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 "string.h"
  20 #include "afh.h"
  21 #include "afs.h"
  22 #include "server.h"
  23 #include "net.h"
  24 #include "list.h"
  25 #include "vss.h"
  26 #include "send.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         /** The socket `name' of the client. */
  45         char *name;
  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         ret = para_accept(listen_fd, NULL, 0);
  71         if (ret < 0) {
  72                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
  73                 return;
  74         }
  75         dc = para_calloc(sizeof(struct dccp_client));
  76         dc->fd = ret;
  77         dc->name = make_message("%s", remote_name(dc->fd));
  78         PARA_NOTICE_LOG("connection from %s\n", dc->name);
  79         para_list_add(&dc->node, &clients);
  80         add_close_on_fork_list(dc->fd);
  81         mark_fd_nonblocking(dc->fd);
  82         dc->cq = cq_new(DCCP_MAX_PENDING_BYTES);
  83 }
  84
  85 static int dccp_open(void)
  86 {
  87         int ret = para_listen(AF_UNSPEC, IPPROTO_DCCP, conf.dccp_port_arg);
  88
  89         if (ret < 0)
  90                 return ret;
  91         listen_fd = ret;
  92         add_close_on_fork_list(listen_fd);
  93         mark_fd_nonblocking(listen_fd);
  94         return 1;
  95 }
  96
  97 static void dccp_shutdown_client(struct dccp_client *dc)
  98 {
  99         PARA_DEBUG_LOG("shutting down %s (fd %d)\n", dc->name, dc->fd);
 100         free(dc->name);
 101         close(dc->fd);
 102         del_close_on_fork_list(dc->fd);
 103         cq_destroy(dc->cq);
 104         list_del(&dc->node);
 105         free(dc);
 106 }
 107
 108 /*
 109  * ret: Negative on errors, zero if nothing was written and write returned
 110  * EAGAIN, number of bytes written else.
 111  */
 112 static int dccp_write(int fd, const char *buf, size_t len)
 113 {
 114         size_t written = 0;
 115         int ret = 0;
 116
 117         while (written < len) {
 118                 ret = write(fd, buf + written, PARA_MIN(1024, len - written));
 119                 /*
 120                  * Error handling: CCID3 has a sending wait queue which fills up and is
 121                  * emptied asynchronously. The EAGAIN case means that there is currently
 122                  * no space in the wait queue, but this can change at any moment and is
 123                  * thus not an error condition.
 124                  */
 125                 if (ret < 0 && errno == EAGAIN)
 126                         return written;
 127                 if (ret < 0) {
 128                         PARA_ERROR_LOG("%s\n", strerror(errno));
 129                         return -E_DCCP_WRITE;
 130                 }
 131                 written += ret;
 132         }
 133         return written;
 134 }
 135
 136 static int queue_chunk_or_shutdown(struct dccp_client *dc, long unsigned chunk_num,
 137         size_t sent)
 138 {
 139         int ret = cq_enqueue(dc->cq, chunk_num, sent);
 140         if (ret < 0) {
 141                 PARA_NOTICE_LOG("enqueue error\n");
 142                 dccp_shutdown_client(dc);
 143         }
 144         return ret;
 145 }
 146
 147 static int send_queued_chunks(struct dccp_client *dc)
 148 {
 149         struct queued_chunk *qc;
 150         while ((qc = cq_peek(dc->cq))) {
 151                 char *buf;
 152                 size_t len;
 153                 int ret;
 154                 cq_get(qc, &buf, &len);
 155                 ret = dccp_write(dc->fd, buf, len);
 156                 if (ret < 0)
 157                         return ret;
 158                 cq_update(dc->cq, ret);
 159                 if (ret != len)
 160                         return 1;
 161                 cq_dequeue(dc->cq);
 162         }
 163         return 1;
 164 }
 165
 166 static void dccp_send(long unsigned current_chunk,
 167                 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
 168 {
 169         struct dccp_client *dc, *tmp;
 170         int ret;
 171         char *header_buf;
 172         size_t header_len;
 173
 174         if (listen_fd < 0 || !len)
 175                 return;
 176
 177         list_for_each_entry_safe(dc, tmp, &clients, node) {
 178                 if (!dc->header_sent && current_chunk) {
 179                         header_buf = vss_get_header(&header_len);
 180                         if (header_buf && header_len > 0) {
 181                                 if (queue_chunk_or_shutdown(dc, -1U, 0) < 0)
 182                                         continue;
 183                         }
 184                         dc->header_sent = 1;
 185                 }
 186                 ret = send_queued_chunks(dc);
 187                 if (ret < 0) {
 188                         dccp_shutdown_client(dc);
 189                         continue;
 190                 }
 191 //              PARA_DEBUG_LOG("writing %d bytes to fd %d\n", len, dc->fd);
 192                 ret = dccp_write(dc->fd, buf, len);
 193                 if (ret < 0) {
 194                         PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
 195                         dccp_shutdown_client(dc);
 196                         continue;
 197                 }
 198                 if (ret != len)
 199                         queue_chunk_or_shutdown(dc, current_chunk, ret);
 200         }
 201 }
 202
 203 static void dccp_shutdown_clients(void)
 204 {
 205         struct dccp_client *dc, *tmp;
 206
 207         list_for_each_entry_safe(dc, tmp, &clients, node)
 208                 dccp_shutdown_client(dc);
 209 }
 210
 211 static char *dccp_info(void)
 212 {
 213         static char *buf;
 214         int num_clients = 0;
 215         struct dccp_client *dc, *tmp;
 216
 217         free(buf);
 218         list_for_each_entry_safe(dc, tmp, &clients, node)
 219                 num_clients++;
 220         buf = make_message("dccp connected clients: %d\n", num_clients);
 221         return buf;
 222 }
 223
 224 static char *dccp_help(void)
 225 {
 226         return make_message("no help available\n");
 227 }
 228
 229 /**
 230  * the init function of the dccp sender
 231  *
 232  * \param s pointer to the dccp sender struct
 233  *
 234  * It initializes all function pointers of \a s and starts
 235  * listening on the given port.
 236  */
 237 void dccp_send_init(struct sender *s)
 238 {
 239         int ret;
 240
 241         INIT_LIST_HEAD(&clients);
 242         s->info = dccp_info;
 243         s->send = dccp_send;
 244         s->pre_select = dccp_pre_select;
 245         s->post_select = dccp_post_select;
 246         s->shutdown_clients = dccp_shutdown_clients;
 247         s->help = dccp_help;
 248         s->client_cmds[SENDER_ON] = NULL;
 249         s->client_cmds[SENDER_OFF] = NULL;
 250         s->client_cmds[SENDER_DENY] = NULL;
 251         s->client_cmds[SENDER_ALLOW] = NULL;
 252         s->client_cmds[SENDER_ADD] = NULL;
 253         s->client_cmds[SENDER_DELETE] = NULL;
 254         self = s;
 255         ret = dccp_open();
 256         if (ret < 0) {
 257                 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 258                 s->status = SENDER_OFF;
 259         } else
 260                 s->status = SENDER_ON;
 261 }