[icmp-dn.git] / nss-icmp.c

/*
 *  nss-icmp or libnss_icmp - GNU C Library NSS module to query host
 *  names by ICMP.
 *  Copyright (C) 2005 Fredrik Tolf <fredrik@dolda2000.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 *  MA 02111-1307, USA
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <nss.h>
#include <sys/types.h>
#include <fcntl.h>

#define CONFIGFILE "/etc/nss-icmp.conf"
#if 0
#define DEBUGP(format...) fprintf(stderr, "nss-icmp: " format);
#else
#define DEBUGP(format...)
#endif

struct cache {
    struct cache *next, *prev;
    char *addr;
    socklen_t addrlen;
    int af;
    int notfound;
    char **names;
    time_t at, ttl;
};

static int inited = 0;
static int timeout = -1;
static int usecache = 1;
static time_t nfttl = 300;
static struct cache *cache = NULL;

static void readconfig(void)
{
    FILE *f;
    char linebuf[1024];
    char *p, *p2;
    
    if((f = fopen(CONFIGFILE, "r")) == NULL)
	return;
    
    while(fgets(linebuf, sizeof(linebuf), f) != NULL) {
	if(linebuf[0] == '#')
	    continue;
	if((p = strchr(linebuf, '\n')) != NULL)
	    *p = 0;
	if((p = strchr(linebuf, ' ')) != NULL) {
	    p2 = p + 1;
	    *p = 0;
	}
	if(!strcmp(linebuf, "timeout")) {
	    if(p2 == NULL)
		continue;
	    timeout = atoi(p2);
	}
	if(!strcmp(linebuf, "ttlnotfound")) {
	    if(p2 == NULL)
		continue;
	    nfttl = atoi(p2);
	}
	if(!strcmp(linebuf, "nocache")) {
	    usecache = 0;
	}
    }
    
    fclose(f);
}

static void freecache(struct cache *cc)
{
    int i;
    
    if(cc->next != NULL)
	cc->next->prev = cc->prev;
    if(cc->prev != NULL)
	cc->prev->next = cc->next;
    if(cc == cache)
	cache = cc->next;
    if(cc->addr != NULL)
	free(cc->addr);
    if(cc->names != NULL) {
	for(i = 0; cc->names[i] != NULL; i++)
	    free(cc->names[i]);
	free(cc->names);
    }
    free(cc);
}

static void cachenotfound(const void *addr, socklen_t len, int af, time_t ttl)
{
    struct cache *cc;
    
    for(cc = cache; cc != NULL; cc = cc->next) {
	if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
	    break;
    }
    if(cc == NULL) {
	if((cc = malloc(sizeof(*cc))) == NULL)
	    return;
	memset(cc, 0, sizeof(*cc));
	if((cc->addr = malloc(len)) == NULL) {
	    freecache(cc);
	    return;
	}
	memcpy(cc->addr, addr, len);
	cc->addrlen = len;
	cc->af = af;
	cc->at = time(NULL);
	cc->ttl = ttl;
	
	cc->notfound = 1;
	
	cc->next = cache;
	if(cache != NULL)
	    cache->prev = cc;
	cache = cc;
    }
}

static void updatecache(const void *addr, socklen_t len, int af, char **names, time_t ttl)
{
    int i;
    struct cache *cc;
    
    for(cc = cache; cc != NULL; cc = cc->next) {
	if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
	    break;
    }
    if(cc == NULL) {
	if((cc = malloc(sizeof(*cc))) == NULL)
	    return;
	memset(cc, 0, sizeof(*cc));
	if((cc->addr = malloc(len)) == NULL) {
	    freecache(cc);
	    return;
	}
	memcpy(cc->addr, addr, len);
	cc->addrlen = len;
	cc->af = af;
	cc->at = time(NULL);
	cc->ttl = ttl;
	
	for(i = 0; names[i] != NULL; i++);
	if((cc->names = malloc(sizeof(*(cc->names)) * (i + 1))) == NULL) {
	    freecache(cc);
	    return;
	}
	memset(cc->names, 0, sizeof(*(cc->names)) * (i + 1));
	for(i = 0; names[i] != NULL; i++) {
	    if((cc->names[i] = malloc(strlen(names[i]) + 1)) == NULL) {
		freecache(cc);
		return;
	    }
	    strcpy(cc->names[i], names[i]);
	}
	
	cc->next = cache;
	if(cache != NULL)
	    cache->prev = cc;
	cache = cc;
    }
}

static void expirecache(void)
{
    struct cache *cc, *next;
    time_t now;
    
