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- /*
- * Copyright (c) 1985 Regents of the University of California.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are permitted provided
- * that: (1) source distributions retain this entire copyright notice and
- * comment, and (2) distributions including binaries display the following
- * acknowledgement: ``This product includes software developed by the
- * University of California, Berkeley and its contributors'' in the
- * documentation or other materials provided with the distribution and in
- * all advertising materials mentioning features or use of this software.
- * Neither the name of the University nor the names of its contributors may
- * be used to endorse or promote products derived from this software without
- * specific prior written permission.
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- */
-
- #if defined(LIBC_SCCS) && !defined(lint)
- static char sccsid[] = "@(#)res_comp.c 6.18 (Berkeley) 6/27/90";
- #endif /* LIBC_SCCS and not lint */
-
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <time.h>
-
- #include "netdb.h"
- #include "resolve.h"
- #include "nameser.h"
- #include "in.h"
- #include "socket.h"
-
- static int dn_find(u_char *exp_dn, u_char *msg,
- u_char **dnptrs, u_char **lastdnptr);
-
- /*
- * Expand compressed domain name 'comp_dn' to full domain name.
- * 'msg' is a pointer to the begining of the message,
- * 'eomorig' points to the first location after the message,
- * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
- * Return size of compressed name or -1 if there was an error.
- */
- int
- dn_expand(msg, eomorig, comp_dn, exp_dn, length)
- u_char *msg, *eomorig, *comp_dn, *exp_dn;
- int length;
- {
- register u_char *cp, *dn;
- register int n, c;
- u_char *eom;
- int len = -1, checked = 0;
-
- dn = exp_dn;
- cp = comp_dn;
- eom = exp_dn + length;
- /*
- * fetch next label in domain name
- */
- while (n = *cp++) {
- /*
- * Check for indirection
- */
- switch (n & INDIR_MASK) {
- case 0:
- if (dn != exp_dn) {
- if (dn >= eom)
- return (-1);
- *dn++ = '.';
- }
- if (dn+n >= eom)
- return (-1);
- checked += n + 1;
- while (--n >= 0) {
- if ((c = *cp++) == '.') {
- if (dn + n + 2 >= eom)
- return (-1);
- *dn++ = '\\';
- }
- *dn++ = c;
- if (cp >= eomorig) /* out of range */
- return(-1);
- }
- break;
-
- case INDIR_MASK:
- if (len < 0)
- len = cp - comp_dn + 1;
- cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff));
- if (cp < msg || cp >= eomorig) /* out of range */
- return(-1);
- checked += 2;
- /*
- * Check for loops in the compressed name;
- * if we've looked at the whole message,
- * there must be a loop.
- */
- if (checked >= eomorig - msg)
- return (-1);
- break;
-
- default:
- return (-1); /* flag error */
- }
- }
- *dn = '\0';
- if (len < 0)
- len = cp - comp_dn;
- return (len);
- }
-
- /*
- * Compress domain name 'exp_dn' into 'comp_dn'.
- * Return the size of the compressed name or -1.
- * 'length' is the size of the array pointed to by 'comp_dn'.
- * 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]
- * is a pointer to the beginning of the message. The list ends with NULL.
- * 'lastdnptr' is a pointer to the end of the arrary pointed to
- * by 'dnptrs'. Side effect is to update the list of pointers for
- * labels inserted into the message as we compress the name.
- * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
- * is NULL, we don't update the list.
