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03b6b479 | 1 | |
908a6ebe | 2 | /***************************************************************************** |
3 | * libnss-afs (nss_afs.c) | |
03b6b479 | 4 | * |
5 | * Copyright 2008, licensed under GNU Library General Public License (LGPL) | |
6 | * see COPYING file for details | |
7 | * | |
908a6ebe | 8 | * by Adam Megacz <megacz@hcoop.net> |
03b6b479 | 9 | * derived from Frank Burkhardt's libnss_ptdb, |
10 | * which was derived from Todd M. Lewis' libnss_pts | |
908a6ebe | 11 | *****************************************************************************/ |
03b6b479 | 12 | |
13 | /* | |
908a6ebe | 14 | * If you are reading this code for the first time, read the rest of |
15 | * this comment block, then start at the bottom of the file and work | |
16 | * your way upwards. | |
17 | * | |
18 | * All functions which return an int use zero to signal success -- | |
19 | * except cpstr(), which returns zero on *failure*. This should be | |
20 | * fixed. | |
21 | * | |
22 | * A note about memory allocation: | |
23 | * | |
24 | * NSS plugins generally ought to work without attempting to call | |
25 | * malloc() (which may fail). Therefore, glibc allocates a buffer | |
26 | * before calling NSS library functions, and passes that buffer to | |
27 | * the NSS library; library functions store their results in the | |
28 | * buffer and return pointers into that buffer. | |
29 | * | |
30 | * The convention used throughout this library is to pass around a | |
31 | * char** which points to a pointer to the first unused byte in the | |
32 | * provided buffer, and a size_t* which points to an int indicating | |
33 | * how many bytes are left between the char** and the end of the | |
34 | * available region. | |
03b6b479 | 35 | */ |
36 | ||
37 | #include <ctype.h> | |
38 | #include <err.h> | |
39 | #include <errno.h> | |
40 | #include <fcntl.h> | |
41 | #include <getopt.h> | |
42 | #include <grp.h> | |
43 | #include <netinet/in.h> | |
44 | #include <nss.h> | |
45 | #include <pthread.h> | |
46 | #include <pwd.h> | |
47 | #include <rx/rx.h> | |
48 | #include <rx/xdr.h> | |
49 | #include <signal.h> | |
50 | #include <stdio.h> | |
51 | #include <stdlib.h> | |
52 | #include <string.h> | |
53 | #include <sys/select.h> | |
54 | #include <sys/socket.h> | |
43d1801e | 55 | #include <sys/stat.h> |
03b6b479 | 56 | #include <sys/time.h> |
57 | #include <sys/types.h> | |
58 | #include <unistd.h> | |
03b6b479 | 59 | #include <afs/afsutil.h> |
60 | #include <afs/cellconfig.h> | |
61 | #include <afs/com_err.h> | |
62 | #include <afs/param.h> | |
63 | #include <afs/ptclient.h> | |
64 | #include <afs/pterror.h> | |
2cc65a80 | 65 | #include <afs/ptuser.h> |
03b6b479 | 66 | #include <afs/stds.h> |
67 | ||
908a6ebe | 68 | #define HOMEDIR_AUTO 0 |
03b6b479 | 69 | #define HOMEDIR_ADMINLINK 1 |
908a6ebe | 70 | #define HOMEDIR_PREFIX 2 |
71 | #define SHELL_BASH 0 | |
72 | #define SHELL_ADMINLINK 1 | |
73 | #define SHELL_USERLINK 2 | |
03b6b479 | 74 | |