    now = time(NULL);
    for(cc = cache; cc != NULL; cc = next) {
	next = cc->next;
	if(now - cc->at > cc->ttl) {
	    freecache(cc);
	    continue;
	}
    }
}

enum nss_status _nss_icmp_gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop)
{
    int i, ret;
    struct retstruct {
	char *aliaslist[16];
	char *addrlist[2];
	char retaddr[16];
    } *retbuf;
    char addrbuf[1024];
    int an, thislen, ttl;
    char *p, *p2, *p3;
    u_int8_t *ap;
    pid_t child;
    int pfd[2];
    int rl;
    struct cache *cc;
    
    if(!inited) {
	readconfig();
	inited = 1;
    }
    
    retbuf = (struct retstruct *)buffer;
    if((buflen < sizeof(*retbuf)) || (len > sizeof(retbuf->retaddr))) {
	*errnop = ENOMEM;
	*h_errnop = NETDB_INTERNAL;
	return(NSS_STATUS_UNAVAIL);
    }
    
    DEBUGP("starting lookup\n");
    
    if(usecache) {
	expirecache();
	for(cc = cache; cc != NULL; cc = cc->next) {
	    if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
		break;
	}
    } else {
	cc = NULL;
    }
    
    if(cc == NULL) {
	DEBUGP("address not in cache, looking up for real\n");
	ap = (u_int8_t *)addr;
	if(inet_ntop(af, addr, addrbuf, sizeof(addrbuf)) == NULL) {
	    *errnop = errno;
	    *h_errnop = NETDB_INTERNAL;
	    return(NSS_STATUS_UNAVAIL);
	}
	DEBUGP("address is %s\n", addrbuf);
    
	if(pipe(pfd)) {
	    *errnop = errno;
	    *h_errnop = NETDB_INTERNAL;
	    return(NSS_STATUS_UNAVAIL);
	}
	/* I honestly don't know if it is considered OK to fork in other
	 * people's programs. We need a SUID worker, though, so there's
	 * little choice that I can see. */
	if((child = fork()) < 0) {
	    *errnop = errno;
	    *h_errnop = NETDB_INTERNAL;
	    return(NSS_STATUS_UNAVAIL);
	}
    
	if(child == 0) {
	    int i, fd;
	    char timeoutbuf[128];
	
	    if((fd = open("/dev/null", O_WRONLY)) < 0)
		exit(127);
	    close(pfd[0]);
	    dup2(pfd[1], 1);
	    dup2(fd, 2);
	    for(i = 3; i < FD_SETSIZE; i++)
		close(i);
	
	    if(timeout != -1) {
		snprintf(timeoutbuf, sizeof(timeoutbuf), "%i", timeout);
		execlp("idnlookup", "idnlookup", "-Tt", timeoutbuf, addrbuf, NULL);
	    } else {
		execlp("idnlookup", "idnlookup", "-T", addrbuf, NULL);
	    }
	    exit(127);
	}
    
	close(pfd[1]);
    
	rl = 0;
	do {
	    ret = read(pfd[0], addrbuf + rl, sizeof(addrbuf) - rl);
	    if(ret < 0) {
		*errnop = errno;
		*h_errnop = NETDB_INTERNAL;
		close(pfd[0]);
		return(NSS_STATUS_UNAVAIL);
	    }
	    rl += ret;
	    if(rl >= sizeof(addrbuf) - 1) {
		*errnop = ENOMEM;
		*h_errnop = NETDB_INTERNAL;
		close(pfd[0]);
		return(NSS_STATUS_UNAVAIL);
	    }
	} while(ret != 0);
	addrbuf[rl] = 0;
	close(pfd[0]);
	
	if((p = strchr(addrbuf, '\n')) == NULL) {
	    if(usecache)
		cachenotfound(addr, len, af, nfttl);
	    *h_errnop = TRY_AGAIN; /* XXX: Is this correct? */
	    return(NSS_STATUS_NOTFOUND);
	}
	*(p++) = 0;
	ttl = atoi(addrbuf);
	
