UNP函数笔记十四: 带外数据

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第二十四章带外数据:

#include <sys/socket.h>int sockatmark(int sockfd);    have oob mark return 1, have not oob mark return 0, error return -1

示例:

#include <sys/ioctl.h>int sockatmark(int fd){    int        flag;    if (ioctl(fd, SIOCATMARK, &flag) == -1) {        return(-1);    }    return(flag != 0);}

#include "err_exit.h"#include "tcp_connect.h"int main(int argc, char ** argv){    int sockfd;    if (argc != 3) {        printf("usage: tcpsend01 <host> <port#>\n");        exit(1);    }    sockfd = tcp_connect(argv[1], argv[2]);    if (write(sockfd, "123", 3) != 3) {        err_exit("write error");    }    printf("wrote 3 bytes of normal data\n");    sleep(1);    if (send(sockfd, "4", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    sleep(1);    if (write(sockfd, "56", 2) != 2) {        err_exit("write error");    }    printf("wrote 2 bytes of normal data\n");    sleep(1);    if (send(sockfd, "7", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    sleep(1);    if (write(sockfd, "89", 2) != 2) {        err_exit("write error");    }    printf("wrote 2 bytes of normal data\n");    sleep(1);    exit(0);}

#include <fcntl.h>#include "err_exit.h"#include "my_signal.h"#include "tcp_listen.h"int listenfd;int connfd;void sig_urg(int signo){    int   n;    char  buff[100];    printf("SIGURG received\n");    if ((n = recv(connfd, buff, sizeof(buff)-1, MSG_OOB)) < 0) {        err_exit("recv error");    }    buff[n] = 0;  /* null terminate */    printf("read %d OOB byte: %s\n", n, buff);}int main(int argc, char ** argv){    int   n;    char  buff[100];    if (argc == 2) {        listenfd = tcp_listen(NULL, argv[1], NULL);    }    else if (argc == 3) {        listenfd = tcp_listen(argv[1], argv[2], NULL);    }    else {        printf("usage: tcprecv01 [ <host> ] <port#>\n");    }    if ((connfd = accept(listenfd, NULL, NULL)) == -1) {        err_exit("accept error");    }    if (my_signal(SIGURG, sig_urg) == SIG_ERR) {        err_exit("my_signal error");    }    if (fcntl(connfd, F_SETOWN, getpid()) == -1) {        err_exit("fcntl error");    }    for ( ; ; ) {        if ((n = read(connfd, buff, sizeof(buff)-1)) < 0) {            err_exit("read error");        }        else if (n == 0) {            printf("received EOF\n");            exit(0);        }        buff[n] = 0;  /* null terminate */        printf("read %d bytes: %s\n", n, buff);    }}

#include "err_exit.h"#include "tcp_listen.h"int main(int argc, char ** argv){    int     listenfd;    int     connfd;    int     n;    int     justreadoob = 0;    char    buff[100];    fd_set  rset;    fd_set  xset;    if (argc == 2) {        listenfd = tcp_listen(NULL, argv[1], NULL);    }    else if (argc == 3) {        listenfd = tcp_listen(argv[1], argv[2], NULL);    }    else {        printf("usage: tcprecv02 [ <host> ] <port#>\n");        exit(1);    }    if ((connfd = accept(listenfd, NULL, NULL)) == -1) {        err_exit("accept error");    }    FD_ZERO(&rset);    FD_ZERO(&xset);    for ( ; ; ) {        FD_SET(connfd, &rset);        if (justreadoob == 0) {            FD_SET(connfd, &xset);        }        if (select(connfd + 1, &rset, NULL, &xset, NULL) == -1) {            err_exit("select error");        }        if (FD_ISSET(connfd, &xset)) {            if ((n = recv(connfd, buff, sizeof(buff)-1, MSG_OOB)) < 0) {                err_exit("recv error");            }            buff[n] = 0;  /* null terminate */            printf("read %d OOB byte: %s\n", n, buff);            justreadoob = 1;            FD_CLR(connfd, &xset);        }        if (FD_ISSET(connfd, &rset)) {            if ((n = read(connfd, buff, sizeof(buff)-1)) < 0) {                err_exit("read error");            }            else if (n == 0) {                printf("received EOF\n");                exit(0);            }            buff[n] = 0;  /* null terminate */            printf("read %d bytes: %s\n", n, buff);            justreadoob = 0;        }    }}