75 | #define AFS_MAGIC_ANONYMOUS_USERID 32766 | |
908a6ebe | 76 | #define MIN_PAG_GID 0x41000000L |
77 | #define MAX_PAG_GID 0x41FFFFFFL | |
78 | #define MIN_OLDPAG_GID 0x3f00 | |
79 | #define MAX_OLDPAG_GID 0xff00 | |
03b6b479 | 80 | |
908a6ebe | 81 | #define MAXCELLNAMELEN 256 |
abfd757b | 82 | #define MAXUSERNAMELEN 256 |
91bb9ebc | 83 | |
03b6b479 | 84 | static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; |
85 | ||
03b6b479 | 86 | extern struct ubik_client *pruclient; |
87 | ||
88 | int afs_initialized = 0; | |
908a6ebe | 89 | char cellname[MAXCELLNAMELEN]; |
90 | char homedir_prefix[MAXPATHLEN]; | |
43d1801e | 91 | char cell_root[MAXPATHLEN]; |
03b6b479 | 92 | int homedir_prefix_len=0; |
93 | char homedirs_method=0; | |
94 | char shells_method=0; | |
95 | ||
2cc65a80 CE |
96 | int init_afs (); |
97 | ||
908a6ebe | 98 | /** |
99 | * The cpstr() function copies a null-terminated string from str* | |
100 | * (the first argument) into buf and updates both buf and buflen. If | |
101 | * the string would overflow the buffer, no action is taken. The | |
102 | * number of bytes copied is returned (zero indicates failure). | |
103 | */ | |
03b6b479 | 104 | int cpstr( char *str, char **buf, size_t *buflen) { |
908a6ebe | 105 | int len = strlen(str); |
106 | if ( len >= *buflen-1 ) return 0; | |
107 | strcpy(*buf,str); | |
108 | *buflen -= len + 1; | |
109 | *buf += len + 1; | |
110 | return len; | |
03b6b479 | 111 | } |
112 | ||
908a6ebe | 113 | /** |
03b6b479 | 114 | * Look up the name corresponding to uid, store in buffer. |
03b6b479 | 115 | */ |
0fa533e2 | 116 | enum nss_status ptsid2name(int uid, char **buffer, size_t *buflen) { |
03b6b479 | 117 | int ret, i; |
118 | idlist lid; | |
119 | namelist lnames; | |
120 | ||
b5f46b9e | 121 | if (init_afs()) return NSS_STATUS_UNAVAIL; |
03b6b479 | 122 | |
123 | if (uid==AFS_MAGIC_ANONYMOUS_USERID) { | |
124 | if (!cpstr("anonymous", buffer, buflen)) return NSS_STATUS_UNAVAIL; | |
125 | return NSS_STATUS_SUCCESS; | |
126 | } | |
127 | ||
128 | if (pthread_mutex_lock(&mutex)) return NSS_STATUS_UNAVAIL; | |
129 | ||
130 | lid.idlist_val = (afs_int32*)&uid; | |
131 | lid.idlist_len = 1; | |
132 | lnames.namelist_val = 0; | |
133 | lnames.namelist_len = 0; | |
134 | ||
2cc65a80 | 135 | if (ubik_PR_IDToName(pruclient,0,&lid,&lnames) != PRSUCCESS) { |
be93aa7b | 136 | perror("ubik_Call() in ptsid2name() failed\n"); |
03b6b479 | 137 | pthread_mutex_unlock(&mutex); |
138 | return NSS_STATUS_UNAVAIL; | |
139 | } | |
140 | ||
141 | ret = NSS_STATUS_NOTFOUND; | |
142 | for (i=0;i<lnames.namelist_len;i++) { | |
143 | int delta = strlen(lnames.namelist_val[i]); | |
5fea146a | 144 | if ( (delta < *buflen) && islower(*(lnames.namelist_val[i])) ) { |
03b6b479 | 145 | cpstr(lnames.namelist_val[i], buffer, buflen); |
146 | ret = NSS_STATUS_SUCCESS; | |
147 | } | |
148 | } | |
149 | free(lnames.namelist_val); | |
150 | /* free(lid.idlist_val); */ | |
151 | lid.idlist_val = 0; | |
152 | lid.idlist_len = 0; | |
153 | ||
154 | pthread_mutex_unlock(&mutex); | |
