lib/ip/sendto.c

   1 #undef NDEBUG
   2
   3 #include <assert.h>
   4 #include <errno.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/socket.h>
  11 #include <netinet/in.h>
  12
  13 #include <net/gen/in.h>
  14 #include <net/gen/udp.h>
  15 #include <net/gen/udp_hdr.h>
  16 #include <net/gen/udp_io.h>
  17
  18 #define DEBUG 0
  19
  20 static ssize_t _udp_sendto(int socket, const void *message, size_t length,
  21         int flags, const struct sockaddr *dest_addr, socklen_t dest_len,
  22         nwio_udpopt_t *udpoptp);
  23
  24 ssize_t sendto(int socket, const void *message, size_t length, int flags,
  25         const struct sockaddr *dest_addr, socklen_t dest_len)
  26 {
  27         int r;
  28         nwio_udpopt_t udpopt;
  29
  30         r= ioctl(socket, NWIOGUDPOPT, &udpopt);
  31         if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
  32         {
  33                 if (r == -1)
  34                         return r;
  35                 return _udp_sendto(socket, message, length, flags,
  36                         dest_addr, dest_len, &udpopt);
  37         }
  38
  39 #if DEBUG
  40         fprintf(stderr, "sendto: not implemented for fd %d\n", socket);
  41 #endif
  42         errno= ENOSYS;
  43         return -1;
  44 }
  45
  46 static ssize_t _udp_sendto(int socket, const void *message, size_t length,
  47         int flags, const struct sockaddr *dest_addr, socklen_t dest_len,
  48         nwio_udpopt_t *udpoptp)
  49 {
  50         int r, t_errno;
  51         size_t buflen;
  52         void *buf;
  53         struct sockaddr_in *sinp;
  54         udp_io_hdr_t *io_hdrp;
  55
  56         if (flags)
  57         {
  58 #if DEBUG
  59                 fprintf(stderr, "sendto(udp): flags not implemented\n");
  60 #endif
  61                 errno= ENOSYS;
  62                 return -1;
  63         }
  64
  65         if (udpoptp->nwuo_flags & NWUO_RWDATONLY)
  66                 return write(socket, message, length);
  67
  68         if ((udpoptp->nwuo_flags & NWUO_RP_ANY) ||
  69                 (udpoptp->nwuo_flags & NWUO_RA_ANY))
  70         {
  71                 if (!dest_addr)
  72                 {
  73                         errno= ENOTCONN;
  74                         return -1;
  75                 }
  76
  77                 /* Check destination address */
  78                 if (dest_len < sizeof(*sinp))
  79                 {
  80                         errno= EINVAL;
  81                         return -1;
  82                 }
  83                 sinp= (struct sockaddr_in *)dest_addr;
  84                 if (sinp->sin_family != AF_INET)
  85                 {
  86                         errno= EAFNOSUPPORT;
  87                         return -1;
  88                 }
  89         }
  90
  91         buflen= sizeof(*io_hdrp) + length;
  92         if (buflen < length)
  93         {
  94                 /* Overflow */
  95                 errno= EMSGSIZE;
  96                 return -1;
  97         }
  98         buf= malloc(buflen);
  99         if (buf == NULL)
 100                 return -1;
 101
 102         io_hdrp= buf;
 103         io_hdrp->uih_src_addr= 0;       /* Unused */
 104         io_hdrp->uih_src_port= 0;       /* Will cause error if NWUO_LP_ANY */
 105         if (udpoptp->nwuo_flags & NWUO_RA_ANY)
 106                 io_hdrp->uih_dst_addr= sinp->sin_addr.s_addr;
 107         else
 108                 io_hdrp->uih_dst_addr= 0;
 109         if (udpoptp->nwuo_flags & NWUO_RP_ANY)
 110                 io_hdrp->uih_dst_port= sinp->sin_port;
 111         else
 112                 io_hdrp->uih_dst_port= 0;
 113         io_hdrp->uih_ip_opt_len= 0;
 114         io_hdrp->uih_data_len= 0;
 115
 116         memcpy(&io_hdrp[1], message, length);
 117         r= write(socket, buf, buflen);
 118         if (r == -1)
 119         {
 120                 t_errno= errno;
 121                 free(buf);
 122                 errno= t_errno;
 123                 return -1;
 124         }
 125         assert(r == buflen);
 126         free(buf);
 127         return length;
 128 }
 129