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