Commit | Line | Data |
---|---|---|
693d8207 GR |
1 | /* Copyright 1988,1990,1993,1994 by Paul Vixie |
2 | * All rights reserved | |
3 | * | |
4 | * Distribute freely, except: don't remove my name from the source or | |
5 | * documentation (don't take credit for my work), mark your changes (don't | |
6 | * get me blamed for your possible bugs), don't alter or remove this | |
7 | * notice. May be sold if buildable source is provided to buyer. No | |
8 | * warrantee of any kind, express or implied, is included with this | |
9 | * software; use at your own risk, responsibility for damages (if any) to | |
10 | * anyone resulting from the use of this software rests entirely with the | |
11 | * user. | |
12 | * | |
13 | * Send bug reports, bug fixes, enhancements, requests, flames, etc., and | |
14 | * I'll try to keep a version up to date. I can be reached as follows: | |
15 | * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul | |
16 | * From Id: database.c,v 2.8 1994/01/15 20:43:43 vixie Exp | |
17 | */ | |
18 | ||
19 | #if !defined(lint) && !defined(LINT) | |
20 | static char rcsid[] = "$Header: $"; | |
21 | #endif | |
22 | ||
23 | /* vix 26jan87 [RCS has the log] | |
24 | */ | |
25 | ||
26 | ||
27 | #include "cron.h" | |
28 | #include <fcntl.h> | |
29 | #include <sys/stat.h> | |
30 | #include <sys/file.h> | |
31 | ||
32 | ||
33 | #define TMAX(a,b) ((a)>(b)?(a):(b)) | |
34 | ||
35 | ||
36 | static void process_crontab __P((char *, char *, char *, | |
37 | struct stat *, | |
38 | cron_db *, cron_db *)); | |
39 | ||
40 | ||
41 | void | |
42 | load_database(old_db) | |
43 | cron_db *old_db; | |
44 | { | |
45 | DIR *dir; | |
46 | struct stat statbuf; | |
47 | struct stat syscron_stat; | |
48 | DIR_T *dp; | |
49 | cron_db new_db; | |
50 | user *u, *nu; | |
51 | ||
52 | Debug(DLOAD, ("[%d] load_database()\n", getpid())) | |
53 | ||
54 | /* before we start loading any data, do a stat on SPOOL_DIR | |
55 | * so that if anything changes as of this moment (i.e., before we've | |
56 | * cached any of the database), we'll see the changes next time. | |
57 | */ | |
58 | if (stat(SPOOL_DIR, &statbuf) < OK) { | |
59 | log_it("CRON", getpid(), "STAT FAILED", SPOOL_DIR); | |
60 | (void) exit(ERROR_EXIT); | |
61 | } | |
62 | ||
63 | /* track system crontab file | |
64 | */ | |
65 | if (stat(SYSCRONTAB, &syscron_stat) < OK) | |
66 | syscron_stat.st_mtime = 0; | |
67 | ||
68 | /* if spooldir's mtime has not changed, we don't need to fiddle with | |
69 | * the database. | |
70 | * | |
71 | * Note that old_db->mtime is initialized to 0 in main(), and | |
72 | * so is guaranteed to be different than the stat() mtime the first | |
73 | * time this function is called. | |
74 | */ | |
75 | if (old_db->mtime == TMAX(statbuf.st_mtime, syscron_stat.st_mtime)) { | |
76 | Debug(DLOAD, ("[%d] spool dir mtime unch, no load needed.\n", | |
77 | getpid())) | |
78 | return; | |
79 | } | |
80 | ||
81 | /* something's different. make a new database, moving unchanged | |
82 | * elements from the old database, reloading elements that have | |
83 | * actually changed. Whatever is left in the old database when | |
84 | * we're done is chaff -- crontabs that disappeared. | |
85 | */ | |
86 | new_db.mtime = TMAX(statbuf.st_mtime, syscron_stat.st_mtime); | |
87 | new_db.head = new_db.tail = NULL; | |
88 | ||
89 | if (syscron_stat.st_mtime) { | |
90 | process_crontab("root", "*system*", | |
91 | SYSCRONTAB, &syscron_stat, | |
92 | &new_db, old_db); | |
93 | } | |
94 | ||
95 | /* we used to keep this dir open all the time, for the sake of | |
96 | * efficiency. however, we need to close it in every fork, and | |
97 | * we fork a lot more often than the mtime of the dir changes. | |
98 | */ | |
99 | if (!(dir = opendir(SPOOL_DIR))) { | |
100 | log_it("CRON", getpid(), "OPENDIR FAILED", SPOOL_DIR); | |
101 | (void) exit(ERROR_EXIT); | |
102 | } | |
103 | ||
104 | while (NULL != (dp = readdir(dir))) { | |
105 | char fname[MAXNAMLEN+1], | |
106 | tabname[MAXNAMLEN+1]; | |
107 | ||
108 | /* avoid file names beginning with ".". this is good | |
109 | * because we would otherwise waste two guaranteed calls | |
110 | * to getpwnam() for . and .., and also because user names | |
111 | * starting with a period are just too nasty to consider. | |
112 | */ | |
113 | if (dp->d_name[0] == '.') | |
