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