- */
- int
- dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
- u_char *exp_dn, *comp_dn;
- int length;
- u_char **dnptrs, **lastdnptr;
- {
- register u_char *cp, *dn;
- register int c, l;
- u_char **cpp, **lpp, *sp, *eob;
- u_char *msg;
-
- dn = exp_dn;
- cp = comp_dn;
- eob = cp + length;
- if (dnptrs != NULL) {
- if ((msg = *dnptrs++) != NULL) {
- for (cpp = dnptrs; *cpp != NULL; cpp++)
- ;
- lpp = cpp; /* end of list to search */
- }
- } else
- msg = NULL;
- for (c = *dn++; c != '\0'; ) {
- /* look to see if we can use pointers */
- if (msg != NULL) {
- if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {
- if (cp+1 >= eob)
- return (-1);
- *cp++ = (l >> 8) | INDIR_MASK;
- *cp++ = l % 256;
- return (cp - comp_dn);
- }
- /* not found, save it */
- if (lastdnptr != NULL && cpp < lastdnptr-1) {
- *cpp++ = cp;
- *cpp = NULL;
- }
- }
- sp = cp++; /* save ptr to length byte */
- do {
- if (c == '.') {
- c = *dn++;
- break;
- }
- if (c == '\\') {
- if ((c = *dn++) == '\0')
- break;
- }
- if (cp >= eob) {
- if (msg != NULL)
- *lpp = NULL;
- return (-1);
- }
- *cp++ = c;
- } while ((c = *dn++) != '\0');
- /* catch trailing '.'s but not '..' */
- if ((l = cp - sp - 1) == 0 && c == '\0') {
- cp--;
- break;
- }
- if (l <= 0 || l > MAXLABEL) {
- if (msg != NULL)
- *lpp = NULL;
- return (-1);
- }
- *sp = l;
- }
- if (cp >= eob) {
- if (msg != NULL)
- *lpp = NULL;
- return (-1);
- }
- *cp++ = '\0';
- return (cp - comp_dn);
- }
-
- /*
- * Skip over a compressed domain name. Return the size or -1.
- */
- int
- dn_skipname(comp_dn, eom)
- u_char *comp_dn, *eom;
- {
- register u_char *cp;
- register int n;
-
- cp = comp_dn;
- while (cp < eom && (n = *cp++)) {
- /*
- * check for indirection
- */
- switch (n & INDIR_MASK) {
- case 0: /* normal case, n == len */
- cp += n;
- continue;
- default: /* illegal type */
- return (-1);
- case INDIR_MASK: /* indirection */
- cp++;
- }
- break;
- }
- return (cp - comp_dn);
- }
-
- /*
- * Search for expanded name from a list of previously compressed names.
- * Return the offset from msg if found or -1.
- * dnptrs is the pointer to the first name on the list,
- * not the pointer to the start of the message.
- */
- static int
- dn_find(exp_dn, msg, dnptrs, lastdnptr)
- u_char *exp_dn, *msg;
- u_char **dnptrs, **lastdnptr;
- {
- register u_char *dn, *cp, **cpp;
- register int n;
- u_char *sp;
-
- for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
- dn = exp_dn;
- sp = cp = *cpp;
- while (n = *cp++) {
- /*
- * check for indirection
- */
- switch (n & INDIR_MASK) {
- case 0: /* normal case, n == len */
- while (--n >= 0) {
- if (*dn == '.')
- goto next;
- if (*dn == '\\')
- dn++;
- if (*dn++ != *cp++)
- goto next;
- }
- if ((n = *dn++) == '\0' && *cp == '\0')
- return (sp - msg);
- if (n == '.')
- continue;
- goto next;
-
- default: /* illegal type */
- return (-1);
-
- case INDIR_MASK: /* indirection */
- cp = msg + (((n & 0x3f) << 8) | *cp);
- }
- }
- if (*dn == '\0')
- return (sp - msg);
- next: ;
- }
- return (-1);
- }
-
- /*
- * Routines to insert/extract short/long's. Must account for byte
- * order and non-alignment problems. This code at least has the
- * advantage of being portable.
- *
- * used by sendmail.
