dgclibcast6.lc

unix网络编程卷1：套接口API的全书源码

#include    "unp.h"##  1 ##src/bcast/dgclibcast6.c##

static void recvfrom_alarm(int);##  2 ##src/bcast/dgclibcast6.c##
static int pipefd[2];##  3 ##src/bcast/dgclibcast6.c##

void##  4 ##src/bcast/dgclibcast6.c##
dg_cli(FILE *fp, int sockfd, const SA *pservaddr, socklen_t servlen)##  5 ##src/bcast/dgclibcast6.c##
{##  6 ##src/bcast/dgclibcast6.c##
    int     n, maxfdp1;##  7 ##src/bcast/dgclibcast6.c##
    const int on = 1;##  8 ##src/bcast/dgclibcast6.c##
    char    sendline[MAXLINE], recvline[MAXLINE + 1];##  9 ##src/bcast/dgclibcast6.c##
    fd_set  rset;## 10 ##src/bcast/dgclibcast6.c##
    socklen_t len;## 11 ##src/bcast/dgclibcast6.c##
    struct sockaddr *preply_addr;## 12 ##src/bcast/dgclibcast6.c##

    preply_addr = Malloc(servlen);## 13 ##src/bcast/dgclibcast6.c##

    Setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on));## 14 ##src/bcast/dgclibcast6.c##

    Pipe(pipefd);## 15 ##src/bcast/dgclibcast6.c##
    maxfdp1 = max(sockfd, pipefd[0]) + 1;## 16 ##src/bcast/dgclibcast6.c##

    FD_ZERO(&rset);## 17 ##src/bcast/dgclibcast6.c##

    Signal(SIGALRM, recvfrom_alarm);## 18 ##src/bcast/dgclibcast6.c##

    while (Fgets(sendline, MAXLINE, fp) != NULL) {## 19 ##src/bcast/dgclibcast6.c##
        Sendto(sockfd, sendline, strlen(sendline), 0, pservaddr, servlen);## 20 ##src/bcast/dgclibcast6.c##

        alarm(5);## 21 ##src/bcast/dgclibcast6.c##
        for (;;) {## 22 ##src/bcast/dgclibcast6.c##
            FD_SET(sockfd, &rset);## 23 ##src/bcast/dgclibcast6.c##
            FD_SET(pipefd[0], &rset);## 24 ##src/bcast/dgclibcast6.c##
            if ((n = select(maxfdp1, &rset, NULL, NULL, NULL)) < 0) {## 25 ##src/bcast/dgclibcast6.c##
                if (errno == EINTR)## 26 ##src/bcast/dgclibcast6.c##
                    continue;## 27 ##src/bcast/dgclibcast6.c##
                else## 28 ##src/bcast/dgclibcast6.c##
                    err_sys("select error");## 29 ##src/bcast/dgclibcast6.c##
            }## 30 ##src/bcast/dgclibcast6.c##

            if (FD_ISSET(sockfd, &rset)) {## 31 ##src/bcast/dgclibcast6.c##
                len = servlen;## 32 ##src/bcast/dgclibcast6.c##
                n = Recvfrom(sockfd, recvline, MAXLINE, 0, preply_addr,## 33 ##src/bcast/dgclibcast6.c##
                             &len);## 34 ##src/bcast/dgclibcast6.c##
                recvline[n] = 0;    /* null terminate */## 35 ##src/bcast/dgclibcast6.c##
                printf("from %s: %s",## 36 ##src/bcast/dgclibcast6.c##
                       Sock_ntop_host(preply_addr, len), recvline);## 37 ##src/bcast/dgclibcast6.c##
            }## 38 ##src/bcast/dgclibcast6.c##

            if (FD_ISSET(pipefd[0], &rset)) {## 39 ##src/bcast/dgclibcast6.c##
                Read(pipefd[0], &n, 1); /* timer expired */## 40 ##src/bcast/dgclibcast6.c##
                break;## 41 ##src/bcast/dgclibcast6.c##
            }## 42 ##src/bcast/dgclibcast6.c##
        }## 43 ##src/bcast/dgclibcast6.c##
    }## 44 ##src/bcast/dgclibcast6.c##
}## 45 ##src/bcast/dgclibcast6.c##

static void## 46 ##src/bcast/dgclibcast6.c##
recvfrom_alarm(int signo)## 47 ##src/bcast/dgclibcast6.c##
{## 48 ##src/bcast/dgclibcast6.c##
    Write(pipefd[1], "", 1);    /* write 1 null byte to pipe */## 49 ##src/bcast/dgclibcast6.c##
    return;## 50 ##src/bcast/dgclibcast6.c##
}## 51 ##src/bcast/dgclibcast6.c##