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 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
  36
  37 struct dccp_fec_client {
  38         struct fec_client_parms fcp;
  39         struct fec_client *fc;
  40 };
  41
  42 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
  43                 __a_unused fd_set *wfds)
  44 {
  45         if (dss->listen_fd >= 0)
  46                 para_fd_set(dss->listen_fd, rfds, max_fileno);
  47 }
  48
  49 /**
  50  * Query the TX CCID used on the sender-client half connection.
  51  * \param sockfd Server socket descriptor to query (after accept(2)).
  52  * \return CCID number > 0, -1 on error/incompatibility.
  53  *
  54  * NB: This feature is only available on Linux > 2.6.30; on older kernels
  55  * ENOPROTOOPT ("Protocol not available") will be returned.
  56  */
  57 static int dccp_get_tx_ccid(int sockfd)
  58 {
  59         int tx_ccid;
  60         socklen_t len = sizeof(tx_ccid);
  61
  62         if (getsockopt(sockfd, SOL_DCCP,
  63                        DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
  64                 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
  65                 return -1;
  66         }
  67         return tx_ccid;
  68 }
  69
  70 static void dccp_shutdown_client(struct sender_client *sc)
  71 {
  72         struct dccp_fec_client *dfc = sc->private_data;
  73
  74         vss_del_fec_client(dfc->fc);
  75         shutdown_client(sc, dss);
  76 }
  77
  78 static void dccp_shutdown_clients(void)
  79 {
  80         struct sender_client *sc, *tmp;
  81
  82         list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
  83                 dccp_shutdown_client(sc);
  84 }
  85
  86 /** * Obtain current MPS according to RFC 4340, sec. 14. */
  87 static int dccp_init_fec(struct sender_client *sc)
  88 {
  89         int mps, ret;
  90         socklen_t ml = sizeof(mps);
  91
  92         /* If call fails, return some sensible minimum value */
  93         ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
  94         if (ret < 0) {
  95                 PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
  96                 mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
  97         }
  98         PARA_INFO_LOG("current MPS = %d bytes\n", mps);
  99         assert(mps > 0);
 100         return mps;
 101 }
 102
 103 static int dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
 104 {
 105         int ret = write_nonblock(sc->fd, buf, len, 0);
 106
 107         if (ret < 0)
 108                 dccp_shutdown_client(sc);
 109         return ret;
 110 }
 111
 112 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 113 {
 114         struct sender_client *sc;
 115         struct dccp_fec_client *dfc;
 116         int tx_ccid;
 117
 118         sc = accept_sender_client(dss, rfds);
 119         if (!sc)
 120                 return;
 121
 122         /* If CCID identifiable, present client as <host>#<port>~<ccid> */
 123         tx_ccid = dccp_get_tx_ccid(sc->fd);
 124         if (tx_ccid != -1) {
 125                 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
 126
 127                 free(sc->name);
 128                 sc->name = tmp;
 129         }
 130         /*
 131          * Bypass unused CCID paths: the sender does not receive application data
 132          * from the client; by shutting down this unused communication path we can
 133          * reduce processing costs a bit. See analogous comment in dccp_recv.c.
 134          */
 135         if (shutdown(sc->fd, SHUT_RD) < 0) {
 136                 PARA_WARNING_LOG("%s\n", strerror(errno));
 137                 shutdown_client(sc, dss);
 138                 return;
 139         }
 140         dfc = para_calloc(sizeof(*dfc));
 141         sc->private_data = dfc;
 142         dfc->fcp.slices_per_group       = 4;
 143         dfc->fcp.data_slices_per_group  = 3;
 144         dfc->fcp.init_fec               = dccp_init_fec;
 145         dfc->fcp.send_fec               = dccp_send_fec;
 146         dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
 147 }
 148
 149 static int dccp_com_on(__a_unused struct sender_command_data *scd)
 150 {
 151         return generic_com_on(dss, IPPROTO_DCCP);
 152 }
 153
 154 static int dccp_com_off(__a_unused struct sender_command_data *scd)
 155 {
 156         generic_com_off(dss);
 157         return 1;
 158 }
 159
 160
 161 static int dccp_com_deny(struct sender_command_data *scd)
 162 {
 163         generic_com_deny(scd, dss);
 164         return 1;
 165 }
 166
 167 static int dccp_com_allow(struct sender_command_data *scd)
 168 {
 169         generic_com_allow(scd, dss);
 170         return 1;
 171 }
 172
 173 /**
 174  * Return list of available CCIDs or warning, in static buffer.
 175  */
 176 static const char *dccp_list_available_ccids(void)
 177 {
 178         /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
 179         static char list[DCCP_MAX_HOST_CCIDS * 4];
 180         uint8_t *ccids;
 181         int i, len, nccids;
 182
 183         nccids = dccp_available_ccids(&ccids);
 184         if (nccids < 0) {
 185                 snprintf(list, sizeof(list), "Unable to query available CCIDs");
 186         } else {
 187                 for (i = len = 0; i < nccids; i++)
 188                         len += snprintf(list + len, sizeof(list) - len,
 189                                         "%s%d", i ? " " : "", ccids[i]);
 190         }
 191         return list;
 192 }
 193
 194 static char *dccp_info(void)
 195 {
 196         char *info = get_sender_info(dss, "dccp");
 197         char *ret  = make_message("%s" "\tsupported ccids: %s\n",
 198                                   info, dccp_list_available_ccids());
 199         free(info);
 200         return ret;
 201 }
 202
 203 /**
 204  * The init function of the dccp sender.
 205  *
 206  * \param s pointer to the dccp sender struct.
 207  *
 208  * It initializes all function pointers of \a s and starts
 209  * listening on the given port.
 210  */
 211 void dccp_send_init(struct sender *s)
 212 {
 213         int ret;
 214
 215         s->info = dccp_info;
 216         s->send = NULL;
 217         s->pre_select = dccp_pre_select;
 218         s->post_select = dccp_post_select;
 219         s->shutdown_clients = dccp_shutdown_clients;
 220         s->help = generic_sender_help;
 221         s->client_cmds[SENDER_ON] = dccp_com_on;
 222         s->client_cmds[SENDER_OFF] = dccp_com_off;
 223         s->client_cmds[SENDER_DENY] = dccp_com_deny;
 224         s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
 225         s->client_cmds[SENDER_ADD] = NULL;
 226         s->client_cmds[SENDER_DELETE] = NULL;
 227
 228         init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
 229                 conf.dccp_port_arg, conf.dccp_max_clients_arg,
 230                 conf.dccp_default_deny_given);
 231         ret = generic_com_on(dss, IPPROTO_DCCP);
 232         if (ret < 0)
 233                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 234 }