155 | return ret; | |
156 | } | |
157 | ||
908a6ebe | 158 | /** |
159 | * Look up the uid corresponding to name in ptserver. | |
03b6b479 | 160 | */ |
908a6ebe | 161 | enum nss_status ptsname2id(char *name, uid_t* uid) { |
03b6b479 | 162 | int res; |
163 | idlist lid; | |
164 | namelist lnames; | |
abfd757b | 165 | char uname[MAXUSERNAMELEN]; |
03b6b479 | 166 | |
b5f46b9e | 167 | if (init_afs()) return NSS_STATUS_UNAVAIL; |
03b6b479 | 168 | |
169 | if (!strcmp(name,"anonymous")) { | |
170 | *uid = AFS_MAGIC_ANONYMOUS_USERID; | |
171 | return NSS_STATUS_SUCCESS; | |
172 | } | |
173 | ||
174 | if (pthread_mutex_lock(&mutex)) return NSS_STATUS_UNAVAIL; | |
175 | ||
176 | lid.idlist_val = 0; | |
177 | lid.idlist_len = 0; | |
be93aa7b | 178 | lnames.namelist_val = (prname*)uname; |
abfd757b | 179 | // apparently ubik expects to be able to modify this? |
180 | strncpy(uname, name, MAXUSERNAMELEN); | |
03b6b479 | 181 | lnames.namelist_len = 1; |
182 | ||
2cc65a80 | 183 | if (ubik_PR_NameToID(pruclient,0,&lnames,&lid) != PRSUCCESS) { |
be93aa7b | 184 | perror("ubik_Call() in ptsname2id() failed\n"); |
03b6b479 | 185 | pthread_mutex_unlock(&mutex); |
186 | return NSS_STATUS_UNAVAIL; | |
187 | } | |
188 | pthread_mutex_unlock(&mutex); | |
189 | ||
190 | res = (uid_t)lid.idlist_val[0]; | |
191 | if (res == AFS_MAGIC_ANONYMOUS_USERID) return NSS_STATUS_NOTFOUND; | |
192 | *uid = res; | |
193 | return NSS_STATUS_SUCCESS; | |
194 | } | |
195 | ||
908a6ebe | 196 | /** |
197 | * Initialize the library; returns zero on success | |
03b6b479 | 198 | */ |
199 | int init_afs() { | |
200 | FILE *thiscell; | |
201 | int len; | |
43d1801e | 202 | struct stat statbuf; |
03b6b479 | 203 | |
b5f46b9e AM |
204 | char buf[6]; |
205 | int fd; | |
206 | int pos; | |
207 | ||
43d1801e | 208 | if (afs_initialized) { |
209 | /* wait until /afs/@cell/ appears as a proxy for "the network is up" */ | |
210 | if (stat(cell_root, &statbuf)) return -1; | |
211 | return 0; | |
212 | } | |
b5f46b9e AM |
213 | |
214 | // check to make sure that we are running inside nscd | |
215 | pos = 0; | |
216 | fd = open("/proc/self/cmdline", O_RDONLY); | |
217 | if (fd==-1) return -1; | |
218 | while(1) { | |
219 | int numread; | |
220 | numread = read(fd, buf+pos, 1); | |
221 | if (buf[ (pos+5)%6 ] == 'd' && | |
222 | buf[ (pos+4)%6 ] == 'c' && | |
223 | buf[ (pos+3)%6 ] == 's' && | |
224 | buf[ (pos+2)%6 ] == 'n' && | |
225 | (buf[(pos+1)%6 ] == '/' || pos==4) && | |
226 | (buf[(pos+0)%6 ] == 0 || numread==-1) | |
227 | ) | |
228 | break; | |
229 | pos = (pos+1)%6; | |
230 | if (numread==0) { close(fd); return -1; } | |
231 | } | |
232 | close(fd); | |
43d1801e | 233 | |
03b6b479 | 234 | if (pthread_mutex_lock(&mutex)) return -1; |
235 | do { | |
236 | homedirs_method=HOMEDIR_PREFIX; | |
237 | shells_method=SHELL_USERLINK; | |
91bb9ebc | 238 | |
908a6ebe | 239 | len = snprintf(cellname, MAXCELLNAMELEN, |
240 | "%s/ThisCell", AFSDIR_CLIENT_ETC_DIRPATH); | |
be93aa7b | 241 | if (len < 0 || len >= MAXCELLNAMELEN) return -1; |
