1 /*****************************************************************************
2 *
3 * Nagios-plugins parse_ini library
4 *
5 * License: GPL
6 * Copyright (c) 2007 Nagios Plugins Development Team
7 *
8 * Last Modified: $Date$
9 *
10 *
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 *
24 * $Id$
25 *
26 *****************************************************************************/
28 #include "common.h"
29 #include "utils_base.h"
30 #include "parse_ini.h"
31 #include <ctype.h>
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <unistd.h>
37 /* TODO: die like N::P if config file is not found */
39 /* np_ini_info contains the result of parsing a "locator" in the format
40 * [stanza_name][@config_filename] (check_foo@/etc/foo.ini, for example)
41 */
42 typedef struct {
43 char *file;
44 char *stanza;
45 } np_ini_info;
47 /* eat all characters from a FILE pointer until n is encountered */
48 #define GOBBLE_TO(f, c, n) do { (c)=fgetc((f)); } while((c)!=EOF && (c)!=(n))
50 /* internal function that returns the constructed defaults options */
51 static int read_defaults(FILE *f, const char *stanza, np_arg_list **opts);
52 /* internal function that converts a single line into options format */
53 static int add_option(FILE *f, np_arg_list **optlst);
54 /* internal function to find default file */
55 static char* default_file(void);
56 /* internal function to stat() files */
57 static int test_file(const char* env, int len, const char* file, char* temp_file);
59 /* parse_locator decomposes a string of the form
60 * [stanza][@filename]
61 * into its seperate parts
62 */
63 static void parse_locator(const char *locator, const char *def_stanza, np_ini_info *i){
64 size_t locator_len=0, stanza_len=0;
66 /* if locator is NULL we'll use default values */
67 if(locator){
68 locator_len=strlen(locator);
69 stanza_len=strcspn(locator, "@");
70 }
71 /* if a non-default stanza is provided */
72 if(stanza_len>0){
73 i->stanza=(char*)malloc(sizeof(char)*(stanza_len+1));
74 strncpy(i->stanza, locator, stanza_len);
75 i->stanza[stanza_len]='\0';
76 } else { /* otherwise we use the default stanza */
77 i->stanza=strdup(def_stanza);
78 }
79 /* if there is no @file part */
80 if(stanza_len==locator_len){
81 i->file=default_file();
82 } else {
83 i->file=strdup(&(locator[stanza_len+1]));
84 }
86 if(i->file==NULL || i->stanza==NULL){
87 die(STATE_UNKNOWN, _("malloc() failed!\n"));
88 }
89 }
91 /* this is the externally visible function used by extra_opts */
92 np_arg_list* np_get_defaults(const char *locator, const char *default_section){
93 FILE *inifile=NULL;
94 np_arg_list *defaults=NULL;
95 np_ini_info i;
97 parse_locator(locator, default_section, &i);
98 /* if a file was specified or if we're using the default file */
99 if(i.file != NULL && strlen(i.file) > 0){
100 if(strcmp(i.file, "-")==0){
101 inifile=stdin;
102 } else {
103 inifile=fopen(i.file, "r");
104 }
105 if(inifile==NULL) die(STATE_UNKNOWN, _("Can't read config file"));
106 if(read_defaults(inifile, i.stanza, &defaults)==FALSE)
107 die(STATE_UNKNOWN, _("Invalid section '%s' in config file '%s'\n"), i.stanza, i.file);
109 free(i.file);
110 if(inifile!=stdin) fclose(inifile);
111 }
112 free(i.stanza);
113 return defaults;
114 }
116 /* read_defaults is where the meat of the parsing takes place.
117 *
118 * note that this may be called by a setuid binary, so we need to
119 * be extra careful about user-supplied input (i.e. avoiding possible
120 * format string vulnerabilities, etc)
121 */
122 static int read_defaults(FILE *f, const char *stanza, np_arg_list **opts){
123 int c, status=FALSE;
124 size_t i, stanza_len;
125 enum { NOSTANZA, WRONGSTANZA, RIGHTSTANZA } stanzastate=NOSTANZA;
127 stanza_len=strlen(stanza);
129 /* our little stanza-parsing state machine. */
130 while((c=fgetc(f))!=EOF){
131 /* gobble up leading whitespace */
132 if(isspace(c)) continue;
133 switch(c){
134 /* globble up coment lines */
135 case ';':
136 case '#':
137 GOBBLE_TO(f, c, '\n');
138 break;
139 /* start of a stanza. check to see if it matches */
140 case '[':
141 stanzastate=WRONGSTANZA;
142 for(i=0; i<stanza_len; i++){
143 c=fgetc(f);
144 /* Strip leading whitespace */
145 if(i==0) for(c; isspace(c); c=fgetc(f));
146 /* nope, read to the end of the line */
147 if(c!=stanza[i]) {
148 GOBBLE_TO(f, c, '\n');
149 break;
150 }
151 }
152 /* if it matched up to here and the next char is ']'... */
153 if(i==stanza_len){
154 c=fgetc(f);
155 /* Strip trailing whitespace */
156 for(c; isspace(c); c=fgetc(f));
157 if(c==']') stanzastate=RIGHTSTANZA;
158 }
159 break;
160 /* otherwise, we're in the body of a stanza or a parse error */
161 default:
162 switch(stanzastate){
163 /* we never found the start of the first stanza, so
164 * we're dealing with a config error
165 */
166 case NOSTANZA:
167 die(STATE_UNKNOWN, _("Config file error"));
168 break;
169 /* we're in a stanza, but for a different plugin */
170 case WRONGSTANZA:
171 GOBBLE_TO(f, c, '\n');
172 break;
173 /* okay, this is where we start taking the config */
174 case RIGHTSTANZA:
175 ungetc(c, f);
176 if(add_option(f, opts)){
177 die(STATE_UNKNOWN, _("Config file error"));
178 }
179 status=TRUE;
180 break;
181 }
182 break;
183 }
184 }
185 return status;
186 }
188 /*
189 * read one line of input in the format
190 * ^option[[:space:]]*(=[[:space:]]*value)?