#include "err_exit.h"#include "tcp_listen.h"int main(int argc, char ** argv){    int   listenfd;    int   connfd;    int   n;    int   on = 1;    char  buff[100];    if (argc == 2) {        listenfd = tcp_listen(NULL, argv[1], NULL);    }    else if (argc == 3) {        listenfd = tcp_listen(argv[1], argv[2], NULL);    }    else {        printf("usage: tcprecv02 [ <host> ] <port#>\n");        exit(1);    }    if (setsockopt(listenfd, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) == -1) {        err_exit("setsockopt error");    }    if ((connfd = accept(listenfd, NULL, NULL)) == -1) {        err_exit("accept error");    }    sleep(5);    for ( ; ; ) {        if ((n = sockatmark(connfd)) == -1) {            err_exit("sockatmark error");        }        else if (n == 1) {            printf("at OOB mark\n");        }        if ((n = read(connfd, buff, sizeof(buff)-1)) < 0) {            err_exit("read error");        }        else if (n == 0) {            printf("received EOF\n");            exit(0);        }        buff[n] = 0;  /* null terminate */        printf("read %d bytes: %s\n", n, buff);    }}

#include "err_exit.h"#include "tcp_connect.h"int main(int argc, char ** argv){    int sockfd;    if (argc != 3) {        printf("usage: tcpsend01 <host> <port#>\n");        exit(1);    }    sockfd = tcp_connect(argv[1], argv[2]);    if (write(sockfd, "123", 3) != 3) {        err_exit("write error");    }    printf("wrote 3 bytes of normal data\n");    if (send(sockfd, "4", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    if (write(sockfd, "5", 1) != 1) {        err_exit("write error");    }    printf("wrote 1 bytes of normal data\n");    exit(0);}

#include "err_exit.h"#include "tcp_connect.h"int main(int argc, char ** argv){    int sockfd;    if (argc != 3) {        printf("usage: tcpsend01 <host> <port#>\n");        exit(1);    }    sockfd = tcp_connect(argv[1], argv[2]);    if (write(sockfd, "123", 3) != 3) {        err_exit("write error");    }    printf("wrote 3 bytes of normal data\n");    sleep(1);    if (send(sockfd, "4", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    sleep(1);    if (write(sockfd, "5", 1) != 1) {        err_exit("write error");    }    printf("wrote 1 bytes of normal data\n");    sleep(1);    if (send(sockfd, "6", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    sleep(1);    if (write(sockfd, "7", 1) != 1) {        err_exit("write error");    }    printf("wrote 1 bytes of normal data\n");    sleep(1);    exit(0);}

#include <fcntl.h>#include "err_exit.h"#include "my_signal.h"#include "tcp_listen.h"int listenfd;int connfd;void sig_urg(int signo){    int   n;    char  buff[2048];    printf("SIGURG received\n");    if ((n = recv(connfd, buff, sizeof(buff)-1, MSG_OOB)) < 0) {        err_exit("recv error");    }    buff[n] = 0;  /* null terminate */    printf("read %d OOB byte: %s\n", n, buff);}int main(int argc, char ** argv){    int size = 4096;    if (argc == 2) {        listenfd = tcp_listen(NULL, argv[1], NULL);    }    else if (argc == 3) {        listenfd = tcp_listen(argv[1], argv[2], NULL);    }    else {        printf("usage: tcprecv01 [ <host> ] <port#>\n");    }    if (setsockopt(listenfd, SOL_SOCKET, SO_RCVBUF, &size,                    sizeof(size)) == -1) {        err_exit("setsockopt error");    }    if ((connfd = accept(listenfd, NULL, NULL)) == -1) {        err_exit("accept error");    }    if (my_signal(SIGURG, sig_urg) == SIG_ERR) {        err_exit("my_signal error");    }    if (fcntl(connfd, F_SETOWN, getpid()) == -1) {        err_exit("fcntl error");    }    for ( ; ; ) {        pause();    }}

