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 "send.h"
  28 #include "vss.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 struct dccp_fec_client {
  41         struct fec_client_parms fcp;
  42         struct fec_client *fc;
  43 };
  44
  45 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
  46                 __a_unused fd_set *wfds)
  47 {
  48         if (dss->listen_fd >= 0)
  49                 para_fd_set(dss->listen_fd, rfds, max_fileno);
  50 }
  51
  52 /**
  53  * Query the TX CCID used on the sender-client half connection.
  54  * \param sockfd Server socket descriptor to query (after accept(2)).
  55  * \return CCID number > 0, -1 on error/incompatibility.
  56  *
  57  * NB: This feature is only available on Linux > 2.6.30; on older kernels
  58  * ENOPROTOOPT ("Protocol not available") will be returned.
  59  */
  60 static int dccp_get_tx_ccid(int sockfd)
  61 {
  62         int tx_ccid;
  63         socklen_t len = sizeof(tx_ccid);
  64
  65         if (getsockopt(sockfd, SOL_DCCP,
  66                        DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
  67                 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
  68                 return -1;
  69         }
  70         return tx_ccid;
  71 }
  72
  73 static void dccp_shutdown_client(struct sender_client *sc)
  74 {
  75         struct dccp_fec_client *dfc = sc->private_data;
  76
  77         vss_del_fec_client(dfc->fc);
  78         shutdown_client(sc, dss);
  79 }
  80
  81 static void dccp_shutdown_clients(void)
  82 {
  83         struct sender_client *sc, *tmp;
  84
  85         list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
  86                 dccp_shutdown_client(sc);
  87 }
  88
  89 static int dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
  90 {
  91         int ret = write_nonblock(sc->fd, buf, len, DCCP_MAX_BYTES_PER_WRITE);
  92
  93         if (ret < 0)
  94                 dccp_shutdown_client(sc);
  95         return ret;
  96 }
  97
  98 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  99 {
 100         struct sender_client *sc;
 101         struct dccp_fec_client *dfc;
 102         int tx_ccid;
 103
 104         sc = accept_sender_client(dss, rfds);
 105         if (!sc)
 106                 return;
 107
 108         /* If CCID identifiable, present client as <host>#<port>~<ccid> */
 109         tx_ccid = dccp_get_tx_ccid(sc->fd);
 110         if (tx_ccid != -1) {
 111                 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
 112
 113                 free(sc->name);
 114                 sc->name = tmp;
 115         }
 116         /*
 117          * Bypass unused CCID paths: the sender does not receive application data
 118          * from the client; by shutting down this unused communication path we can
 119          * reduce processing costs a bit. See analogous comment in dccp_recv.c.
 120          */
 121         if (shutdown(sc->fd, SHUT_RD) < 0) {
 122                 PARA_WARNING_LOG("%s\n", strerror(errno));
 123                 shutdown_client(sc, dss);
 124                 return;
 125         }
 126         dfc = para_calloc(sizeof(*dfc));
 127         sc->private_data = dfc;
 128         dfc->fcp.slices_per_group       = 4;
 129         dfc->fcp.data_slices_per_group  = 3;
 130         dfc->fcp.max_slice_bytes        = DCCP_MAX_BYTES_PER_WRITE; /* FIXME */
 131         dfc->fcp.init_fec               = NULL; /* FIXME */
 132         dfc->fcp.send_fec               = dccp_send_fec;
 133         dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
 134 }
 135
 136 static int dccp_com_on(__a_unused struct sender_command_data *scd)
 137 {
 138         return generic_com_on(dss, IPPROTO_DCCP);
 139 }
 140
 141 static int dccp_com_off(__a_unused struct sender_command_data *scd)
 142 {
 143         generic_com_off(dss);
 144         return 1;
 145 }
 146
 147
 148 static int dccp_com_deny(struct sender_command_data *scd)
 149 {
 150         generic_com_deny(scd, dss);
 151         return 1;
 152 }
 153
 154 static int dccp_com_allow(struct sender_command_data *scd)
 155 {
 156         generic_com_allow(scd, dss);
 157         return 1;
 158 }
 159
 160 /**
 161  * Return list of available CCIDs or warning, in static buffer.
 162  */
 163 static const char *dccp_list_available_ccids(void)
 164 {
 165         /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
 166         static char list[DCCP_MAX_HOST_CCIDS * 4];
 167         uint8_t *ccids;
 168         int i, len, nccids;
 169
 170         nccids = dccp_available_ccids(&ccids);
 171         if (nccids < 0) {
 172                 snprintf(list, sizeof(list), "Unable to query available CCIDs");
 173         } else {
 174                 for (i = len = 0; i < nccids; i++)
 175                         len += snprintf(list + len, sizeof(list) - len,
 176                                         "%s%d", i ? " " : "", ccids[i]);
 177         }
 178         return list;
 179 }
 180
 181 static char *dccp_info(void)
 182 {
 183         char *info = get_sender_info(dss, "dccp");
 184         char *ret  = make_message("%s" "\tsupported ccids: %s\n",
 185                                   info, dccp_list_available_ccids());
 186         free(info);
 187         return ret;
 188 }
 189
 190 /**
 191  * The init function of the dccp sender.
 192  *
 193  * \param s pointer to the dccp sender struct.
 194  *
 195  * It initializes all function pointers of \a s and starts
 196  * listening on the given port.
 197  */
 198 void dccp_send_init(struct sender *s)
 199 {
 200         int ret;
 201
 202         s->info = dccp_info;
 203         s->send = NULL;
 204         s->pre_select = dccp_pre_select;
 205         s->post_select = dccp_post_select;
 206         s->shutdown_clients = dccp_shutdown_clients;
 207         s->help = generic_sender_help;
 208         s->client_cmds[SENDER_ON] = dccp_com_on;
 209         s->client_cmds[SENDER_OFF] = dccp_com_off;
 210         s->client_cmds[SENDER_DENY] = dccp_com_deny;
 211         s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
 212         s->client_cmds[SENDER_ADD] = NULL;
 213         s->client_cmds[SENDER_DELETE] = NULL;
 214
 215         init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
 216                 conf.dccp_port_arg, conf.dccp_max_clients_arg,
 217                 conf.dccp_default_deny_given);
 218         ret = generic_com_on(dss, IPPROTO_DCCP);
 219         if (ret < 0)
 220                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 221 }