TCPIP详解SOCK程序源码

/* -*- c-basic-offset: 8; -*- * * Copyright (c) 1993 W. Richard Stevens. All rights reserved. * Permission to use or modify this software and its documentation only for * educational purposes and without fee is hereby granted, provided that * the above copyright notice appear in all copies. The author makes no * representations about the suitability of this software for any purpose. * It is provided "as is" without express or implied warranty. */ #include <stdio.h> #include <netdb.h> #include <sys/types.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #ifdef HAVE_GETOPT_H #include <getopt.h> #endif #include <string.h> #include "sock.h" char *host; /* hostname or dotted-decimal string */ char *port; /* DefinE global variables */ int bindport; /* 0 or TCP or UDP port number to bind */ /* set by -b or -l options */ int broadcast; /* SO_BROADCAST */ int cbreak; /* set terminal to cbreak mode */ int chunkwrite; /* write in small chunks; not all-at-once */ int client = 1; /* acting as client is the default */ int connectudp = 1; /* connect UDP client */ int crlf; /* convert newline to CR/LF & vice versa */ int debug; /* SO_DEBUG */ int dofork; /* concurrent server, do a fork() */ int dontroute; /* SO_DONTROUTE */ char foreignip[32]; /* foreign IP address, dotted-decimal string */ int foreignport; /* foreign port number */ int halfclose; /* TCP half close option */ int ignorewerr; /* true if write() errors should be ignored */ int iptos = -1; /* IP_TOS opton */ int ipttl = -1; /* IP_TTL opton */ char joinip[32]; /* multicast IP address, dotted-decimal string */ int keepalive; /* SO_KEEPALIVE */ long linger = -1; /* 0 or positive turns on option */ int listenq = 5; /* listen queue for TCP Server */ char localip[32]; /* local IP address, dotted-decimal string */ int maxseg; /* TCP_MAXSEG */ int mcastttl; /* multicast TTL */ int msgpeek; /* MSG_PEEK */ int nodelay; /* TCP_NODELAY (Nagle algorithm) */ int nbuf = 1024; /* number of buffers to write (sink mode) */ int onesbcast; /* set IP_ONESBCAST for 255.255.255.255 bcasts */ int pauseclose; /* #ms to sleep after recv FIN, before close */ int pauseinit; /* #ms to sleep before first read */ int pauselisten; /* #ms to sleep after listen() */ int pauserw; /* #ms to sleep before each read or write */ int reuseaddr; /* SO_REUSEADDR */ int reuseport; /* SO_REUSEPORT */ int readlen = 1024; /* default read length for socket */ int writelen = 1024; /* default write length for socket */ int recvdstaddr; /* IP_RECVDSTADDR option */ int rcvbuflen; /* size for SO_RCVBUF */ int sndbuflen; /* size for SO_SNDBUF */ long rcvtimeo; /* SO_RCVTIMEO */ long sndtimeo; /* SO_SNDTIMEO */ int sroute_cnt; /* count of #IP addresses in route */ char *rbuf; /* pointer that is malloc'ed */ char *wbuf; /* pointer that is malloc'ed */ int server; /* to act as server requires -s option */ int sigio; /* send SIGIO */ int sourcesink; /* source/sink mode */ int udp; /* use UDP instead of TCP */ int urgwrite; /* write urgent byte after this write */ int verbose; /* each -v increments this by 1 */ int usewritev; /* use writev() instead of write() */ struct sockaddr_in cliaddr, servaddr; static void usage(const char *); int main(int argc, char *argv[]) { int c, fd; char *ptr; if (argc < 2) usage(""); opterr = 0; /* don't want getopt() writing to stderr */ while ( (c = getopt(argc, argv, "2b:cf:g:hij:kl:n:op:q:r:st:uvw:x:y:ABCDEFG:H:IJ:KL:NO:P:Q:R:S:TU:VWX:YZ")) != -1) { switch (c) { #ifdef IP_ONESBCAST case '2': /* use 255.255.255.255 as broadcast address */ onesbcast = 1; break; #endif case 'b': bindport = atoi(optarg); break; case 