dccp_send.c

   1 /*
   2  * Copyright (C) 2006-2008 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 #include "acl.h"
  32
  33 /** the list of connected clients **/
  34 static struct list_head clients;
  35 /** The whitelist/blacklist. */
  36 static struct list_head dccp_acl;
  37 static int listen_fd = -1;
  38
  39 /** Maximal number of bytes in a chunk queue. */
  40 #define DCCP_MAX_PENDING_BYTES 40000
  41
  42 /** Do not write more than that many bytes at once. */
  43 #define DCCP_MAX_BYTES_PER_WRITE 1024
  44
  45 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
  46                 __a_unused fd_set *wfds)
  47 {
  48         if (listen_fd >= 0)
  49                 para_fd_set(listen_fd, rfds, max_fileno);
  50 }
  51
  52 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
  53 {
  54         struct sender_client *sc;
  55         int ret, fd;
  56
  57         if (listen_fd < 0 || !FD_ISSET(listen_fd, rfds))
  58                 return;
  59         ret = para_accept(listen_fd, NULL, 0);
  60         if (ret < 0) {
  61                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
  62                 return;
  63         }
  64         fd = ret;
  65         /*
  66          * Bypass unused CCID paths: the sender does not receive application data
  67          * from the client; by shutting down this unused communication path we can
  68          * reduce processing costs a bit. See analogous comment in dccp_recv.c.
  69          */
  70         if (shutdown(fd, SHUT_RD) < 0) {
  71                 ret = -ERRNO_TO_PARA_ERROR(errno);
  72                 goto err;
  73         }
  74         ret = mark_fd_nonblocking(fd);
  75         if (ret < 0)
  76                 goto err;
  77         ret = acl_check_access(fd, &dccp_acl, conf.dccp_default_deny_given);
  78         if (ret < 0)
  79                 goto err;
  80         sc = para_calloc(sizeof(*sc));
  81         sc->fd = fd;
  82         sc->name = make_message("%s", remote_name(sc->fd));
  83         PARA_NOTICE_LOG("connection from %s\n", sc->name);
  84         para_list_add(&sc->node, &clients);
  85         add_close_on_fork_list(sc->fd);
  86         sc->cq = cq_new(DCCP_MAX_PENDING_BYTES);
  87         return;
  88 err:
  89         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
  90         close(fd);
  91 }
  92
  93 static void dccp_send(long unsigned current_chunk,
  94                 __a_unused long unsigned chunks_sent, const char *buf, size_t len)
  95 {
  96         struct sender_client *sc, *tmp;
  97
  98         list_for_each_entry_safe(sc, tmp, &clients, node)
  99                 send_chunk(sc, DCCP_MAX_BYTES_PER_WRITE, current_chunk, buf,
 100                         len);
 101 }
 102
 103 static void dccp_shutdown_clients(void)
 104 {
 105         struct sender_client *sc, *tmp;
 106
 107         list_for_each_entry_safe(sc, tmp, &clients, node)
 108                 shutdown_client(sc);
 109 }
 110
 111 static int dccp_com_deny(struct sender_command_data *scd)
 112 {
 113         acl_deny(scd->addr, scd->netmask, &dccp_acl,
 114                 conf.dccp_default_deny_given);
 115         return 1;
 116 }
 117
 118 static int dccp_com_allow(struct sender_command_data *scd)
 119 {
 120         acl_allow(scd->addr, scd->netmask, &dccp_acl,
 121                 conf.dccp_default_deny_given);
 122         return 1;
 123 }
 124
 125 static char *dccp_info(void)
 126 {
 127         int num_clients = 0;
 128         struct sender_client *sc, *tmp;
 129
 130         list_for_each_entry_safe(sc, tmp, &clients, node)
 131                 num_clients++;
 132         return make_message("dccp connected clients: %d\n", num_clients);
 133 }
 134
 135 static char *dccp_help(void)
 136 {
 137         return make_message("no help available\n");
 138 }
 139
 140 /**
 141  * The init function of the dccp sender.
 142  *
 143  * \param s pointer to the dccp sender struct.
 144  *
 145  * It initializes all function pointers of \a s and starts
 146  * listening on the given port.
 147  */
 148 void dccp_send_init(struct sender *s)
 149 {
 150         int ret;
 151
 152         INIT_LIST_HEAD(&clients);
 153         s->info = dccp_info;
 154         s->send = dccp_send;
 155         s->pre_select = dccp_pre_select;
 156         s->post_select = dccp_post_select;
 157         s->shutdown_clients = dccp_shutdown_clients;
 158         s->help = dccp_help;
 159         s->client_cmds[SENDER_ON] = NULL;
 160         s->client_cmds[SENDER_OFF] = NULL;
 161         s->client_cmds[SENDER_DENY] = dccp_com_deny;
 162         s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
 163         s->client_cmds[SENDER_ADD] = NULL;
 164         s->client_cmds[SENDER_DELETE] = NULL;
 165         acl_init(&dccp_acl, conf.dccp_access_arg, conf.dccp_access_given);
 166         ret = open_sender(IPPROTO_DCCP, conf.dccp_port_arg);
 167         if (ret < 0)
 168                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 169         else
 170                 listen_fd = ret;
 171 }