	an = 0;
	p3 = buffer + sizeof(*retbuf);
	while((p2 = strchr(p, '\n')) != NULL) {
	    *p2 = 0;
	    thislen = p2 - p;
	    if(thislen == 0)
		continue;
	    if((p3 - buffer) + thislen + 1 > buflen) {
		*errnop = ENOMEM;
		*h_errnop = NETDB_INTERNAL;
		return(NSS_STATUS_UNAVAIL);
	    }
	    memcpy(p3, p, thislen + 1);
	    retbuf->aliaslist[an] = p3;
	    p3 += thislen + 1;
	    p = p2 + 1;
	    if(++an == 16) {
		*errnop = ENOMEM;
		*h_errnop = NETDB_INTERNAL;
		return(NSS_STATUS_UNAVAIL);
	    }
	}
	if(an == 0) {
	    if(usecache)
		cachenotfound(addr, len, af, nfttl);
	    *h_errnop = TRY_AGAIN; /* XXX: Is this correct? */
	    return(NSS_STATUS_NOTFOUND);
	}
	retbuf->aliaslist[an] = NULL;
	
	if(usecache)
	    updatecache(addr, len, af, retbuf->aliaslist, ttl);
    } else {
	DEBUGP("address found in cache\n");
	if(cc->notfound) {
	    *h_errnop = TRY_AGAIN; /* XXX: Is this correct? */
	    return(NSS_STATUS_NOTFOUND);
	}
	
	p3 = buffer + sizeof(*retbuf);
	for(i = 0; cc->names[i] != NULL; i++) {
	    thislen = strlen(cc->names[i]);
	    DEBUGP("filling in address %s, length %i\n", cc->names[i], thislen);
	    if((p3 - buffer) + thislen + 1 > buflen) {
		*errnop = ENOMEM;
		*h_errnop = NETDB_INTERNAL;
		return(NSS_STATUS_UNAVAIL);
	    }
	    memcpy(p3, cc->names[i], thislen + 1);
	    retbuf->aliaslist[i] = p3;
	    p3 += thislen + 1;
	}
	retbuf->aliaslist[i] = NULL;
    }
    
    DEBUGP("returning hostent\n");
    memcpy(retbuf->retaddr, addr, len);
    retbuf->addrlist[0] = retbuf->retaddr;
    retbuf->addrlist[1] = NULL;
    result->h_name = retbuf->aliaslist[0];
    result->h_aliases = retbuf->aliaslist;
    result->h_addr_list = retbuf->addrlist;
    result->h_addrtype = af;
    result->h_length = len;
    
    *h_errnop = NETDB_SUCCESS;
    DEBUGP("returning\n");
    return(NSS_STATUS_SUCCESS);
}