114 | continue; | |
115 | ||
116 | (void) strcpy(fname, dp->d_name); | |
117 | sprintf(tabname, CRON_TAB(fname)); | |
118 | ||
119 | process_crontab(fname, fname, tabname, | |
120 | &statbuf, &new_db, old_db); | |
121 | } | |
122 | closedir(dir); | |
123 | ||
124 | /* if we don't do this, then when our children eventually call | |
125 | * getpwnam() in do_command.c's child_process to verify MAILTO=, | |
126 | * they will screw us up (and v-v). | |
127 | */ | |
128 | endpwent(); | |
129 | ||
130 | /* whatever's left in the old database is now junk. | |
131 | */ | |
132 | Debug(DLOAD, ("unlinking old database:\n")) | |
133 | for (u = old_db->head; u != NULL; u = nu) { | |
134 | Debug(DLOAD, ("\t%s\n", u->name)) | |
135 | nu = u->next; | |
136 | unlink_user(old_db, u); | |
137 | free_user(u); | |
138 | } | |
139 | ||
140 | /* overwrite the database control block with the new one. | |
141 | */ | |
142 | *old_db = new_db; | |
143 | Debug(DLOAD, ("load_database is done\n")) | |
144 | } | |
145 | ||
146 | ||
147 | void | |
148 | link_user(db, u) | |
149 | cron_db *db; | |
150 | user *u; | |
151 | { | |
152 | if (db->head == NULL) | |
153 | db->head = u; | |
154 | if (db->tail) | |
155 | db->tail->next = u; | |
156 | u->prev = db->tail; | |
157 | u->next = NULL; | |
158 | db->tail = u; | |
159 | } | |
160 | ||
161 | ||
162 | void | |
163 | unlink_user(db, u) | |
164 | cron_db *db; | |
165 | user *u; | |
166 | { | |
167 | if (u->prev == NULL) | |
168 | db->head = u->next; | |
169 | else | |
170 | u->prev->next = u->next; | |
171 | ||
172 | if (u->next == NULL) | |
173 | db->tail = u->prev; | |
174 | else | |
175 | u->next->prev = u->prev; | |
176 | } | |
177 | ||
178 | ||
179 | user * | |
180 | find_user(db, name) | |
181 | cron_db *db; | |
182 | char *name; | |
183 | { | |
184 | char *env_get(); | |
185 | user *u; | |
186 | ||
187 | for (u = db->head; u != NULL; u = u->next) | |
188 | if (!strcmp(u->name, name)) | |
189 | break; | |
190 | return u; | |
191 | } | |
192 | ||
193 | ||
194 | static void | |
195 | process_crontab(uname, fname, tabname, statbuf, new_db, old_db) | |
196 | char *uname; | |
197 | char *fname; | |
198 | char *tabname; | |
199 | struct stat *statbuf; | |
200 | cron_db *new_db; | |
201 | cron_db *old_db; | |
202 | { | |
203 | struct passwd *pw = NULL; | |
204 | int crontab_fd = OK - 1; | |
205 | user *u; | |
206 | ||
207 | if (strcmp(fname, "*system*") && !(pw = getpwnam(uname))) { | |
208 | /* file doesn't have a user in passwd file. | |
209 | */ | |
210 | log_it(fname, getpid(), "ORPHAN", "no passwd entry"); | |
211 | goto next_crontab; | |
212 | } | |
213 | ||
214 | if ((crontab_fd = open(tabname, O_RDONLY, 0)) < OK) { | |
215 | /* crontab not accessible? | |
216 | */ | |
217 | log_it(fname, getpid(), "CAN'T OPEN", tabname); | |
218 | goto next_crontab; | |
219 | } | |
220 | ||
221 | if (fstat(crontab_fd, statbuf) < OK) { | |
222 | log_it(fname, getpid(), "FSTAT FAILED", tabname); | |
223 | goto next_crontab; | |
224 | } | |
225 | ||
226 | Debug(DLOAD, ("\t%s:", fname)) | |
227 | u = find_user(old_db, fname); | |
228 | if (u != NULL) { | |
229 | /* if crontab has not changed since we last read it | |
230 | * in, then we can just use our existing entry. | |
231 | */ | |
232 | if (u->mtime == statbuf->st_mtime) { | |
233 | Debug(DLOAD, (" [no change, using old data]")) | |
234 | unlink_user(old_db, u); | |
235 | link_user(new_db, u); | |
236 | goto next_crontab; | |
237 | } | |
238 | ||
239 | /* before we fall through to the code that will reload | |
240 | * the user, let's deallocate and unlink the user in | |
241 | * the old database. This is more a point of memory | |
242 | * efficiency than anything else, since all leftover | |
243 | * users will be deleted from the old database when | |
244 | * we finish with the crontab... | |
245 | */ | |
246 | Debug(DLOAD, (" [delete old data]")) | |
247 | unlink_user(old_db, u); | |
248 | free_user(u); | |
249 | log_it(fname, getpid(), "RELOAD", tabname); | |
250 | } | |
251 | u = load_user(crontab_fd, pw, fname); | |
252 | if (u != NULL) { | |
253 | u->mtime = statbuf->st_mtime; | |
254 | link_user(new_db, u); | |
255 | } | |
256 | ||
257 | next_crontab: | |
258 | if (crontab_fd >= OK) { | |
259 | Debug(DLOAD, (" [done]\n")) | |
260 | close(crontab_fd); | |
261 | } | |
262 | } |