diff options
Diffstat (limited to 'tcp.c')
| -rw-r--r-- | tcp.c | 264 |
1 files changed, 264 insertions, 0 deletions
@@ -0,0 +1,264 @@ +/* + * Copyright (c) 1999-2003 Smithsonian Astrophysical Observatory + */ + +/* + * + * tcp.c -- unix tcp connection routines + * + */ +#if HAVE_CONFIG_H +#include <conf.h> +#endif + +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#if HAVE_STDLIB_H +#include <stdlib.h> +#endif +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <xport.h> +#include <tcp.h> + +/* the ever-present */ +#ifndef SZ_LINE +#define SZ_LINE 1024 +#endif + +/* name of user environment variable specifying this host */ +#ifndef MYHOST +#define MYHOST "XPA_HOST" +#endif + +/* other modules can set this variable and the default for various routines + will be "localhost" instead of the DNS-dependent hostname */ +int use_localhost=0; + +static char myhost[SZ_LINE]; /* hostname to registering access points */ + +/* + *---------------------------------------------------------------------------- + * + * + * Private Routines and Data + * + * + *---------------------------------------------------------------------------- + */ + +static char ipstr[SZ_LINE]; + +/* + *---------------------------------------------------------------------------- + * + * + * Public Routines + * + * + *---------------------------------------------------------------------------- + */ + +/* + *-------------------------------------------------------------- + * + * Routines: gethost + * + * Purpose: Find the current hostname + * + * Results: 1 on success, 0 for failure + * + *-------------------------------------------------------------- + */ +#ifdef ANSI_FUNC +int +gethost ( + char *xhost, /* (out) corresponding hostname */ + int len /* (in) length of host buffer */ +) +#else +int gethost(xhost, len) + char *xhost; /* (out) corresponding hostname */ + int len; /* (in) length of host buffer */ +#endif +{ + char *s=NULL; +#if HAVE_GETADDRINFO + struct addrinfo *hints=NULL, *addrinfo=NULL; +#else + struct hostent *hent; +#endif + static int init=0; + + if( use_localhost == 0 ){ + if( init == 0 ){ + if( (s=(char *)getenv(MYHOST)) != NULL ){ + strncpy(myhost, s, SZ_LINE-1); + } else { + gethostname(myhost, SZ_LINE-1); + } + init++; + } + strncpy(xhost, myhost, len-1); + +#if HAVE_GETADDRINFO + hints = (struct addrinfo *)calloc(1, sizeof(struct addrinfo)); + hints->ai_flags |= AI_CANONNAME; + hints->ai_family = AF_INET; + if( getaddrinfo(xhost, NULL, hints, &addrinfo) != 0 ){ + freeaddrinfo(addrinfo); + if( hints ) free(hints); + return -1; + } + strncpy(xhost, addrinfo->ai_canonname, len-1); + freeaddrinfo(addrinfo); + if( hints ) free(hints); +#else + if( (hent = gethostbyname(xhost)) == NULL ){ + return(-1); + } + strncpy(xhost, hent->h_name, len-1); +#endif + } + else{ + strncpy(xhost, "localhost", len-1); + } + xhost[len-1] = '\0'; + return(0); +} + +/* + *---------------------------------------------------------------------------- + * + * Routine: gethostip + * + * Purpose: Find the IP address corresponding to a hostname + * + * Results: ip (host byte order) on success, 0 if host is unknown + * + *--------------------------------------------------------------------------- + */ +#ifdef ANSI_FUNC +unsigned int +gethostip ( + char *xhost /* (in) Hostname (human readable) */ +) +#else +unsigned int gethostip(xhost) + char *xhost; /* (in) Hostname (human readable) */ +#endif +{ +#if HAVE_GETADDRINFO + struct addrinfo *hints=NULL, *addrinfo=NULL; + struct sockaddr_in * p; + int got; +#else + struct hostent *hostent; +#endif + unsigned int ip; + char temp[SZ_LINE]; + int saveip=0; + static unsigned int myip=0; + + /* null input means current host */ + if( (xhost == NULL) || (*xhost == '\0') || !strcmp(xhost, "$host") ){ + if( myip != 0 ) + return(myip); + saveip = 1; + gethost(temp, SZ_LINE); + } + else if( !strcmp(xhost, "$localhost") ){ + strcpy(temp, "localhost"); + } else { + strncpy(temp, xhost, SZ_LINE-1); + temp[SZ_LINE-1] = '\0'; + } + + /* special check */ + if( !strcmp(temp, "localhost") || !strcmp(temp, "localhost.localdomain") ){ + ip = htonl(0x7F000001); + goto done; + } + + /* + * Try looking by address (i.e., host is something like "128.84.253.1"). + * Do this first because it's much faster (no trip to the DNS) + */ + if( (int)(ip = inet_addr(temp)) != -1 ){ + goto done; + } + +#if HAVE_GETADDRINFO + /* + * Try looking it up by name. + */ + hints = (struct addrinfo *)calloc(1, sizeof(struct addrinfo)); + hints->ai_family = AF_INET; + got = getaddrinfo(temp, NULL, hints, &addrinfo); + if( got == 0 ){ + p = (struct sockaddr_in *)(addrinfo->ai_addr); + memcpy(&ip, &(p->sin_addr.s_addr), sizeof(p->sin_addr.s_addr)); + goto done; + } +#else + /* + * Try looking it up by name. If successful, the IP address is in + * hostent->h_addr_list[0] + */ + if( (hostent = gethostbyname(temp)) != NULL ){ + memcpy(&ip, hostent->h_addr_list[0], (size_t)hostent->h_length); + goto done; + } +#endif + /* could not convert */ + ip = 0; + saveip = 0; + +done: +#if HAVE_GETADDRINFO + freeaddrinfo(addrinfo); + if( hints ) free(hints); +#endif + ip = ntohl(ip); + if( saveip ) myip = ip; + return(ip); +} + +/* + *---------------------------------------------------------------------------- + * + * Routine: getiphost + * + * Purpose: Find the IP address in dot format corresponding to an ip + * + * Results: ip string (in static buffer) or NULL + * + *--------------------------------------------------------------------------- + */ +#ifdef ANSI_FUNC +char * +getiphost (unsigned int ip) +#else +char *getiphost(ip) + unsigned int ip; +#endif +{ + char *s; + struct sockaddr_in sockbuf; + + if( ip == 0x7F000001 ){ + strcpy(ipstr, "localhost"); + return(ipstr); + } + + sockbuf.sin_addr.s_addr = htonl(ip); + s = (char *)inet_ntoa(sockbuf.sin_addr); + if( s != NULL ){ + strcpy(ipstr, s); + return(ipstr); + } + else + return(NULL); +} |