/*
 * Local Variables:
 * compile-command: "gcc -shared -Wall -g -o libnss_icmp.so.2 nss-icmp.c"
 * End:
 */
Commit	Line	Data
732b8359 DC	1	/*
	2	* nss-icmp or libnss_icmp - GNU C Library NSS module to query host
	3	* names by ICMP.
	4	* Copyright (C) 2005 Fredrik Tolf <fredrik@dolda2000.com>
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Library General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Library General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Library General Public
	17	* License along with this library; if not, write to the Free
	18	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	19	* MA 02111-1307, USA
	20	*/
	21
2dec74ab DC	22	#include <stdlib.h>
	23	#include <stdio.h>
	24	#include <unistd.h>
	25	#include <string.h>
	26	#include <errno.h>
f0df8f66	27	#include <time.h>
2dec74ab DC	28	#include <sys/socket.h>
	29	#include <netinet/in.h>
	30	#include <netdb.h>
	31	#include <arpa/inet.h>
	32	#include <nss.h>
	33	#include <sys/types.h>
	34	#include <fcntl.h>
	35
15a913c2	36	#define CONFIGFILE "/etc/nss-icmp.conf"
78d913fb DC	37	#if 0
	38	#define DEBUGP(format...) fprintf(stderr, "nss-icmp: " format);
	39	#else
	40	#define DEBUGP(format...)
	41	#endif
15a913c2 DC	42
	43	struct cache {
	44	struct cache next, prev;
	45	char *addr;
	46	socklen_t addrlen;
	47	int af;
	48	int notfound;
	49	char **names;
f0df8f66	50	time_t at, ttl;
15a913c2 DC	51	};
	52
	53	static int inited = 0;
	54	static int timeout = -1;
	55	static int usecache = 1;
f0df8f66	56	static time_t nfttl = 300;
15a913c2 DC	57	static struct cache *cache = NULL;
	58
	59	static void readconfig(void)
	60	{
	61	FILE *f;
	62	char linebuf[1024];
	63	char p, p2;
	64
	65	if((f = fopen(CONFIGFILE, "r")) == NULL)
	66	return;
	67
	68	while(fgets(linebuf, sizeof(linebuf), f) != NULL) {
	69	if(linebuf[0] == '#')
	70	continue;
	71	if((p = strchr(linebuf, '\n')) != NULL)
	72	*p = 0;
	73	if((p = strchr(linebuf, ' ')) != NULL) {
	74	p2 = p + 1;
	75	*p = 0;
	76	}
	77	if(!strcmp(linebuf, "timeout")) {
	78	if(p2 == NULL)
	79	continue;
	80	timeout = atoi(p2);
	81	}
f0df8f66 DC	82	if(!strcmp(linebuf, "ttlnotfound")) {
	83	if(p2 == NULL)
	84	continue;
	85	nfttl = atoi(p2);
	86	}
15a913c2 DC	87	if(!strcmp(linebuf, "nocache")) {
	88	usecache = 0;
	89	}
	90	}
	91
	92	fclose(f);
	93	}
	94
	95	static void freecache(struct cache *cc)
	96	{
	97	int i;
	98
	99	if(cc->next != NULL)
	100	cc->next->prev = cc->prev;
	101	if(cc->prev != NULL)
	102	cc->prev->next = cc->next;
	103	if(cc == cache)
	104	cache = cc->next;
	105	if(cc->addr != NULL)
	106	free(cc->addr);
	107	if(cc->names != NULL) {
	108	for(i = 0; cc->names[i] != NULL; i++)
	109	free(cc->names[i]);
	110	free(cc->names);
	111	}
	112	free(cc);
	113	}
	114
f0df8f66	115	static void cachenotfound(const void *addr, socklen_t len, int af, time_t ttl)
15a913c2 DC	116	{
	117	struct cache *cc;
	118
	119	for(cc = cache; cc != NULL; cc = cc->next) {
	120	if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
	121	break;
	122	}
	123	if(cc == NULL) {
	124	if((cc = malloc(sizeof(*cc))) == NULL)
	125	return;
	126	memset(cc, 0, sizeof(*cc));
	127	if((cc->addr = malloc(len)) == NULL) {
	128	freecache(cc);
	129	return;
	130	}
	131	memcpy(cc->addr, addr, len);
	132	cc->addrlen = len;
	133	cc->af = af;
f0df8f66 DC	134	cc->at = time(NULL);
f0df8f66 DC	135	cc->ttl = ttl;
15a913c2 DC	136
	137	cc->notfound = 1;
	138
	139	cc->next = cache;
	140	if(cache != NULL)
	141	cache->prev = cc;
	142	cache = cc;
	143	}
	144	}
	145
f0df8f66	146	static void updatecache(const void addr, socklen_t len, int af, char *names, time_t ttl)