91bb9ebc | 242 | |
243 | thiscell=fopen(cellname,"r"); | |
03b6b479 | 244 | if (thiscell == NULL) break; |
908a6ebe | 245 | len=fread(cellname,1,MAXCELLNAMELEN,thiscell); |
03b6b479 | 246 | if (!feof(thiscell)) { |
247 | // Cellname too long | |
248 | fclose(thiscell); | |
249 | strcpy(homedir_prefix,"/tmp/\0"); | |
250 | homedir_prefix_len=5; | |
251 | break; | |
252 | } | |
253 | fclose(thiscell); | |
91bb9ebc | 254 | |
03b6b479 | 255 | if (cellname[len-1] == '\n') len--; |
256 | cellname[len]='\0'; | |
43d1801e | 257 | |
258 | /* wait until /afs/@cell/ appears as a proxy for "the network is up" */ | |
259 | sprintf(cell_root,"/afs/%s/",cellname); | |
260 | if (stat(cell_root, &statbuf)) break; | |
261 | ||
03b6b479 | 262 | sprintf(homedir_prefix,"/afs/%s/user/",cellname); |
263 | homedir_prefix_len=strlen(homedir_prefix); | |
43d1801e | 264 | |
265 | /* time out requests after 5 seconds to avoid hanging things */ | |
266 | rx_SetRxDeadTime(5); | |
267 | ||
93d939f4 | 268 | if (pr_Initialize(0L,AFSDIR_CLIENT_ETC_DIRPATH, 0)) { |
be93aa7b | 269 | perror("pr_Initialize() failed\n"); |
93d939f4 | 270 | break; |
271 | } | |
03b6b479 | 272 | |
273 | afs_initialized = 1; | |
274 | pthread_mutex_unlock(&mutex); | |
275 | return 0; | |
276 | ||
277 | } while(0); | |
278 | pthread_mutex_unlock(&mutex); | |
279 | return -1; | |
280 | } | |
281 | ||
282 | ||
908a6ebe | 283 | /** |
284 | * Retrieves the homedir for a given user; returns 0 on success. | |
285 | */ | |
03b6b479 | 286 | int get_homedir(char *name, char **buffer, size_t *buflen) { |
287 | char buf[256]; | |
288 | int temp; | |
289 | char *b; | |
290 | b=*buffer; | |
291 | switch (homedirs_method) { | |
292 | case HOMEDIR_PREFIX: | |
293 | homedir_prefix[homedir_prefix_len+0]=name[0]; | |
294 | homedir_prefix[homedir_prefix_len+1]='/'; | |
295 | homedir_prefix[homedir_prefix_len+2]=name[0]; | |
296 | homedir_prefix[homedir_prefix_len+3]=name[1]; | |
297 | homedir_prefix[homedir_prefix_len+4]='/'; | |
298 | homedir_prefix[homedir_prefix_len+5]=0; | |
299 | strncpy(&homedir_prefix[homedir_prefix_len+5],name,40); | |
300 | if (! cpstr(homedir_prefix,buffer,buflen) ) return -1; | |
301 | break; | |
302 | case HOMEDIR_AUTO: | |
303 | homedir_prefix[homedir_prefix_len]=0; | |
304 | strncpy(&homedir_prefix[homedir_prefix_len],name,40); | |
305 | if (! cpstr(homedir_prefix,buffer,buflen) ) return -1; | |
306 | break; | |
307 | case HOMEDIR_ADMINLINK: | |
308 | if ( snprintf(buf,256,"/afs/%s/admin/homedirs/%s",cellname,name) > 0 ) { | |
309 | temp=readlink(buf,*buffer,*buflen); | |
310 | if ( temp > -1) { | |
311 | b[temp]=0; | |
312 | *buflen = *buflen - temp - 1; | |
313 | return -1; | |
314 | } | |
315 | } | |
316 | if (! cpstr("/tmp",buffer,buflen) ) return -1; | |
317 | break; | |
318 | } | |
319 | return 0; | |
320 | } | |
321 | ||
908a6ebe | 322 | /** |
323 | * Retrieves the shell for a given user; returns 0 on success. | |
324 | */ | |
03b6b479 | 325 | int get_shell(char *name, char **buffer, size_t *buflen) { |