'c': /* convert newline to CR/LF & vice versa */ crlf = 1; break; case 'f': /* foreign IP address and port#: a.b.c.d.p */ if ( (ptr = strrchr(optarg, '.')) == NULL) usage("invalid -f option"); *ptr++ = 0; /* null replaces final period */ foreignport = atoi(ptr); /* port number */ strcpy(foreignip, optarg); /* save dotted-decimal IP */ break; case 'g': /* loose source route */ sroute_doopt(0, optarg); break; case 'h': /* TCP half-close option */ halfclose = 1; break; case 'i': /* source/sink option */ sourcesink = 1; break; #ifdef IP_ADD_MEMBERSHIP case 'j': /* join multicast group a.b.c.d */ strcpy(joinip, optarg); /* save dotted-decimal IP */ break; #endif case 'k': /* chunk-write option */ chunkwrite = 1; break; case 'l': /* local IP address and port#: a.b.c.d.p */ if ( (ptr = strrchr(optarg, '.')) == NULL) usage("invalid -l option"); *ptr++ = 0; /* null replaces final period */ bindport = atoi(ptr); /* port number */ strcpy(localip, optarg); /* save dotted-decimal IP */ break; case 'n': /* number of buffers to write */ nbuf = atol(optarg); break; case 'o': /* do not connect UDP client */ connectudp = 0; break; case 'p': /* pause before each read or write */ pauserw = atoi(optarg); break; case 'q': /* listen queue for TCP server */ listenq = atoi(optarg); break; case 'r': /* read() length */ readlen = atoi(optarg); break; case 's': /* server */ server = 1; client = 0; break; #ifdef IP_MULTICAST_TTL case 't': /* IP_MULTICAST_TTL */ mcastttl = atoi(optarg); break; #endif case 'u': /* use UDP instead of TCP */ udp = 1; break; case 'v': /* output what's going on */ verbose++; break; case 'w': /* write() length */ writelen = atoi(optarg); break; case 'x': /* SO_RCVTIMEO socket option */ rcvtimeo = atol(optarg); break; case 'y': /* SO_SNDTIMEO socket option */ sndtimeo = atol(optarg); break; case 'A': /* SO_REUSEADDR socket option */ reuseaddr = 1; break; case 'B': /* SO_BROADCAST socket option */ broadcast = 1; break; case 'C': /* set standard input to cbreak mode */ cbreak = 1; break; case 'D': /* SO_DEBUG socket option */ debug = 1; break; case 'E': /* IP_RECVDSTADDR socket option */ recvdstaddr = 1; break; case 'F': /* concurrent server, do a fork() */ dofork = 1; break; case 'G': /* strict source route */ sroute_doopt(1, optarg); break; #ifdef IP_TOS case 'H': /* IP_TOS socket option */ iptos = atoi(optarg); break; #endif case 'I': /* SIGIO signal */ sigio = 1; break; #ifdef IP_TTL case 'J': /* IP_TTL socket option */ ipttl = atoi(optarg); break; #endif case 'K': /* SO_KEEPALIVE socket option */ keepalive = 1; break; case 'L': /* SO_LINGER socket option */ linger = atol(optarg); break; case 'N': /* SO_NODELAY socket option */ nodelay = 1; break; case 'O': /* pause before listen(), before first accept() */ pauselisten = atoi(optarg); break; case 'P': /* pause before first read() */ pauseinit = atoi(optarg); break; case 'Q': /* pause after receiving FIN, but before close() */ pauseclose = atoi(optarg); break; case 'R': /* SO_RCVBUF socket option */ rcvbuflen = atoi(optarg); break; case 'S': /* SO_SNDBUF socket option */ sndbuflen = atoi(optarg); break; #ifdef SO_REUSEPORT case 'T': /* SO_REUSEPORT socket option */ reuseport = 1; break; #endif case 'U': /* when to write urgent byte */ urgwrite = atoi(optarg); break; case 'V': /* use writev() instead of write() */ usewritev = 1; chunkwrite = 1; /* implies this option too */ break; case 'W': /* ignore write errors */ ignorewerr = 1; break; case 'X': /* TCP maximum segment size option */ maxseg = atoi(optarg); break; case 'Y': /* SO_DONTROUTE socket option */ dontroute = 1; break; case 'Z': /* MSG_PEEK option */