15a913c2 DC	147	{
	148	int i;
	149	struct cache *cc;
	150
	151	for(cc = cache; cc != NULL; cc = cc->next) {
f0df8f66	152	if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
15a913c2 DC	153	break;
	154	}
	155	if(cc == NULL) {
	156	if((cc = malloc(sizeof(*cc))) == NULL)
	157	return;
	158	memset(cc, 0, sizeof(*cc));
f0df8f66	159	if((cc->addr = malloc(len)) == NULL) {
15a913c2 DC	160	freecache(cc);
	161	return;
	162	}
f0df8f66 DC	163	memcpy(cc->addr, addr, len);
	164	cc->addrlen = len;
	165	cc->af = af;
	166	cc->at = time(NULL);
	167	cc->ttl = ttl;
15a913c2	168
f0df8f66	169	for(i = 0; names[i] != NULL; i++);
15a913c2 DC	170	if((cc->names = malloc(sizeof((cc->names)) (i + 1))) == NULL) {
	171	freecache(cc);
	172	return;
	173	}
	174	memset(cc->names, 0, sizeof((cc->names)) (i + 1));
f0df8f66 DC	175	for(i = 0; names[i] != NULL; i++) {
f0df8f66 DC	176	if((cc->names[i] = malloc(strlen(names[i]) + 1)) == NULL) {
15a913c2 DC	177	freecache(cc);
	178	return;
	179	}
f0df8f66	180	strcpy(cc->names[i], names[i]);
15a913c2 DC	181	}
	182
	183	cc->next = cache;
	184	if(cache != NULL)
	185	cache->prev = cc;
	186	cache = cc;
	187	}
	188	}
	189
f0df8f66 DC	190	static void expirecache(void)
	191	{
	192	struct cache cc, next;
	193	time_t now;
	194
	195	now = time(NULL);
	196	for(cc = cache; cc != NULL; cc = next) {
	197	next = cc->next;
	198	if(now - cc->at > cc->ttl) {
	199	freecache(cc);
	200	continue;
	201	}
	202	}
	203	}
	204
2dec74ab DC	205	enum nss_status _nss_icmp_gethostbyaddr_r(const void addr, socklen_t len, int af, struct hostent result, char buffer, size_t buflen, int errnop, int *h_errnop)
2dec74ab DC	206	{
15a913c2	207	int i, ret;
2dec74ab DC	208	struct retstruct {
	209	char *aliaslist[16];
	210	char *addrlist[2];
	211	char retaddr[16];
	212	} *retbuf;
	213	char addrbuf[1024];
f0df8f66	214	int an, thislen, ttl;
2dec74ab DC	215	char p, p2, *p3;
	216	u_int8_t *ap;
	217	pid_t child;
	218	int pfd[2];
	219	int rl;
15a913c2 DC	220	struct cache *cc;
	221
	222	if(!inited) {
	223	readconfig();
	224	inited = 1;
	225	}
2dec74ab DC	226
	227	retbuf = (struct retstruct *)buffer;
	228	if((buflen < sizeof(*retbuf)) \|\| (len > sizeof(retbuf->retaddr))) {
	229	*errnop = ENOMEM;
	230	*h_errnop = NETDB_INTERNAL;
	231	return(NSS_STATUS_UNAVAIL);
	232	}
	233
78d913fb DC	234	DEBUGP("starting lookup\n");
78d913fb DC	235
f416a8cd	236	if(usecache) {
f0df8f66	237	expirecache();
f416a8cd DC	238	for(cc = cache; cc != NULL; cc = cc->next) {
	239	if((cc->af == af) && (cc->addrlen == len) && !memcmp(cc->addr, addr, len))
	240	break;
	241	}
	242	} else {
	243	cc = NULL;
2dec74ab DC	244	}
2dec74ab DC	245
15a913c2	246	if(cc == NULL) {
78d913fb	247	DEBUGP("address not in cache, looking up for real\n");
15a913c2 DC	248	ap = (u_int8_t *)addr;
15a913c2 DC	249	if(inet_ntop(af, addr, addrbuf, sizeof(addrbuf)) == NULL) {
2dec74ab DC	250	*errnop = errno;
2dec74ab DC	251	*h_errnop = NETDB_INTERNAL;
2dec74ab DC	252	return(NSS_STATUS_UNAVAIL);
2dec74ab DC	253	}
78d913fb	254	DEBUGP("address is %s\n", addrbuf);
15a913c2 DC	255
	256	if(pipe(pfd)) {
	257	*errnop = errno;
2dec74ab	258	*h_errnop = NETDB_INTERNAL;
2dec74ab DC	259	return(NSS_STATUS_UNAVAIL);
2dec74ab DC	260	}
15a913c2 DC	261	/* I honestly don't know if it is considered OK to fork in other
	262	* people's programs. We need a SUID worker, though, so there's
	263	* little choice that I can see. */
	264	if((child = fork()) < 0) {
	265	*errnop = errno;
2dec74ab DC	266	*h_errnop = NETDB_INTERNAL;
	267	return(NSS_STATUS_UNAVAIL);
	268	}
15a913c2 DC	269
	270	if(child == 0) {
	271	int i, fd;