326 | char buf[256]; | |
327 | int temp; | |
328 | char *b; | |
329 | char* bufx = buf; | |
0fa533e2 | 330 | size_t bufxlen = 256; |
03b6b479 | 331 | b=*buffer; |
332 | ||
333 | switch (shells_method) { | |
334 | case SHELL_BASH: | |
03b6b479 | 335 | break; |
336 | ||
337 | case SHELL_ADMINLINK: | |
91bb9ebc | 338 | if (snprintf(buf,256,"/afs/%s/admin/shells/%s",cellname,name)<=0) break; |
339 | temp = readlink(buf,*buffer,*buflen); | |
340 | if (temp < 0) break; | |
341 | b[temp]=0; | |
342 | *buflen = *buflen - temp - 1; | |
343 | return 0; | |
03b6b479 | 344 | |
345 | case SHELL_USERLINK: | |
91bb9ebc | 346 | if (get_homedir(name, &bufx, &bufxlen)) break; |
347 | if (strncpy(buf+strlen(buf),"/.loginshell",bufxlen)<=0) break; | |
348 | temp = readlink(buf,*buffer,*buflen); | |
349 | if (temp < 0) break; | |
350 | b[temp]=0; | |
351 | *buflen = *buflen - temp - 1; | |
352 | return 0; | |
03b6b479 | 353 | } |
91bb9ebc | 354 | if (! cpstr("/bin/bash",buffer,buflen) ) |
355 | return -1; | |
03b6b479 | 356 | return 0; |
357 | } | |
358 | ||
359 | ||
908a6ebe | 360 | /* |
361 | * This function is exported; glibc will invoke it in order to find | |
362 | * the name and list of members of a group specified by a numerical | |
363 | * groupid. | |
03b6b479 | 364 | */ |
908a6ebe | 365 | enum nss_status _nss_afs_getgrgid_r (gid_t gid, |
366 | struct group *result, | |
367 | char *buffer, | |
368 | size_t buflen, | |
369 | int *errnop) { | |
03b6b479 | 370 | int length; |
582fb19e | 371 | int showgid = 0; |
372 | if (gid >= MIN_PAG_GID && gid <= MAX_PAG_GID) { | |
373 | showgid = gid-MIN_PAG_GID; | |
374 | } else if (gid >= MIN_OLDPAG_GID && gid <= MAX_OLDPAG_GID) { | |
375 | showgid = gid-MIN_OLDPAG_GID; | |
376 | } else { | |
03b6b479 | 377 | *errnop=ENOENT; |
378 | return NSS_STATUS_NOTFOUND; | |
379 | } | |
380 | do { | |
381 | result->gr_gid=gid; | |
382 | ||
383 | result->gr_name=buffer; | |
582fb19e | 384 | length=snprintf(buffer,buflen,"AfsPag-%x",showgid); |
03b6b479 | 385 | |
386 | if (length < 0) break; | |
387 | length += 1; | |
388 | buflen -= length; | |
389 | buffer += length; | |
390 | ||
391 | result->gr_passwd=buffer; | |
392 | ||
277abbf3 | 393 | if (!cpstr("z",&buffer,&buflen)) break; |
03b6b479 | 394 | |
395 | if (buflen < sizeof(char*)) break; | |
446846ba | 396 | result->gr_mem=&buffer; |
03b6b479 | 397 | result->gr_mem[0] = NULL; |
398 | ||
399 | *errnop=errno; | |
400 | return NSS_STATUS_SUCCESS; | |
401 | ||
402 | } while(0); | |
403 | *errnop=ENOENT; | |
404 | return NSS_STATUS_UNAVAIL; | |
405 | } | |
406 | ||
908a6ebe | 407 | /** |
408 | * A helper function to fill in the fields of "struct passwd"; used by | |
409 | * both _nss_afs_getpwuid_r() and _nss_afs_getpwnam_r(). | |
410 | */ | |
411 | enum nss_status fill_result_buf(uid_t uid, | |
412 | char* name, | |
413 | struct passwd *result_buf, | |
414 | char *buffer, | |
415 | size_t buflen, | |
416 | int *errnop) { | |
417 | result_buf->pw_name = name; | |
03b6b479 | 418 | do { |
