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 static struct sender *self;
  40
  41
  42 struct dccp_fec_client {
  43         struct fec_client_parms fcp;
  44         struct fec_client *fc;
  45         struct sender_client *sc;
  46 };
  47
  48 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
  49                 __a_unused fd_set *wfds)
  50 {
  51         if (dss->listen_fd >= 0)
  52                 para_fd_set(dss->listen_fd, rfds, max_fileno);
  53 }
  54
  55 /**
  56  * Query the TX CCID used on the sender-client half connection.
  57  * \param sockfd Server socket descriptor to query (after accept(2)).
  58  * \return CCID number > 0, -1 on error/incompatibility.
  59  *
  60  * NB: This feature is only available on Linux > 2.6.30; on older kernels
  61  * ENOPROTOOPT ("Protocol not available") will be returned.
  62  */
  63 static int dccp_get_tx_ccid(int sockfd)
  64 {
  65         int tx_ccid;
  66         socklen_t len = sizeof(tx_ccid);
  67
  68         if (getsockopt(sockfd, SOL_DCCP,
  69                        DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
  70                 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
  71                 return -1;
  72         }
  73         return tx_ccid;
  74 }
  75
  76 static void dccp_shutdown_client(struct sender_client *sc)
  77 {
  78         struct dccp_fec_client *dfc = sc->private_data;
  79
  80         vss_del_fec_client(dfc->fc);
  81         shutdown_client(sc, dss);
  82 }
  83
  84 static void dccp_shutdown_clients(void)
  85 {
  86         struct sender_client *sc, *tmp;
  87
  88         list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
  89                 dccp_shutdown_client(sc);
  90 }
  91
  92 static int dccp_open(void *client, struct fec_client_parms **fcp)
  93 {
  94         struct dccp_fec_client *dfc = client;
  95
  96         dfc->fcp.slices_per_group = 4;
  97         dfc->fcp.data_slices_per_group = 3;
  98         dfc->fcp.max_slice_bytes = 1472;
  99         *fcp = &dfc->fcp;
 100         return 1;
 101 }
 102
 103 static int dccp_send_fec(char *buf, size_t len, void *private_data)
 104 {
 105         struct dccp_fec_client *dfc = private_data;
 106         int ret = write_nonblock(dfc->sc->fd, buf, len, DCCP_MAX_BYTES_PER_WRITE);
 107
 108         if (ret < 0)
 109                 dccp_shutdown_client(dfc->sc);
 110         return ret;
 111 }
 112
 113 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 114 {
 115         struct sender_client *sc;
 116         struct dccp_fec_client *dfc;
 117         int tx_ccid;
 118
 119         sc = accept_sender_client(dss, rfds);
 120         if (!sc)
 121                 return;
 122
 123         /* If CCID identifiable, present client as <host>#<port>~<ccid> */
 124         tx_ccid = dccp_get_tx_ccid(sc->fd);
 125         if (tx_ccid != -1) {
 126                 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
 127
 128                 free(sc->name);
 129                 sc->name = tmp;
 130         }
 131         /*
 132          * Bypass unused CCID paths: the sender does not receive application data
 133          * from the client; by shutting down this unused communication path we can
 134          * reduce processing costs a bit. See analogous comment in dccp_recv.c.
 135          */
 136         if (shutdown(sc->fd, SHUT_RD) < 0) {
 137                 PARA_WARNING_LOG("%s\n", strerror(errno));
 138                 shutdown_client(sc, dss);
 139                 return;
 140         }
 141         dfc = para_calloc(sizeof(*dfc));
 142         sc->private_data = dfc;
 143         dfc->sc = sc;
 144         /* XXX RESOLVED LATER vss_add_fec_client(self, dfc, &dfc->fc); */
 145 }
 146
 147 static int dccp_com_on(__a_unused struct sender_command_data *scd)
 148 {
 149         return generic_com_on(dss, IPPROTO_DCCP);
 150 }
 151
 152 static int dccp_com_off(__a_unused struct sender_command_data *scd)
 153 {
 154         generic_com_off(dss);
 155         return 1;
 156 }
 157
 158
 159 static int dccp_com_deny(struct sender_command_data *scd)
 160 {
 161         generic_com_deny(scd, dss);
 162         return 1;
 163 }
 164
 165 static int dccp_com_allow(struct sender_command_data *scd)
 166 {
 167         generic_com_allow(scd, dss);
 168         return 1;
 169 }
 170
 171 /**
 172  * Return list of available CCIDs or warning, in static buffer.
 173  */
 174 static const char *dccp_list_available_ccids(void)
 175 {
 176         /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
 177         static char list[DCCP_MAX_HOST_CCIDS * 4];
 178         uint8_t *ccids;
 179         int i, len, nccids;
 180
 181         nccids = dccp_available_ccids(&ccids);
 182         if (nccids < 0) {
 183                 snprintf(list, sizeof(list), "Unable to query available CCIDs");
 184         } else {
 185                 for (i = len = 0; i < nccids; i++)
 186                         len += snprintf(list + len, sizeof(list) - len,
 187                                         "%s%d", i ? " " : "", ccids[i]);
 188         }
 189         return list;
 190 }
 191
 192 static char *dccp_info(void)
 193 {
 194         char *info = get_sender_info(dss, "dccp");
 195         char *ret  = make_message("%s" "\tsupported ccids: %s\n",
 196                                   info, dccp_list_available_ccids());
 197         free(info);
 198         return ret;
 199 }
 200
 201 /**
 202  * The init function of the dccp sender.
 203  *
 204  * \param s pointer to the dccp sender struct.
 205  *
 206  * It initializes all function pointers of \a s and starts
 207  * listening on the given port.
 208  */
 209 void dccp_send_init(struct sender *s)
 210 {
 211         int ret;
 212
 213         s->info = dccp_info;
 214         s->send = NULL;
 215         s->open = dccp_open;
 216         s->send_fec = dccp_send_fec;
 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         self = s;
 235 }