?? sendto.c
字號(hào):
#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 0static 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;}
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