int send_queued_chunks(struct dccp_client *dc)
 166 {
 167         struct queued_chunk *qc;
 168         while ((qc = cq_peek(dc->cq))) {
 169                 char *buf;
 170                 size_t len;
 171                 int ret;
 172                 cq_get(qc, &buf, &len);
 173                 ret = dccp_write(dc->fd, buf, len);
 174                 if (ret < 0)
 175                         return ret;
 176                 cq_update(dc->cq, ret);
 177                 if (ret != len)
 178                         return 1;
 179                 cq_dequeue(dc->cq);
 180         }
 181         return 1;
 182 }
 183
 184 static void dccp_send(long unsigned current_chunk,
 185                 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
 186 {
 187         struct dccp_client *dc, *tmp;
 188         int ret;
 189         char *header_buf;
 190         size_t header_len;
 191
 192         if (listen_fd < 0 || !len)
 193                 return;
 194
 195         list_for_each_entry_safe(dc, tmp, &clients, node) {
 196                 if (!dc->header_sent && current_chunk) {
 197                         header_buf = vss_get_header(&header_len);
 198                         if (header_buf && header_len > 0) {
 199                                 if (queue_chunk_or_shutdown(dc, -1U, 0) < 0)
 200                                         continue;
 201                         }
 202                         dc->header_sent = 1;
 203                 }
 204                 ret = send_queued_chunks(dc);
 205                 if (ret < 0) {
 206                         dccp_shutdown_client(dc);
 207                         continue;
 208                 }
 209 //              PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
 210                 ret = dccp_write(dc->fd, buf, len);
 211                 if (ret < 0) {
 212                         PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
 213                         dccp_shutdown_client(dc);
 214                         continue;
 215                 }
 216                 if (ret != len)
 217                         queue_chunk_or_shutdown(dc, current_chunk, ret);
 218         }
 219 }
 220
 221 static void dccp_shutdown_clients(void)
 222 {
 223         struct dccp_client *dc, *tmp;
 224
 225         list_for_each_entry_safe(dc, tmp, &clients, node)
 226                 dccp_shutdown_client(dc);
 227 }
 228
 229 static char *dccp_info(void)
 230 {
 231         static char *buf;
 232         int num_clients = 0;
 233         struct dccp_client *dc, *tmp;
 234
 235         free(buf);
 236         list_for_each_entry_safe(dc, tmp, &clients, node)
 237                 num_clients++;
 238         buf = make_message("dccp connected clients: %d\n", num_clients);
 239         return buf;
 240 }
 241
 242 static char *dccp_help(void)
 243 {
 244         return make_message("no help available\n");
 245 }
 246
 247 /**
 248  * the init function of the dccp sender
 249  *
 250  * \param s pointer to the dccp sender struct
 251  *
 252  * It initializes all function pointers of \a s and starts
 253  * listening on the given port.
 254  */
 255 void dccp_send_init(struct sender *s)
 256 {
 257         int ret;
 258
 259         INIT_LIST_HEAD(&clients);
 260         s->info = dccp_info;
 261         s->send = dccp_send;
 262         s->pre_select = dccp_pre_select;
 263         s->post_select = dccp_post_select;
 264         s->shutdown_clients = dccp_shutdown_clients;
 265         s->help = dccp_help;
 266         s->client_cmds[SENDER_ON] = NULL;
 267         s->client_cmds[SENDER_OFF] = NULL;
 268         s->client_cmds[SENDER_DENY] = NULL;
 269         s->client_cmds[SENDER_ALLOW] = NULL;
 270         s->client_cmds[SENDER_ADD] = NULL;
 271         s->client_cmds[SENDER_DELETE] = NULL;
 272         self = s;
 273         ret = dccp_open();
 274         if (ret < 0) {
 275                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 276                 s->status = SENDER_OFF;
 277         } else
 278                 s->status = SENDER_ON;
 279 }