	272	char timeoutbuf[128];
	273
	274	if((fd = open("/dev/null", O_WRONLY)) < 0)
	275	exit(127);
	276	close(pfd[0]);
	277	dup2(pfd[1], 1);
	278	dup2(fd, 2);
	279	for(i = 3; i < FD_SETSIZE; i++)
	280	close(i);
	281
	282	if(timeout != -1) {
	283	snprintf(timeoutbuf, sizeof(timeoutbuf), "%i", timeout);
f0df8f66	284	execlp("idnlookup", "idnlookup", "-Tt", timeoutbuf, addrbuf, NULL);
15a913c2	285	} else {
f0df8f66	286	execlp("idnlookup", "idnlookup", "-T", addrbuf, NULL);
15a913c2 DC	287	}
	288	exit(127);
	289	}
	290
	291	close(pfd[1]);
	292
	293	rl = 0;
	294	do {
	295	ret = read(pfd[0], addrbuf + rl, sizeof(addrbuf) - rl);
	296	if(ret < 0) {
	297	*errnop = errno;
	298	*h_errnop = NETDB_INTERNAL;
	299	close(pfd[0]);
	300	return(NSS_STATUS_UNAVAIL);
	301	}
	302	rl += ret;
	303	if(rl >= sizeof(addrbuf) - 1) {
	304	*errnop = ENOMEM;
	305	*h_errnop = NETDB_INTERNAL;
	306	close(pfd[0]);
	307	return(NSS_STATUS_UNAVAIL);
	308	}
	309	} while(ret != 0);
	310	addrbuf[rl] = 0;
	311	close(pfd[0]);
f0df8f66 DC	312
	313	if((p = strchr(addrbuf, '\n')) == NULL) {
	314	if(usecache)
	315	cachenotfound(addr, len, af, nfttl);
	316	h_errnop = TRY_AGAIN; / XXX: Is this correct? */
	317	return(NSS_STATUS_NOTFOUND);
	318	}
	319	*(p++) = 0;
	320	ttl = atoi(addrbuf);
	321
15a913c2	322	an = 0;
15a913c2 DC	323	p3 = buffer + sizeof(*retbuf);
	324	while((p2 = strchr(p, '\n')) != NULL) {
	325	*p2 = 0;
	326	thislen = p2 - p;
	327	if(thislen == 0)
	328	continue;
	329	if((p3 - buffer) + thislen + 1 > buflen) {
	330	*errnop = ENOMEM;
	331	*h_errnop = NETDB_INTERNAL;
	332	return(NSS_STATUS_UNAVAIL);
	333	}
	334	memcpy(p3, p, thislen + 1);
	335	retbuf->aliaslist[an] = p3;
	336	p3 += thislen + 1;
	337	p = p2 + 1;
	338	if(++an == 16) {
	339	*errnop = ENOMEM;
	340	*h_errnop = NETDB_INTERNAL;
	341	return(NSS_STATUS_UNAVAIL);
	342	}
	343	}
	344	if(an == 0) {
f416a8cd	345	if(usecache)
f0df8f66	346	cachenotfound(addr, len, af, nfttl);
15a913c2 DC	347	h_errnop = TRY_AGAIN; / XXX: Is this correct? */
	348	return(NSS_STATUS_NOTFOUND);
	349	}
	350	retbuf->aliaslist[an] = NULL;
f0df8f66 DC	351
	352	if(usecache)
	353	updatecache(addr, len, af, retbuf->aliaslist, ttl);
15a913c2	354	} else {
78d913fb	355	DEBUGP("address found in cache\n");
15a913c2 DC	356	if(cc->notfound) {
	357	h_errnop = TRY_AGAIN; / XXX: Is this correct? */
	358	return(NSS_STATUS_NOTFOUND);
	359	}
	360
	361	p3 = buffer + sizeof(*retbuf);
	362	for(i = 0; cc->names[i] != NULL; i++) {
	363	thislen = strlen(cc->names[i]);
78d913fb	364	DEBUGP("filling in address %s, length %i\n", cc->names[i], thislen);
15a913c2 DC	365	if((p3 - buffer) + thislen + 1 > buflen) {
	366	*errnop = ENOMEM;
	367	*h_errnop = NETDB_INTERNAL;
	368	return(NSS_STATUS_UNAVAIL);
	369	}
	370	memcpy(p3, cc->names[i], thislen + 1);
78d913fb	371	retbuf->aliaslist[i] = p3;
15a913c2	372	p3 += thislen + 1;
2dec74ab	373	}
78d913fb	374	retbuf->aliaslist[i] = NULL;
2dec74ab	375	}
2dec74ab	376
78d913fb	377	DEBUGP("returning hostent\n");
2dec74ab DC	378	memcpy(retbuf->retaddr, addr, len);
	379	retbuf->addrlist[0] = retbuf->retaddr;
	380	retbuf->addrlist[1] = NULL;
	381	result->h_name = retbuf->aliaslist[0];
	382	result->h_aliases = retbuf->aliaslist;
	383	result->h_addr_list = retbuf->addrlist;
	384	result->h_addrtype = af;
	385	result->h_length = len;
	386
	387	*h_errnop = NETDB_SUCCESS;
78d913fb	388	DEBUGP("returning\n");
2dec74ab DC	389	return(NSS_STATUS_SUCCESS);
2dec74ab DC	390	}
732b8359 DC	391
	392	/*
	393	* Local Variables:
	394	* compile-command: "gcc -shared -Wall -g -o libnss_icmp.so.2 nss-icmp.c"
	395	* End:
	396	*/