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 "server.h"
  15 #include "net.h"
  16 #include "list.h"
  17 #include "vss.h"
  18 #include "send.h"
  19 #include "dccp.h"
  20 #include "error.h"
  21 #include "string.h"
  22 #include "fd.h"
  23 #include "close_on_fork.h"
  24 #include "server.cmdline.h"
  25
  26 /** the list of connected clients **/
  27 static struct list_head clients;
  28 static int listen_fd = -1;
  29 static struct sender *self;
  30
  31 /** describes one connected client */
  32 struct dccp_client {
  33         /** the dccp socket */
  34         int fd;
  35         /** address information about the client */
  36         struct sockaddr_in addr;
  37         /** the position of this client in the client list */
  38         struct list_head node;
  39         /** non-zero if audio file header has been sent */
  40         int header_sent;
  41 };
  42
  43 static void dccp_pre_select( int *max_fileno, fd_set *rfds,
  44                 __a_unused fd_set *wfds)
  45 {
  46         if (listen_fd < 0)
  47                 return;
  48         FD_SET(listen_fd, rfds);
  49         *max_fileno = PARA_MAX(*max_fileno, listen_fd);
  50 }
  51
  52 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  53 {
  54         struct dccp_client *dc;
  55         int ret;
  56
  57         if (!FD_ISSET(listen_fd, rfds))
  58                 return;
  59         dc = para_calloc(sizeof(struct dccp_client));
  60         ret = para_accept(listen_fd, &dc->addr, sizeof(struct sockaddr_in));
  61         if (ret < 0) {
  62                 PARA_ERROR_LOG("%s", PARA_STRERROR(-ret));
  63                 return;
  64         }
  65         PARA_NOTICE_LOG("connection from %s\n", inet_ntoa(dc->addr.sin_addr));
  66         dc->fd = ret;
  67         para_list_add(&dc->node, &clients);
  68         add_close_on_fork_list(dc->fd);
  69         mark_fd_nonblock(dc->fd);
  70 }
  71
  72 static int dccp_open(void)
  73 {
  74         struct sockaddr_in servaddr;
  75         int ret;
  76
  77         ret = dccp_get_socket();
  78         if (ret < 0)
  79                 return ret;
  80         listen_fd = ret;
  81
  82         memset(&servaddr, 0, sizeof(servaddr));
  83         servaddr.sin_family = AF_INET;
  84         servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  85         servaddr.sin_port = htons(conf.dccp_port_arg);
  86         ret = bind(listen_fd, (struct sockaddr *)&servaddr, sizeof(servaddr));
  87         if (ret < 0)
  88                 return -E_DCCP_BIND;
  89         ret = dccp_set_socket(listen_fd);
  90         if (ret < 0)
  91                 return ret;
  92         ret = listen(listen_fd, 0);
  93         if (ret < 0)
  94                 return -E_DCCP_LISTEN;
  95         PARA_DEBUG_LOG("listening on fd %d\n", listen_fd);
  96         add_close_on_fork_list(listen_fd);
  97         mark_fd_nonblock(listen_fd);
  98         return 1;
  99 }
 100
 101 static void dccp_shutdown_client(struct dccp_client *dc)
 102 {
 103         PARA_DEBUG_LOG("shutting down %s (fd %d)\n", inet_ntoa(dc->addr.sin_addr),
 104                 dc->fd);
 105         close(dc->fd);
 106         del_close_on_fork_list(dc->fd);
 107         list_del(&dc->node);
 108         free(dc);
 109 }
 110
 111 /** give up if write would block that many times */
 112 #define DCCP_WRITE_RETRIES 100
 113
 114 static int dccp_write(int fd, const char *buf, size_t len)
 115 {
 116         size_t size, written = 0;
 117         int ret, retries = 0;
 118 again:
 119         size = PARA_MIN(1024, len - written);
 120         ret = write(fd, buf + written, size);
 121         if (ret < 0) {
 122                 if (errno != EAGAIN || retries++ > DCCP_WRITE_RETRIES)
 123                         goto err_out;
 124                 PARA_DEBUG_LOG("EAGAIN #%d@%zd/%zd\n", retries, written, len);
 125                 goto again;
 126         }
 127         retries = 0;
 128         written += ret;
 129         if (written >= len)
 130                 return written;
 131         ret = write_ok(fd);
 132         if (ret > 0)
 133                 goto again;
 134 err_out:
