source: trunk/minix/lib/ip/sendto.c@ 10

#undef NDEBUG

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <net/gen/in.h>
#include <net/gen/udp.h>
#include <net/gen/udp_hdr.h>
#include <net/gen/udp_io.h>

#define DEBUG 0

static ssize_t _udp_sendto(int socket, const void *message, size_t length,
        int flags, const struct sockaddr *dest_addr, socklen_t dest_len,
        nwio_udpopt_t *udpoptp);

ssize_t sendto(int socket, const void *message, size_t length, int flags,
        const struct sockaddr *dest_addr, socklen_t dest_len)
{
        int r;
        nwio_udpopt_t udpopt;

        r= ioctl(socket, NWIOGUDPOPT, &udpopt);
        if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
        {
                if (r == -1)
                        return r;
                return _udp_sendto(socket, message, length, flags,
                        dest_addr, dest_len, &udpopt);
        }

#if DEBUG
        fprintf(stderr, "sendto: not implemented for fd %d\n", socket);
#endif
        errno= ENOSYS;
        return -1;
}

static ssize_t _udp_sendto(int socket, const void *message, size_t length,
        int flags, const struct sockaddr *dest_addr, socklen_t dest_len,
        nwio_udpopt_t *udpoptp)
{
        int r, t_errno;
        size_t buflen;
        void *buf;
        struct sockaddr_in *sinp;
        udp_io_hdr_t *io_hdrp;

        if (flags)
        {
#if DEBUG
                fprintf(stderr, "sendto(udp): flags not implemented\n");
#endif
                errno= ENOSYS;
                return -1;
        }

        if (udpoptp->nwuo_flags & NWUO_RWDATONLY)
                return write(socket, message, length);

        if ((udpoptp->nwuo_flags & NWUO_RP_ANY) ||
                (udpoptp->nwuo_flags & NWUO_RA_ANY))
        {
                /* Check destination address */
                if (dest_len < sizeof(*sinp))
                {
                        errno= EINVAL;
                        return -1;
                }
                sinp= (struct sockaddr_in *)dest_addr;
                if (sinp->sin_family != AF_INET)
                {
                        errno= EAFNOSUPPORT;
                        return -1;
                }
        }

        buflen= sizeof(*io_hdrp) + length;
        if (buflen < length)
        {       
                /* Overflow */
                errno= EMSGSIZE;
                return -1;
        }
        buf= malloc(buflen);
        if (buf == NULL)
                return -1;

        io_hdrp= buf;
        io_hdrp->uih_src_addr= 0;       /* Unused */
        io_hdrp->uih_src_port= 0;       /* Will cause error if NWUO_LP_ANY */
        if (udpoptp->nwuo_flags & NWUO_RA_ANY)
                io_hdrp->uih_dst_addr= sinp->sin_addr.s_addr;
        else
                io_hdrp->uih_dst_addr= 0;
        if (udpoptp->nwuo_flags & NWUO_RP_ANY)
                io_hdrp->uih_dst_port= sinp->sin_port;
        else
                io_hdrp->uih_dst_port= 0;
        io_hdrp->uih_ip_opt_len= 0;
        io_hdrp->uih_data_len= 0;

        memcpy(&io_hdrp[1], message, length);
        r= write(socket, buf, buflen);
        if (r == -1)
        {
                t_errno= errno;
                free(buf);
                errno= t_errno;
                return -1;
        }
        assert(r == buflen);
        free(buf);
        return length;
}