#include "err_exit.h"#include "tcp_connect.h"int main(int argc, char ** argv){    int   sockfd;    int   size;    char  buff[16384];    if (argc != 3) {        printf("usage: tcpsend01 <host> <port#>\n");        exit(1);    }    sockfd = tcp_connect(argv[1], argv[2]);    size = 32768;    if (setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)) == -1) {        err_exit("setsockopt error");    }    if (write(sockfd, buff, 16384) != 16384) {        err_exit("write error");    }    printf("wrote 16384 bytes of normal data\n");    sleep(5);    if (send(sockfd, "a", 1, MSG_OOB) != 1) {        err_exit("send error");    }    printf("wrote 1 byte of OOB data\n");    if (write(sockfd, buff, 1024) != 1024) {        err_exit("write error");    }    printf("wrote 1024 bytes of normal data\n");    exit(0);}

#include <fcntl.h>#include <sys/socket.h>#include "err_exit.h"#include "my_signal.h"static int  servfd;static int  nsec;         /* seconds betweeen each alarm */static int  maxnprobes;   /* probes w/no response before quit */static int  nprobes;      /* probes since last server response */void sig_urg(int signo){    int   n;    char  c;     if ((n = recv(servfd, &c, 1, MSG_OOB)) < 0) {        if (errno != EWOULDBLOCK) {            err_exit("recv error");        }    }    nprobes = 0;  /* reset counter */    return;  /* may interrupt client code */}void sig_alrm(int signo){    if (++nprobes > maxnprobes) {        fprintf(stderr, "server is unreachable\n");        exit(0);    }    if (send(servfd, "1", 1, MSG_OOB) != 1) {        err_exit("send error");    }    alarm(nsec);    return;  /* may interrupt client code */}void heartbeat_cli(int servfd_arg, int nsec_arg, int maxnprobes_arg){    servfd = servfd_arg;  /* set globals for signal handlers */    if ((nsec = nsec_arg) < 1) {        nsec = 1;    }    if ((maxnprobes = maxnprobes_arg) < nsec) {        maxnprobes = nsec;    }    nprobes = 0;    if (my_signal(SIGURG, sig_urg) == SIG_ERR) {        err_exit("my_signal error");    }    if (fcntl(servfd, F_SETOWN, getpid()) == -1) {        err_exit("fcntl error");    }    if (my_signal(SIGALRM, sig_alrm) == SIG_ERR) {        err_exit("my_signal error");    }    alarm(nsec);}

#include <fcntl.h>#include <sys/socket.h>#include "err_exit.h"#include "my_signal.h"static int  servfd;static int  nsec;        /* seconds between each alarm */static int  maxnalarms;  /* alarms w/no client probe before quit */static int  nprobes;     /* alarms since last client probe */void sig_urg(int signo){    int   n;    char  c;    if ((n = recv(servfd, &c, 1, MSG_OOB)) < 0) {        if (errno != EWOULDBLOCK) {            err_exit("recv error");        }    }    if (send(servfd, &c, 1, MSG_OOB) != 1) {  /* echo back out-of-band byte */        err_exit("send error");    }    nprobes = 0;  /* reset counter */    return;  /* may interrupt server code */}void sig_alrm(int signo){    if (++nprobes > maxnalarms) {        printf("no probes from client\n");        exit(0);    }    alarm(nsec);    return;  /* may interrupt server code */}voidheartbeat_serv(int servfd_arg, int nsec_arg, int maxnalarms_arg){    servfd = servfd_arg;  /* set globals for signal handlers */    if ((nsec = nsec_arg) < 1) {        nsec = 1;    }    if ((maxnalarms = maxnalarms_arg) < nsec) {        maxnalarms = nsec;    }    nprobes = 0;    if (my_signal(SIGURG, sig_urg) == SIG_ERR) {        err_exit("my_signal error");    }    if (fcntl(servfd, F_SETOWN, getpid()) == -1) {        err_exit("fcntl error");    }    if (my_signal(SIGALRM, sig_alrm) == SIG_ERR) {        err_exit("my_signal error");    }    alarm(nsec);}