 135         return -E_DCCP_WRITE;
 136 }
 137
 138 static void dccp_send(long unsigned current_chunk,
 139                 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
 140 {
 141         struct dccp_client *dc, *tmp;
 142         int ret;
 143         char *header_buf;
 144         unsigned header_len;
 145
 146         if (listen_fd < 0 || !len)
 147                 return;
 148
 149         list_for_each_entry_safe(dc, tmp, &clients, node) {
 150                 ret = write_ok(dc->fd);
 151                 if (ret < 0) {
 152                         dccp_shutdown_client(dc);
 153                         continue;
 154                 }
 155                 if (!ret)
 156                         continue;
 157                 if (!dc->header_sent && current_chunk) {
 158                         header_buf = vss_get_header(&header_len);
 159                         if (header_buf && header_len > 0) {
 160                                 ret = dccp_write(dc->fd, header_buf, header_len);
 161                                 if (ret != header_len) {
 162                                         int err = errno;
 163                                         PARA_ERROR_LOG("header write: %d/%u (%s)\n",
 164                                                 ret, header_len, ret < 0?
 165                                                 strerror(err) : "");
 166                                         dccp_shutdown_client(dc);
 167                                         continue;
 168                                 }
 169                                 dc->header_sent = 1;
 170                                 ret = write_ok(dc->fd);
 171                                 if (ret < 0) {
 172                                         dccp_shutdown_client(dc);
 173                                         continue;
 174                                 }
 175                                 if (!ret)
 176                                         continue;
 177                         }
 178                 }
 179 //              PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
 180                 ret = dccp_write(dc->fd, buf, len);
 181                 if (ret != len)
 182                         dccp_shutdown_client(dc);
 183         }
 184 }
 185
 186 static void dccp_shutdown_clients(void)
 187 {
 188         struct dccp_client *dc, *tmp;
 189
 190         list_for_each_entry_safe(dc, tmp, &clients, node)
 191                 dccp_shutdown_client(dc);
 192 }
 193
 194 static char *dccp_info(void)
 195 {
 196         static char *buf;
 197         int num_clients = 0;
 198         struct dccp_client *dc, *tmp;
 199
 200         free(buf);
 201         list_for_each_entry_safe(dc, tmp, &clients, node)
 202                 num_clients++;
 203         buf = make_message("dccp connected clients: %d\n", num_clients);
 204         return buf;
 205 }
 206
 207 static char *dccp_help(void)
 208 {
 209         return make_message("no help available\n");
 210 }
 211
 212 /**
 213  * the init function of the dccp sender
 214  *
 215  * \param s pointer to the dccp sender struct
 216  *
 217  * It initializes all function pointers of \a s and starts
 218  * listening on the given port.
 219  */
 220 void dccp_send_init(struct sender *s)
 221 {
 222         int ret;
 223
 224         INIT_LIST_HEAD(&clients);
 225         s->info = dccp_info;
 226         s->send = dccp_send;
 227         s->pre_select = dccp_pre_select;
 228         s->post_select = dccp_post_select;
 229         s->shutdown_clients = dccp_shutdown_clients;
 230         s->help = dccp_help;
 231         s->client_cmds[SENDER_ON] = NULL;
 232         s->client_cmds[SENDER_OFF] = NULL;
 233         s->client_cmds[SENDER_DENY] = NULL;
 234         s->client_cmds[SENDER_ALLOW] = NULL;
 235         s->client_cmds[SENDER_ADD] = NULL;
 236         s->client_cmds[SENDER_DELETE] = NULL;
 237         self = s;
 238         ret = dccp_open();
 239         if (ret < 0) {
 240                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 241                 s->status = SENDER_OFF;
 242         } else
 243                 s->status = SENDER_ON;
 244 }