- */
-
- u_short
- _getshort(msgp)
- u_char *msgp;
- {
- register u_char *p = (u_char *) msgp;
- #ifdef vax
- /*
- * vax compiler doesn't put shorts in registers
- */
- register u_long u;
- #else
- register u_short u;
- #endif
-
- u = *p++ << 8;
- return ((u_short)(u | *p));
- }
-
- u_long
- _getlong(msgp)
- u_char *msgp;
- {
- register u_char *p = (u_char *) msgp;
- register u_long u;
-
- u = *p++; u <<= 8;
- u |= *p++; u <<= 8;
- u |= *p++; u <<= 8;
- return (u | *p);
- }
-
-
- putshort(s, msgp)
- register u_short s;
- register u_char *msgp;
- {
-
- msgp[1] = s;
- msgp[0] = s >> 8;
- }
-
- putlong(l, msgp)
- register u_long l;
- register u_char *msgp;
- {
-
- msgp[3] = l;
- msgp[2] = (l >>= 8);
- msgp[1] = (l >>= 8);
- msgp[0] = l >> 8;
- }
-
-
-
- static struct cache_s {
- void *key;
- int type;
- int len;
- struct hostent *cont;
- time_t expires;
- time_t accessed;
- } *cache = 0;
-
- unsigned int cachesize = 0;
-
-
- static void kill_cache( struct cache_s *entry )
- {
- if( ! entry->key ) return;
- free( entry->key );
- entry->cont = NULL;
- entry->key = NULL;
- }
-
-
- static int he_size( struct hostent *he )
- {
- int size;
- char **cp;
- struct mx_data **mx;
-
- if( !he ) return 0;
- size = sizeof( struct hostent ) + 2*sizeof(char *) + ((strlen(he->h_name)+4)&~3) + sizeof(struct mx_data *);
- for( cp=he->h_aliases; *cp; cp++ ) size += sizeof(char *) + strlen(*cp)+1;
- for( cp=he->h_addr_list; *cp; cp++ ) size += sizeof(char *) + he->h_length;
- for( mx=he->h_mx; *mx; mx++ ) size += sizeof(struct mx_data) + strlen((*mx)->host) + sizeof(struct mx_data *) + 1;
- return size;
- }
-
-
- static struct hostent *he_copy( char *mem, struct hostent *he )
- {
- struct hostent *new;
- int i;
- char **cp;
- char **ds;
- struct mx_data **mx,**xd;
-
- if( !he ) return NULL;
- new = (struct hostent *)mem;
- memcpy( new, he, sizeof(*new) );
- mem += sizeof(*new);
- for( cp=he->h_aliases,i=1; *cp; cp++,i++ );
- new->h_aliases = (char **)mem;
- mem += i*sizeof(char *);
- for( cp=he->h_addr_list,i=1; *cp; cp++,i++ );
- new->h_addr_list = (char **)mem;
- mem += i*sizeof(char *);
- for( mx=he->h_mx,i=1; *mx; mx++,i++ );
- new->h_mx = (struct mx_data **)mem;
- mem += i*sizeof(struct mx_data *);
- for( mx=new->h_mx; i>1; i--,mx++,mem+=sizeof(struct mx_data) ) *mx = (struct mx_data *)mem;
- *mx = NULL;
-
- strcpy( mem, he->h_name );
- new->h_name = mem;
- mem += ((strlen( he->h_name ) + 4)&~3);
-
- for( ds=new->h_addr_list,cp=he->h_addr_list; *cp; cp++,ds++ ) {
- *ds = mem;
- memcpy( mem, *cp, he->h_length );
- mem += he->h_length;
- }
- *ds = NULL;
-
- for( ds=new->h_aliases,cp=he->h_aliases; *cp; cp++,ds++ ) {
- *ds = mem;
- i = strlen( *cp ) +1;
- memcpy( mem, *cp, i );
- mem += i;
- }
- *ds = NULL;
-
- for( xd=new->h_mx,mx=he->h_mx; *mx; mx++,xd++ ) {
- (*xd)->preference = (*mx)->preference;
- (*xd)->host = (char *)mem;
- i = strlen( (*mx)->host) + 1;
- memcpy( mem, (*mx)->host, i );
- mem += i;
- }
- *xd = NULL;
-
- return new;
- }
-
-
- extern int cache_req( void *, int, int , struct hostent ** );
- int cache_req( void *data, int type, int len, struct hostent **rval )
- {
- struct cache_s *find;
- int i;
- time_t t;
-
- for( find=cache,i=cachesize; i; i--,find++ ) {
- if( (find->key) && (find->type==type) && (find->len==len) && ! memcmp( find->key, data, len ) ) {
- time( &t );
- if( difftime( t, find->expires ) >= 0 ) kill_cache( find );
- else {