277abbf3 | 419 | /* set the password to "z"; we can't use "x" because of pam_unix.so */ |
03b6b479 | 420 | result_buf->pw_passwd = buffer; |
277abbf3 | 421 | if ( ! cpstr("z",&buffer, &buflen) ) break; |
908a6ebe | 422 | |
03b6b479 | 423 | /* the uid and gid are both the uid passed in */ |
424 | result_buf->pw_uid = uid; | |
425 | result_buf->pw_gid = 65534; | |
908a6ebe | 426 | |
03b6b479 | 427 | /* make the gecos the same as the PTS name */ |
428 | result_buf->pw_gecos = buffer; | |
429 | if ( ! cpstr(result_buf->pw_name, &buffer, &buflen ) ) break; | |
430 | ||
431 | // Set the homedirectory | |
432 | result_buf->pw_dir = buffer; | |
433 | if ( get_homedir(result_buf->pw_name,&buffer,&buflen) ) break; | |
434 | ||
435 | // Set the login shell | |
436 | result_buf->pw_shell = buffer; | |
437 | if ( get_shell(result_buf->pw_name,&buffer,&buflen) ) break; | |
438 | ||
e8c23dae | 439 | #ifdef LIMIT_USERNAME_CHARS |
440 | if ( strlen(result_buf->pw_name) > LIMIT_USERNAME_CHARS ) { | |
441 | result_buf->pw_name[LIMIT_USERNAME_CHARS] = '\0'; | |
442 | buflen = buflen + ( buffer - &result_buf->pw_name[LIMIT_USERNAME_CHARS+1] ); | |
443 | buffer = &result_buf->pw_name[LIMIT_USERNAME_CHARS+1]; | |
444 | } | |
445 | #endif | |
446 | ||
03b6b479 | 447 | *errnop = errno; |
448 | return NSS_STATUS_SUCCESS; | |
449 | } while(0); | |
450 | ||
451 | *errnop = ERANGE; | |
452 | return NSS_STATUS_UNAVAIL; | |
453 | } | |
454 | ||
455 | ||
908a6ebe | 456 | /** |
457 | * This function is exported; glibc will invoke it in order to gather | |
458 | * the user information (userid, homedir, shell) associated with a | |
459 | * numerical userid. | |
460 | */ | |
461 | enum nss_status _nss_afs_getpwuid_r (uid_t uid, | |
462 | struct passwd *result_buf, | |
463 | char *buffer, | |
464 | size_t buflen, | |
465 | int *errnop) { | |
466 | int temp; | |
467 | char* name; | |
468 | ||
469 | if (init_afs()) return NSS_STATUS_UNAVAIL; | |
470 | ||
471 | name = buffer; | |
472 | temp = ptsid2name( uid, &buffer, &buflen); | |
473 | if (temp != NSS_STATUS_SUCCESS) { | |
474 | *errnop = ENOENT; | |
475 | return temp; | |
476 | } | |
477 | ||
908a6ebe | 478 | return fill_result_buf(uid, name, result_buf, buffer, buflen, errnop); |
479 | } | |
480 | ||
481 | /** | |
482 | * This function is exported; glibc will invoke it in order to gather | |
483 | * the user information (userid, homedir, shell) associated with a | |
484 | * username. | |
03b6b479 | 485 | */ |
908a6ebe | 486 | enum nss_status _nss_afs_getpwnam_r (char *name, |
487 | struct passwd *result_buf, | |
488 | char *buffer, | |
489 | size_t buflen, | |
490 | int *errnop) { | |
03b6b479 | 491 | uid_t uid; |
492 | int temp; | |
493 | ||
494 | if (init_afs()) return NSS_STATUS_UNAVAIL; | |
495 | ||
496 | temp = ptsname2id(name,&uid); | |
497 | if (temp != NSS_STATUS_SUCCESS) { | |
498 | *errnop = ENOENT; | |
499 | return temp; | |
500 | } | |
501 | ||
908a6ebe | 502 | return fill_result_buf(uid, name, result_buf, buffer, buflen, errnop); |
03b6b479 | 503 | } |
504 |