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