- *rval = find->cont;
- find->accessed = time(NULL);
- return 0;
- }
- }
- }
-
- return -1;
- }
-
-
- void cache_it( void *data, int type, int len, struct hostent *result, long ttl )
- {
- struct cache_s *overw=NULL, *clear=NULL;
- int i;
- time_t min;
- char *mem;
-
- if (ttl == 0)
- return;
-
- time(&min);
- for( overw=cache,i=cachesize; i; i--,overw++ ) if( overw->key && difftime(min,overw->expires)<0 ) {
- if( overw->type==type && overw->len==len && ! memcmp( overw->key, data, len ) ) break;
- }
- else clear = overw;
- if( !i ) overw = clear;
- if( ! overw ) for( overw=cache,clear=&cache[1],i=cachesize-1,min=cache->accessed; i; i--,clear++ )
- if( difftime( clear->accessed, min ) < 0 ) {
- overw = clear;
- min = clear->accessed;
- }
-
- mem = malloc( len+he_size(result)+3 );
- if( ! mem ) return;
- kill_cache( overw );
- memcpy( mem, data, len );
- overw->key = mem;
- overw->type = type;
- overw->len = len;
- overw->accessed = time( NULL );
- overw->expires = overw->accessed + ttl;
- len = (len+3)&~3;
- overw->cont = he_copy( mem+len, result );
- }
-
-
- void cache_save( void )
- {
- FILE *f;
- int i;
- int n;
- struct cache_s *cs;
- char **cp;
- struct mx_data **mx;
- unsigned char *addr;
-
- f = fopen( "<TCPIP$dir>.resolve.cache", "w" );
- if( ! f ) return;
- for( n=cachesize,cs=cache; n; n--,cs++ ) if( cs->key ) {
- switch( cs->type ) {
- case CACHE_MX:
- fprintf( f, "MX " );
- goto keysave;
- case CACHE_NAME:
- fprintf( f, "NAME " );
- keysave:
- fwrite( cs->key, cs->len, 1, f );
- fprintf( f, "\n" );
- break;
- case CACHE_ADDR:
- if (cs->len != 4)
- break;
- addr = (unsigned char *)cs->key;
- fprintf( f, "ADDR %d.%d.%d.%d\n", addr[3], addr[2], addr[1], addr[0] );
- break;
- }
- fprintf( f, "%d %d\n", cs->expires, cs->accessed );
- if( cs->cont ) {
- for( mx=cs->cont->h_mx; *mx; mx++ ) {
- fprintf( f, "%s", (*mx)->host );
- if( mx[1] ) fputc( ' ', f );
- }
- fputc( '\n', f );
- fprintf( f, "%d\n%s\n%d\n", cs->cont->h_length, cs->cont->h_name, cs->cont->h_addrtype );
- for( cp=cs->cont->h_aliases; *cp; cp++ ) fprintf( f, "%s ", *cp );
- fputc( '\n', f );
- for( cp=cs->cont->h_addr_list; *cp; cp++ ) {
- for( i=cs->cont->h_length; i; i-- ) fprintf( f, "%d.", (*(unsigned char **)cp)[i-1] );
- fputc( ' ', f );
- }
- fputc( '\n', f );
- }
- else fprintf( f, "\n%d\n",
- 0 );
- if( n>1 ) fputc( '\n', f );
- }
- fclose( f );
- }
-
-
- void cache_restore( void )
- {
- unsigned int addr[4];
- char buffer[500];
- char hostname[256];
- char addrs[100];
- char aliases[500];
- char mxhosts[500];
- struct mx_data mxdata[30];
- struct mx_data *mxptr[30];
- struct mx_data **mxpp;
- unsigned char key[256];
- struct hostent he;
- char *p_aliases[30];
- char *p_addrs[35];
- char *next;
- char **at;
- char *nextabyte;
- FILE *f;
- struct cache_s *c;
- int i,j;
- int n;
- struct hostent *ohe;
-
- f = fopen( "<TCPIP$dir>.resolve.cache", "r" );
- if( ! f ) return;
- cache_purge();
- he.h_aliases = p_aliases;
- he.h_addr_list = p_addrs;
- he.h_mx = mxptr;
- for( i=cachesize,c=cache; i && ! feof(f) && ! ferror(f); i--,c++ ) {
-
- c->cont = NULL;
- fgets( buffer, 255, f );
- if( ! memcmp( buffer, "NAME ", 5 ) ) {
- c->type = CACHE_NAME;
- memcpy( key, &buffer[5], strlen(buffer)-4 );
- c->len = strlen( (char *)key );
- if( key[c->len-1] == '\n' ) c->len--;
- }
- else if( ! memcmp( buffer, "MX ", 3 ) ) {
- c->type = CACHE_MX;
- memcpy( key, &buffer[3], strlen(buffer)-2 );
