dccp_recv.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_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 <sys/types.h>
  15 #include <dirent.h>
  16
  17 #include "para.h"
  18 #include "error.h"
  19 #include "list.h"
  20 #include "sched.h"
  21 #include "recv.h"
  22 #include "string.h"
  23 #include "net.h"
  24 #include "fd.h"
  25
  26 #include "dccp_recv.cmdline.h"
  27
  28 /** the size of the output buffer */
  29 #define DCCP_BUFSIZE 40960
  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 };
  40
  41
  42 static void dccp_recv_close(struct receiver_node *rn)
  43 {
  44
  45         struct private_dccp_recv_data *pdd = rn->private_data;
  46
  47         if (pdd && pdd->fd > 0)
  48                 close(pdd->fd);
  49         free(rn->buf);
  50         rn->buf = NULL;
  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         int fd, ret = makesock(AF_UNSPEC, IPPROTO_DCCP, 0, conf->host_arg,
  61                 conf->port_arg);
  62
  63         if (ret < 0)
  64                 return ret;
  65         fd = ret;
  66         /*
  67          * Disable unused CCIDs: the receiver does not send any application
  68          * data to the server. By shutting down this unused path we reduce
  69          * internal processing costs, as the unused CCIDs (in the kernel) are
  70          * then bypassed.
  71          */
  72         if (shutdown(fd, SHUT_WR) < 0) {
  73                 ret = -ERRNO_TO_PARA_ERROR(errno);
  74                 goto err;
  75         }
  76         ret = mark_fd_nonblocking(fd);
  77         if (ret < 0)
  78                 goto err;
  79         rn->buf = para_calloc(DCCP_BUFSIZE);
  80         rn->private_data = pdd = para_calloc(sizeof(struct private_dccp_recv_data));
  81         pdd->fd = fd;
  82         return 1;
  83 err:
  84         close(fd);
  85         return ret;
  86 }
  87
  88 static void dccp_shutdown(void)
  89 {
  90         ; /* nothing to do */
  91 }
  92
  93 static void *dccp_recv_parse_config(int argc, char **argv)
  94 {
  95         struct dccp_recv_args_info *tmp = para_calloc(sizeof(struct dccp_recv_args_info));
  96
  97         if (!dccp_recv_cmdline_parser(argc, argv, tmp))
  98                 return tmp;
  99         free(tmp);
 100         return NULL;
 101 }
 102
 103 static void dccp_recv_pre_select(struct sched *s, struct task *t)
 104 {
 105         struct receiver_node *rn = t->private_data;
 106         struct private_dccp_recv_data *pdd = rn->private_data;
 107
 108         t->ret = 1;
 109         para_fd_set(pdd->fd, &s->rfds, &s->max_fileno);
 110 }
 111
 112 static void dccp_recv_post_select(struct sched *s, struct task *t)
 113 {
 114         struct receiver_node *rn = t->private_data;
 115         struct private_dccp_recv_data *pdd = rn->private_data;
 116
 117         if (rn->output_error && *rn->output_error) {
 118                 t->ret = *rn->output_error;
 119                 goto out;
 120         }
 121         t->ret = 1;
 122         if (!s->select_ret || !FD_ISSET(pdd->fd, &s->rfds))
 123                 goto out; /* nothing to do */
 124         t->ret = -E_DCCP_OVERRUN;
 125         if (rn->loaded >= DCCP_BUFSIZE)
 126                 goto out;
 127         t->ret = recv_bin_buffer(pdd->fd, rn->buf + rn->loaded,
 128                 DCCP_BUFSIZE - rn->loaded);
 129         if (t->ret <= 0) {
 130                 if (!t->ret)
 131                         t->ret = -E_RECV_EOF;
 132                 goto out;
 133         }
 134         rn->loaded += t->ret;
 135         return;
 136 out:
 137         if (t->ret < 0)
 138                 rn->error = t->ret;
 139 }
 140
 141 /**
 142  * the init function of the dccp receiver
 143  *
 144  * \param r pointer to the receiver struct to initialize
 145  *
 146  * Initialize all function pointers of \a r
 147  */
 148 void dccp_recv_init(struct receiver *r)
 149 {
 150         r->shutdown = dccp_shutdown;
 151         r->open = dccp_recv_open;
 152         r->close = dccp_recv_close;
 153         r->pre_select = dccp_recv_pre_select;
 154         r->post_select = dccp_recv_post_select;
 155         r->parse_config = dccp_recv_parse_config;
 156 }