dccp_recv.c

   1 /* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file dccp_recv.c paraslash's dccp receiver */
   4
   5 /*
   6  * based on client.c of dccp-cs-0.01.tar.bz2,
   7  * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
   8  */
   9
  10 #include <netinet/in.h>
  11 #include <sys/socket.h>
  12 #include <regex.h>
  13 #include <sys/types.h>
  14 #include <arpa/inet.h>
  15 #include <sys/un.h>
  16 #include <netdb.h>
  17 #include <lopsub.h>
  18
  19 #include "recv_cmd.lsg.h"
  20 #include "para.h"
  21 #include "error.h"
  22 #include "list.h"
  23 #include "sched.h"
  24 #include "buffer_tree.h"
  25 #include "recv.h"
  26 #include "string.h"
  27 #include "net.h"
  28 #include "fd.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 /* Check whether the host supports the requested 'ccid' arguments. */
  38 static int dccp_recv_ccid_support_check(const struct lls_parse_result *lpr)
  39 {
  40         uint8_t *ccids;
  41         int i, j, ret, nccids;
  42         unsigned given = RECV_CMD_OPT_GIVEN(DCCP, CCID, lpr);
  43
  44         ret = dccp_available_ccids(&ccids);
  45         if (ret < 0)
  46                 return ret;
  47         nccids = ret;
  48         for (i = 0; i < given; i++) {
  49                 uint32_t val = lls_uint32_val(i,
  50                         RECV_CMD_OPT_RESULT(DCCP, CCID, lpr));
  51                 for (j = 0; j < nccids && ccids[j] != val; j++)
  52                         ;
  53                 if (j == nccids) {
  54                         PARA_ERROR_LOG("'CCID-%u' not supported on this host\n",
  55                                 val);
  56                         return -ERRNO_TO_PARA_ERROR(EINVAL);
  57                 }
  58         }
  59         return 1;
  60 }
  61
  62 static int dccp_recv_open(struct receiver_node *rn)
  63 {
  64         struct lls_parse_result *lpr = rn->lpr;
  65         struct flowopts *fo = NULL;
  66         uint8_t *ccids = NULL;
  67         int fd, ret, i;
  68         const struct lls_opt_result *r_c = RECV_CMD_OPT_RESULT(DCCP, CCID, lpr);
  69         const char *host = RECV_CMD_OPT_STRING_VAL(DCCP, HOST, lpr);
  70         uint32_t port = RECV_CMD_OPT_UINT32_VAL(DCCP, PORT, lpr);
  71         unsigned given;
  72
  73         ret = dccp_recv_ccid_support_check(lpr);
  74         if (ret < 0)
  75                 return ret;
  76         /* Copy CCID preference list (u8 array required) */
  77         given = lls_opt_given(r_c);
  78         if (given) {
  79                 ccids = para_malloc(given);
  80                 fo = flowopt_new();
  81                 for (i = 0; i < given; i++)
  82                         ccids[i] = lls_int32_val(i, r_c);
  83                 OPT_ADD(fo, SOL_DCCP, DCCP_SOCKOPT_CCID, ccids, i);
  84         }
  85
  86         fd = makesock(IPPROTO_DCCP, 0, host, port, fo);
  87         flowopt_cleanup(fo);
  88         free(ccids);
  89         if (fd < 0)
  90                 return fd;
  91         /*
  92          * Disable unused CCIDs: the receiver does not send any application
  93          * data to the server. By shutting down this unused path we reduce
  94          * internal processing costs, as the unused CCIDs (in the kernel) are
  95          * then bypassed.
  96          */
  97         if (shutdown(fd, SHUT_WR) < 0) {
  98                 ret = -ERRNO_TO_PARA_ERROR(errno);
  99                 goto err;
 100         }
 101         ret = mark_fd_nonblocking(fd);
 102         if (ret < 0)
 103                 goto err;
 104         rn->btrp = btr_pool_new("dccp_recv", 320 * 1024);
 105         rn->fd = fd;
 106         return 1;
 107 err:
 108         close(fd);
 109         return ret;
 110 }
 111
 112 static void dccp_recv_pre_select(struct sched *s, void *context)
 113 {
 114         struct receiver_node *rn = context;
 115
 116         if (generic_recv_pre_select(s, rn) <= 0)
 117                 return;
 118         para_fd_set(rn->fd, &s->rfds, &s->max_fileno);
 119 }
 120
 121 static int dccp_recv_post_select(struct sched *s, void *context)
 122 {
 123         struct receiver_node *rn = context;
 124         struct btr_node *btrn = rn->btrn;
 125         struct iovec iov[2];
 126         int ret, iovcnt;
 127         size_t num_bytes;
 128
 129         ret = task_get_notification(rn->task);
 130         if (ret < 0)
 131                 goto out;
 132         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 133         if (ret <= 0)
 134                 goto out;
 135         iovcnt = btr_pool_get_buffers(rn->btrp, iov);
 136         ret = -E_DCCP_OVERRUN;
 137         if (iovcnt == 0)
 138                 goto out;
 139         ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
 140         if (num_bytes == 0)
 141                 goto out;
 142         if (num_bytes <= iov[0].iov_len) /* only the first buffer was filled */
 143                 btr_add_output_pool(rn->btrp, num_bytes, btrn);
 144         else { /* both buffers contain data */
 145                 btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
 146                 btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len, btrn);
 147         }
 148 out:
 149         if (ret < 0)
 150                 btr_remove_node(&rn->btrn);
 151         return ret;
 152 }
 153
 154 const struct receiver lsg_recv_cmd_com_dccp_user_data = {
 155         .open = dccp_recv_open,
 156         .close = dccp_recv_close,
 157         .pre_select = dccp_recv_pre_select,
 158         .post_select = dccp_recv_post_select,
 159 };