- c->len = strlen( (char *)key );
- if( key[c->len-1] == '\n' ) c->len--;
- }
- else if( ! memcmp( buffer, "ADDR ", 5 ) ) {
- c->type = CACHE_ADDR;
- c->len = sscanf( buffer, "ADDR %u.%u.%u.%u", &addr[3], &addr[2], &addr[1], &addr[0]);
- *(unsigned int *)(key) = addr[0] | (addr[1] << 8) | (addr[2] << 16) | (addr[3] << 24);
- }
- else break;
-
- fgets( buffer, 255, f );
- if( sscanf( buffer, "%d %d", &c->expires, &c->accessed ) < 2 ) break;
-
- fgets( mxhosts, 499, f );
- mxpp = mxptr;
- for( j=0,next=mxhosts; *next != '\n' && *next; j++, mxpp++ ) {
- while( *next == ' ' || *next == '\t' ) next++;
- if( ! *next || *next == '\n' ) break;
- *mxpp = &mxdata[j];
- (*mxpp)->preference = j;
- (*mxpp)->host = next;
- while( *next != ' ' && *next && *next != '\t' && *next != '\n' ) next++;
- if( *next == '\n' ) *next = 0;
- else *(next++) = 0;
- }
- *mxpp = NULL;
-
- fgets( buffer, 255, f );
- if( sscanf( buffer, "%d", &he.h_length ) < 1 ) break;
- if( he.h_length ) ohe = &he; else ohe = NULL;
-
- if( ohe ) {
- fgets( hostname, 255, f );
- if( hostname[strlen(hostname)-1] == '\n' ) hostname[strlen(hostname)-1] = 0;
- he.h_name = hostname;
-
- fgets( buffer, 255, f );
- if( sscanf( buffer, "%d", &he.h_addrtype ) < 1 ) break;
-
- fgets( aliases, 499, f );
- next = aliases;
- for( n=29,at=he.h_aliases; n; at++,n-- ) {
- while( *next==' ' || *next=='\t' ) next++;
- if( *next=='\n' || *next==0 ) break;
- *at = next;
- while( *next != ' ' && *next && *next != '\t' && *next != '\n' ) next++;
- *(next++) = 0;
- }
- *at = NULL;
-
- fgets( buffer, 499, f );
- for( nextabyte=addrs,next=buffer,n=100,at=he.h_addr_list; n; n--,at++,nextabyte+=he.h_length ) {
- while( *next==' ' || *next=='\t' ) next++;
- if( *next=='\n' || *next==0 ) break;
- *at = nextabyte;
- for( j=he.h_length; j; j-- ) {
- nextabyte[j-1] = atoi(next);
- while( *next!='.' && *next!=' ' && *next && *next!='\t' ) next++;
- if( *next ) next++;
- }
- if( *next=='.' ) next++;
- }
- *at = NULL;
- }
-
- next = malloc( c->len + he_size( ohe ) + 3 );
- memcpy( next, key, c->len );
- c->key = next;
- c->cont = he_copy( next + ((c->len+3)&~3), ohe );
- fgets( buffer, 255, f );
- }
- fclose(f);
- }
-
-
- void cache_print( void )
- {
- struct cache_s *c;
- int i, j;
- char buf[255];
- time_t t;
- unsigned char *addr;
-
- time( &t );
- for( c=cache,i=cachesize; i; i--,c++ ) if( c->key )
- {
- cwprintf(NULL, "type=" );
- switch( c->type )
- {
- case CACHE_NAME:
- case CACHE_MX:
- memcpy( buf, c->key, c->len );
- buf[c->len] = 0;
- cwprintf(NULL, "%s, name=%s", c->type==CACHE_NAME?"NAME":"MX", buf );
- break;
- case CACHE_ADDR:
- addr = (unsigned char *)c->key;
- cwprintf(NULL, "ADDR, address=%d", addr[c->len-1]);
- for (j = c->len-2; j >= 0; j--)
- cwprintf(NULL, ".%d", addr[j]);
- break;
- default:
- cwprintf(NULL, "unknown" );
- }
- if( difftime( t, c->expires ) >= 0 )
- cwprintf(NULL, ", expired since" );
- else
- cwprintf(NULL, ", expires at" );
- strftime( buf, 255, "%H:%M:%S on %a, %d %b %Y", localtime( &c->expires ) );
- cwprintf( NULL, " %s\n", buf );
- }
- }
-
-
- void cache_purge( void )
- {
- int i;
-
- for( i=0; i<cachesize; i++ )
- kill_cache( &cache[i] );
- }
-
- void cache_init( unsigned int size )
- {
- cachesize = size;
- cache = malloc(cachesize * sizeof(struct cache_s));
-
- memset(cache, 0, cachesize * sizeof(struct cache_s));
-
- cache_restore();
- atexit(cache_save);
- }
-