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