dccp_recv.c

   1 /*
   2  * Copyright (C) 2006-2011 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
  17 #include "para.h"
  18 #include "error.h"
  19 #include "list.h"
  20 #include "sched.h"
  21 #include "ggo.h"
  22 #include "recv.h"
  23 #include "string.h"
  24 #include "net.h"
  25 #include "fd.h"
  26 #include "buffer_tree.h"
  27
  28 #include "dccp_recv.cmdline.h"
  29
  30 /**
  31  * data specific to the dccp receiver
  32  *
  33  * \sa receiver receiver_node
  34  */
  35 struct private_dccp_recv_data {
  36         /** the file descriptor for the dccp socket */
  37         int fd;
  38         struct btr_pool *btrp;
  39 };
  40
  41 static void dccp_recv_close(struct receiver_node *rn)
  42 {
  43
  44         struct private_dccp_recv_data *pdd = rn->private_data;
  45
  46         if (pdd && pdd->fd > 0)
  47                 close(pdd->fd);
  48         btr_pool_free(pdd->btrp);
  49         free(rn->private_data);
  50         rn->private_data = NULL;
  51 }
  52
  53 static int dccp_recv_open(struct receiver_node *rn)
  54 {
  55         struct private_dccp_recv_data *pdd;
  56         struct dccp_recv_args_info *conf = rn->conf;
  57         struct flowopts *fo = NULL;
  58         uint8_t *ccids = NULL;
  59         int fd, ret, i;
  60
  61         /* Copy CCID preference list (u8 array required) */
  62         if (conf->ccid_given) {
  63                 ccids = para_malloc(conf->ccid_given);
  64                 fo    = flowopt_new();
  65
  66                 for (i = 0; i < conf->ccid_given; i++)
  67                         ccids[i] = conf->ccid_arg[i];
  68
  69                 OPT_ADD(fo, SOL_DCCP, DCCP_SOCKOPT_CCID, ccids, i);
  70         }
  71
  72         fd = makesock(IPPROTO_DCCP, 0, conf->host_arg, conf->port_arg, fo);
  73         free(ccids);
  74         if (fd < 0)
  75                 return fd;
  76         /*
  77          * Disable unused CCIDs: the receiver does not send any application
  78          * data to the server. By shutting down this unused path we reduce
  79          * internal processing costs, as the unused CCIDs (in the kernel) are
  80          * then bypassed.
  81          */
  82         if (shutdown(fd, SHUT_WR) < 0) {
  83                 ret = -ERRNO_TO_PARA_ERROR(errno);
  84                 goto err;
  85         }
  86         ret = mark_fd_nonblocking(fd);
  87         if (ret < 0)
  88                 goto err;
  89         rn->private_data = pdd = para_calloc(sizeof(struct private_dccp_recv_data));
  90         pdd->btrp = btr_pool_new("dccp_recv", 320 * 1024);
  91         pdd->fd = fd;
  92         return 1;
  93 err:
  94         close(fd);
  95         return ret;
  96 }
  97
  98 /**
  99  * Check whether the host supports the requested 'ccid' arguments.
 100  * \param conf DCCP receiver arguments.
 101  * \return True if all CCIDs requested in \a conf are supported.
 102  */
 103 static bool dccp_recv_ccid_support_check(struct dccp_recv_args_info *conf)
 104 {
 105         uint8_t *ccids;
 106         int i, j, nccids;
 107
 108         nccids = dccp_available_ccids(&ccids);
 109         if (nccids <= 0)
 110                 return false;
 111
 112         for (i = 0; i < conf->ccid_given; i++) {
 113                 for (j = 0; j < nccids && ccids[j] != conf->ccid_arg[i]; j++)
 114                         ;
 115                 if (j == nccids) {
 116                         PARA_ERROR_LOG("'CCID-%d' not supported on this host.\n",
 117                                         conf->ccid_arg[i]);
 118                         return false;
 119                 }
 120         }
 121         return true;
 122 }
 123
 124 static void *dccp_recv_parse_config(int argc, char **argv)
 125 {
 126         struct dccp_recv_args_info *tmp = para_calloc(sizeof(*tmp));
 127
 128         if (!dccp_recv_cmdline_parser(argc, argv, tmp) &&
 129             dccp_recv_ccid_support_check(tmp))
 130                 return tmp;
 131         free(tmp);
 132         return NULL;
 133 }
 134
 135 static void dccp_recv_pre_select(struct sched *s, struct task *t)
 136 {
 137         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 138         struct private_dccp_recv_data *pdd = rn->private_data;
 139
 140         t->error = 0;
 141         if (generic_recv_pre_select(s, t) <= 0)
 142                 return;
 143         para_fd_set(pdd->fd, &s->rfds, &s->max_fileno);
 144 }
 145
 146 static void dccp_recv_post_select(struct sched *s, struct task *t)
 147 {
 148         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 149         struct private_dccp_recv_data *pdd = rn->private_data;
 150         struct btr_node *btrn = rn->btrn;
 151         struct iovec iov[2];
 152         int ret, iovcnt;
 153         size_t num_bytes;
 154
 155         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 156         if (ret <= 0)
 157                 goto out;
 158         iovcnt = btr_pool_get_buffers(pdd->btrp, iov);
 159         ret = -E_DCCP_OVERRUN;
 160         if (iovcnt == 0)
 161                 goto out;
 162         ret = readv_nonblock(pdd->fd, iov, iovcnt, &s->rfds, &num_bytes);
 163         if (num_bytes == 0)
 164                 goto out;
 165         if (num_bytes <= iov[0].iov_len) /* only the first buffer was filled */
 166                 btr_add_output_pool(pdd->btrp, num_bytes, btrn);
 167         else { /* both buffers contain data */
 168                 btr_add_output_pool(pdd->btrp, iov[0].iov_len, btrn);
 169                 btr_add_output_pool(pdd->btrp, num_bytes - iov[0].iov_len, btrn);
 170         }
 171 out:
 172         if (ret >= 0)
 173                 return;
 174         btr_remove_node(rn->btrn);
 175         t->error = ret;
 176 }
 177
 178 static void dccp_recv_free_config(void *conf)
 179 {
 180         dccp_recv_cmdline_parser_free(conf);
 181         free(conf);
 182 }
 183
 184 /**
 185  * The init function of the dccp receiver.
 186  *
 187  * \param r Pointer to the receiver struct to initialize.
 188  *
 189  * Initialize all function pointers of \a r.
 190  */
 191 void dccp_recv_init(struct receiver *r)
 192 {
 193         struct dccp_recv_args_info dummy;
 194
 195         dccp_recv_cmdline_parser_init(&dummy);
 196         r->open = dccp_recv_open;
 197         r->close = dccp_recv_close;
 198         r->pre_select = dccp_recv_pre_select;
 199         r->post_select = dccp_recv_post_select;
 200         r->parse_config = dccp_recv_parse_config;
 201         r->free_config = dccp_recv_free_config;
 202         r->help = (struct ggo_help) {
 203                 .short_help = dccp_recv_args_info_help,
 204                 .detailed_help = dccp_recv_args_info_detailed_help
 205         };
 206         dccp_recv_cmdline_parser_free(&dummy);
 207 }