dccp_send.c

   1 /*
   2  * Copyright (C) 2006-2010 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 <regex.h>
  15 #include <sys/types.h>
  16 #include <dirent.h>
  17 #include <osl.h>
  18
  19 #include "para.h"
  20 #include "error.h"
  21 #include "string.h"
  22 #include "afh.h"
  23 #include "afs.h"
  24 #include "server.h"
  25 #include "net.h"
  26 #include "list.h"
  27 #include "vss.h"
  28 #include "send.h"
  29 #include "fd.h"
  30 #include "close_on_fork.h"
  31 #include "chunk_queue.h"
  32 #include "server.cmdline.h"
  33 #include "acl.h"
  34
  35 /** Do not write more than that many bytes at once. */
  36 #define DCCP_MAX_BYTES_PER_WRITE 1024
  37
  38 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
  39
  40 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
  41                 __a_unused fd_set *wfds)
  42 {
  43         if (dss->listen_fd >= 0)
  44                 para_fd_set(dss->listen_fd, rfds, max_fileno);
  45 }
  46
  47 /**
  48  * Query the TX CCID used on the sender-client half connection.
  49  * \param sockfd Server socket descriptor to query (after accept(2)).
  50  * \return CCID number > 0, -1 on error/incompatibility.
  51  *
  52  * NB: This feature is only available on Linux > 2.6.30; on older kernels
  53  * ENOPROTOOPT ("Protocol not available") will be returned.
  54  */
  55 static int dccp_get_tx_ccid(int sockfd)
  56 {
  57         int tx_ccid;
  58         socklen_t len = sizeof(tx_ccid);
  59
  60         if (getsockopt(sockfd, SOL_DCCP,
  61                        DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
  62                 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
  63                 return -1;
  64         }
  65         return tx_ccid;
  66 }
  67
  68 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  69 {
  70         struct sender_client *sc;
  71         int tx_ccid;
  72
  73         sc = accept_sender_client(dss, rfds);
  74         if (!sc)
  75                 return;
  76
  77         /* If CCID identifiable, present client as <host>#<port>~<ccid> */
  78         tx_ccid = dccp_get_tx_ccid(sc->fd);
  79         if (tx_ccid != -1) {
  80                 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
  81
  82                 free(sc->name);
  83                 sc->name = tmp;
  84         }
  85         /*
  86          * Bypass unused CCID paths: the sender does not receive application data
  87          * from the client; by shutting down this unused communication path we can
  88          * reduce processing costs a bit. See analogous comment in dccp_recv.c.
  89          */
  90         if (shutdown(sc->fd, SHUT_RD) >= 0)
  91                 return;
  92         PARA_WARNING_LOG("%s\n", strerror(errno));
  93         shutdown_client(sc, dss);
  94 }
  95
  96 static void dccp_send(long unsigned current_chunk,
  97                 __a_unused long unsigned chunks_sent, const char *buf,
  98                 size_t len, const char *header_buf, size_t header_len)
  99 {
 100         struct sender_client *sc, *tmp;
 101
 102         list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
 103                 send_chunk(sc, dss, DCCP_MAX_BYTES_PER_WRITE, current_chunk, buf,
 104                         len, header_buf, header_len);
 105 }
 106
 107 static void dccp_shutdown_clients(void)
 108 {
 109         shutdown_clients(dss);
 110 }
 111
 112 static int dccp_com_on(__a_unused struct sender_command_data *scd)
 113 {
 114         return generic_com_on(dss, IPPROTO_DCCP);
 115 }
 116
 117 static int dccp_com_off(__a_unused struct sender_command_data *scd)
 118 {
 119         generic_com_off(dss);
 120         return 1;
 121 }
 122
 123
 124 static int dccp_com_deny(struct sender_command_data *scd)
 125 {
 126         generic_com_deny(scd, dss);
 127         return 1;
 128 }
 129
 130 static int dccp_com_allow(struct sender_command_data *scd)
 131 {
 132         generic_com_allow(scd, dss);
 133         return 1;
 134 }
 135
 136 /**
 137  * Return list of available CCIDs or warning, in static buffer.
 138  */
 139 static const char *dccp_list_available_ccids(void)
 140 {
 141         /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
 142         static char list[DCCP_MAX_HOST_CCIDS * 4];
 143         uint8_t *ccids;
 144         int i, len, nccids;
 145
 146         nccids = dccp_available_ccids(&ccids);
 147         if (nccids < 0) {
 148                 snprintf(list, sizeof(list), "Unable to query available CCIDs");
 149         } else {
 150                 for (i = len = 0; i < nccids; i++)
 151                         len += snprintf(list + len, sizeof(list) - len,
 152                                         "%s%d", i ? " " : "", ccids[i]);
 153         }
 154         return list;
 155 }
 156
 157 static char *dccp_info(void)
 158 {
 159         char *info = get_sender_info(dss, "dccp");
 160         char *ret  = make_message("%s" "\tsupported ccids: %s\n",
 161                                   info, dccp_list_available_ccids());
 162         free(info);
 163         return ret;
 164 }
 165
 166 /**
 167  * The init function of the dccp sender.
 168  *
 169  * \param s pointer to the dccp sender struct.
 170  *
 171  * It initializes all function pointers of \a s and starts
 172  * listening on the given port.
 173  */
 174 void dccp_send_init(struct sender *s)
 175 {
 176         int ret;
 177
 178         s->info = dccp_info;
 179         s->send = dccp_send;
 180         s->pre_select = dccp_pre_select;
 181         s->post_select = dccp_post_select;
 182         s->shutdown_clients = dccp_shutdown_clients;
 183         s->help = generic_sender_help;
 184         s->client_cmds[SENDER_ON] = dccp_com_on;
 185         s->client_cmds[SENDER_OFF] = dccp_com_off;
 186         s->client_cmds[SENDER_DENY] = dccp_com_deny;
 187         s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
 188         s->client_cmds[SENDER_ADD] = NULL;
 189         s->client_cmds[SENDER_DELETE] = NULL;
 190
 191         init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
 192                 conf.dccp_port_arg, conf.dccp_max_clients_arg,
 193                 conf.dccp_default_deny_given);
 194         ret = generic_com_on(dss, IPPROTO_DCCP);
 195         if (ret < 0)
 196                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 197 }