dccp_recv.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_recv.c paraslash's dccp receiver */
   8
   9 /*
  10  * based on client.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
  18 #include "para.h"
  19 #include "error.h"
  20 #include "list.h"
  21 #include "sched.h"
  22 #include "ggo.h"
  23 #include "recv.h"
  24 #include "string.h"
  25 #include "net.h"
  26 #include "fd.h"
  27 #include "buffer_tree.h"
  28
  29 #include "dccp_recv.cmdline.h"
  30
  31 /**
  32  * data specific to the dccp receiver
  33  *
  34  * \sa receiver receiver_node
  35  */
  36 struct private_dccp_recv_data {
  37         /** the file descriptor for the dccp socket */
  38         int fd;
  39         struct btr_pool *btrp;
  40 };
  41
  42
  43 static void dccp_recv_close(struct receiver_node *rn)
  44 {
  45
  46         struct private_dccp_recv_data *pdd = rn->private_data;
  47
  48         if (pdd && pdd->fd > 0)
  49                 close(pdd->fd);
  50         btr_pool_free(pdd->btrp);
  51         free(rn->private_data);
  52         rn->private_data = NULL;
  53 }
  54
  55
  56 static int dccp_recv_open(struct receiver_node *rn)
  57 {
  58         struct private_dccp_recv_data *pdd;
  59         struct dccp_recv_args_info *conf = rn->conf;
  60         struct flowopts *fo = NULL;
  61         uint8_t *ccids = NULL;
  62         int fd, ret, i;
  63
  64         /* Copy CCID preference list (u8 array required) */
  65         if (conf->ccid_given) {
  66                 ccids = para_malloc(conf->ccid_given);
  67                 fo    = flowopt_new();
  68
  69                 for (i = 0; i < conf->ccid_given; i++)
  70                         ccids[i] = conf->ccid_arg[i];
  71
  72                 OPT_ADD(fo, SOL_DCCP, DCCP_SOCKOPT_CCID, ccids, i);
  73         }
  74
  75         fd = makesock(IPPROTO_DCCP, 0, conf->host_arg, conf->port_arg, fo);
  76         free(ccids);
  77         if (fd < 0)
  78                 return fd;
  79         /*
  80          * Disable unused CCIDs: the receiver does not send any application
  81          * data to the server. By shutting down this unused path we reduce
  82          * internal processing costs, as the unused CCIDs (in the kernel) are
  83          * then bypassed.
  84          */
  85         if (shutdown(fd, SHUT_WR) < 0) {
  86                 ret = -ERRNO_TO_PARA_ERROR(errno);
  87                 goto err;
  88         }
  89         ret = mark_fd_nonblocking(fd);
  90         if (ret < 0)
  91                 goto err;
  92         rn->private_data = pdd = para_calloc(sizeof(struct private_dccp_recv_data));
  93         pdd->btrp = btr_pool_new("dccp_recv", 320 * 1024);
  94         pdd->fd = fd;
  95         return 1;
  96 err:
  97         close(fd);
  98         return ret;
  99 }
 100
 101 /**
 102  * Check whether the host supports the requested 'ccid' arguments.
 103  * \param conf DCCP receiver arguments.
 104  * \return True if all CCIDs requested in \a conf are supported.
 105  */
 106 static bool dccp_recv_ccid_support_check(struct dccp_recv_args_info *conf)
 107 {
 108         uint8_t *ccids;
 109         int i, j, nccids;
 110
 111         nccids = dccp_available_ccids(&ccids);
 112         if (nccids <= 0)
 113                 return false;
 114
 115         for (i = 0; i < conf->ccid_given; i++) {
 116                 for (j = 0; j < nccids && ccids[j] != conf->ccid_arg[i]; j++)
 117                         ;
 118                 if (j == nccids) {
 119                         PARA_ERROR_LOG("'CCID-%d' not supported on this host.\n",
 120                                         conf->ccid_arg[i]);
 121                         return false;
 122                 }
 123         }
 124         return true;
 125 }
 126
 127 static void *dccp_recv_parse_config(int argc, char **argv)
 128 {
 129         struct dccp_recv_args_info *tmp = para_calloc(sizeof(*tmp));
 130
 131         if (!dccp_recv_cmdline_parser(argc, argv, tmp) &&
 132             dccp_recv_ccid_support_check(tmp))
 133                 return tmp;
 134         free(tmp);
 135         return NULL;
 136 }
 137
 138 static void dccp_recv_pre_select(struct sched *s, struct task *t)
 139 {
 140         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 141         struct private_dccp_recv_data *pdd = rn->private_data;
 142
 143         t->error = 0;
 144         if (generic_recv_pre_select(s, t) <= 0)
 145                 return;
 146         para_fd_set(pdd->fd, &s->rfds, &s->max_fileno);
 147 }
 148
 149 static void dccp_recv_post_select(struct sched *s, struct task *t)
 150 {
 151         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 152         struct private_dccp_recv_data *pdd = rn->private_data;
 153         struct btr_node *btrn = rn->btrn;
 154         struct iovec iov[2];
 155         int ret, iovcnt;
 156         size_t num_bytes;
 157
 158         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 159         if (ret <= 0)
 160                 goto out;
 161         iovcnt = btr_pool_get_buffers(pdd->btrp, iov);
 162         ret = -E_DCCP_OVERRUN;
 163         if (iovcnt == 0)
 164                 goto out;
 165         ret = readv_nonblock(pdd->fd, iov, iovcnt, &s->rfds, &num_bytes);
 166         if (num_bytes == 0)
 167                 goto out;
 168         if (num_bytes <= iov[0].iov_len) /* only the first buffer was filled */
 169                 btr_add_output_pool(pdd->btrp, num_bytes, btrn);
 170         else { /* both buffers contain data */
 171                 btr_add_output_pool(pdd->btrp, iov[0].iov_len, btrn);
 172                 btr_add_output_pool(pdd->btrp, num_bytes - iov[0].iov_len, btrn);
 173         }
 174 out:
 175         if (ret >= 0)
 176                 return;
 177         btr_remove_node(rn->btrn);
 178         t->error = ret;
 179 }
 180
 181 static void dccp_recv_free_config(void *conf)
 182 {
 183         dccp_recv_cmdline_parser_free(conf);
 184         free(conf);
 185 }
 186
 187 /**
 188  * The init function of the dccp receiver.
 189  *
 190  * \param r Pointer to the receiver struct to initialize.
 191  *
 192  * Initialize all function pointers of \a r.
 193  */
 194 void dccp_recv_init(struct receiver *r)
 195 {
 196         struct dccp_recv_args_info dummy;
 197
 198         dccp_recv_cmdline_parser_init(&dummy);
 199         r->open = dccp_recv_open;
 200         r->close = dccp_recv_close;
 201         r->pre_select = dccp_recv_pre_select;
 202         r->post_select = dccp_recv_post_select;
 203         r->parse_config = dccp_recv_parse_config;
 204         r->free_config = dccp_recv_free_config;
 205         r->help = (struct ggo_help) {
 206                 .short_help = dccp_recv_args_info_help,
 207                 .detailed_help = dccp_recv_args_info_detailed_help
 208         };
 209         dccp_recv_cmdline_parser_free(&dummy);
 210 }