dccp_recv.c

   1 /*
   2  * Copyright (C) 2006-2007 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 ret = makesock(AF_UNSPEC, IPPROTO_DCCP, 0, conf->host_arg, conf->port_arg);
  61
  62         if (ret < 0)
  63                 return ret;
  64         /*
  65          * Disable unused CCIDs: the receiver does not send any application data to the
  66          * server. By shutting down this unused path we reduce internal processing costs,
  67          * as the unused CCIDs (in the kernel) are then bypassed.
  68          */
  69         if (shutdown(ret, SHUT_WR) < 0)
  70                 return -ERRNO_TO_PARA_ERROR(errno);
  71
  72         rn->buf = para_calloc(DCCP_BUFSIZE);
  73         rn->private_data = pdd = para_calloc(sizeof(struct private_dccp_recv_data));
  74
  75         pdd->fd = ret;
  76         mark_fd_nonblocking(pdd->fd);
  77         return 1;
  78 }
  79
  80 static void dccp_shutdown(void)
  81 {
  82         ; /* nothing to do */
  83 }
  84
  85 static void *dccp_recv_parse_config(int argc, char **argv)
  86 {
  87         struct dccp_recv_args_info *tmp = para_calloc(sizeof(struct dccp_recv_args_info));
  88
  89         if (!dccp_recv_cmdline_parser(argc, argv, tmp))
  90                 return tmp;
  91         free(tmp);
  92         return NULL;
  93 }
  94
  95 static void dccp_recv_pre_select(struct sched *s, struct task *t)
  96 {
  97         struct receiver_node *rn = t->private_data;
  98         struct private_dccp_recv_data *pdd = rn->private_data;
  99
 100         t->ret = 1;
 101         para_fd_set(pdd->fd, &s->rfds, &s->max_fileno);
 102 }
 103
 104 static void dccp_recv_post_select(struct sched *s, struct task *t)
 105 {
 106         struct receiver_node *rn = t->private_data;
 107         struct private_dccp_recv_data *pdd = rn->private_data;
 108
 109         if (rn->output_error && *rn->output_error) {
 110                 t->ret = *rn->output_error;
 111                 goto out;
 112         }
 113         t->ret = 1;
 114         if (!s->select_ret || !FD_ISSET(pdd->fd, &s->rfds))
 115                 goto out; /* nothing to do */
 116         t->ret = -E_DCCP_OVERRUN;
 117         if (rn->loaded >= DCCP_BUFSIZE)
 118                 goto out;
 119         t->ret = recv_bin_buffer(pdd->fd, rn->buf + rn->loaded,
 120                 DCCP_BUFSIZE - rn->loaded);
 121         if (t->ret <= 0) {
 122                 if (!t->ret)
 123                         t->ret = -E_RECV_EOF;
 124                 goto out;
 125         }
 126         rn->loaded += t->ret;
 127         return;
 128 out:
 129         if (t->ret < 0)
 130                 rn->error = t->ret;
 131 }
 132
 133 /**
 134  * the init function of the dccp receiver
 135  *
 136  * \param r pointer to the receiver struct to initialize
 137  *
 138  * Initialize all function pointers of \a r
 139  */
 140 void dccp_recv_init(struct receiver *r)
 141 {
 142         r->shutdown = dccp_shutdown;
 143         r->open = dccp_recv_open;
 144         r->close = dccp_recv_close;
 145         r->pre_select = dccp_recv_pre_select;
 146         r->post_select = dccp_recv_post_select;
 147         r->parse_config = dccp_recv_parse_config;
 148 }