191 * and creates it as a cmdline argument
192 * --option[=value]
193 * appending it to the linked list optbuf.
194 */
195 static int add_option(FILE *f, np_arg_list **optlst){
196 np_arg_list *opttmp=*optlst, *optnew;
197 char *linebuf=NULL, *lineend=NULL, *optptr=NULL, *optend=NULL;
198 char *eqptr=NULL, *valptr=NULL, *spaceptr=NULL, *valend=NULL;
199 short done_reading=0, equals=0, value=0;
200 size_t cfg_len=0, read_sz=8, linebuf_sz=0, read_pos=0;
201 size_t opt_len=0, val_len=0;
203 /* read one line from the file */
204 while(!done_reading){
205 /* grow if necessary */
206 if(linebuf==NULL || read_pos+read_sz >= linebuf_sz){
207 linebuf_sz=(linebuf_sz>0)?linebuf_sz<<1:read_sz;
208 linebuf=realloc(linebuf, linebuf_sz);
209 if(linebuf==NULL) die(STATE_UNKNOWN, _("malloc() failed!\n"));
210 }
211 if(fgets(&linebuf[read_pos], read_sz, f)==NULL) done_reading=1;
212 else {
213 read_pos=strlen(linebuf);
214 if(linebuf[read_pos-1]=='\n') {
215 linebuf[--read_pos]='\0';
216 done_reading=1;
217 }
218 }
219 }
220 lineend=&linebuf[read_pos];
221 /* all that to read one line. isn't C fun? :) now comes the parsing :/ */
223 /* skip leading whitespace */
224 for(optptr=linebuf; optptr<lineend && isspace(*optptr); optptr++);
225 /* continue to '=' or EOL, watching for spaces that might precede it */
226 for(eqptr=optptr; eqptr<lineend && *eqptr!='='; eqptr++){
227 if(isspace(*eqptr) && optend==NULL) optend=eqptr;
228 else optend=NULL;
229 }
230 if(optend==NULL) optend=eqptr;
231 --optend;
232 /* ^[[:space:]]*=foo is a syntax error */
233 if(optptr==eqptr) die(STATE_UNKNOWN, _("Config file error\n"));
234 /* continue from '=' to start of value or EOL */
235 for(valptr=eqptr+1; valptr<lineend && isspace(*valptr); valptr++);
236 /* continue to the end of value */
237 for(valend=valptr; valend<lineend; valend++);
238 --valend;
239 /* Finally trim off trailing spaces */
240 for(valend; isspace(*valend); valend--);
241 /* calculate the length of "--foo" */
242 opt_len=1+optend-optptr;
243 /* 1-character params needs only one dash */
244 if(opt_len==1)
245 cfg_len=1+(opt_len);
246 else
247 cfg_len=2+(opt_len);
248 /* if valptr<lineend then we have to also allocate space for "=bar" */
249 if(valptr<lineend) {
250 equals=value=1;
251 val_len=1+valend-valptr;
252 cfg_len+=1+val_len;
253 }
254 /* if valptr==valend then we have "=" but no "bar" */
255 else if(valptr==lineend) {
256 equals=1;
257 cfg_len+=1;
258 }
259 /* A line with no equal sign isn't valid */
260 if(equals==0) die(STATE_UNKNOWN, _("Config file error\n"));
262 /* okay, now we have all the info we need, so we create a new np_arg_list
263 * element and set the argument...
264 */
265 optnew=(np_arg_list *)malloc(sizeof(np_arg_list));
266 optnew->next=NULL;
268 read_pos=0;
269 optnew->arg=(char *)malloc(cfg_len+1);
270 /* 1-character params needs only one dash */
271 if(opt_len==1) {
272 strncpy(&optnew->arg[read_pos], "-", 1);
273 read_pos+=1;
274 } else {
275 strncpy(&optnew->arg[read_pos], "--", 2);
276 read_pos+=2;
277 }
278 strncpy(&optnew->arg[read_pos], optptr, opt_len); read_pos+=opt_len;
279 if(value) {
280 optnew->arg[read_pos++]='=';
281 strncpy(&optnew->arg[read_pos], valptr, val_len); read_pos+=val_len;
282 }
283 optnew->arg[read_pos]='\0';
285 /* ...and put that to the end of the list */
286 if(*optlst==NULL) {
287 *optlst=optnew;
288 } else {
289 while(opttmp->next!=NULL) {
290 opttmp=opttmp->next;
291 }
292 opttmp->next = optnew;
293 }
295 free(linebuf);
296 return 0;
297 }
299 static char* default_file(void){
300 struct stat sb;
301 char *np_env=NULL, *default_file=NULL;
302 char temp_file[MAX_INPUT_BUFFER];
303 size_t len;
305 if((np_env=getenv("NAGIOS_CONFIG_PATH"))!=NULL) {
306 /* skip any starting colon... */
307 while(*np_env==':') np_env++;
308 /* Look for NP_DEFAULT_INI_FILENAME1 and NP_DEFAULT_INI_FILENAME2 in
309 * every PATHs defined (colon-separated).
310 */
311 while((len=strcspn(np_env,":"))>0){
312 /* Test NP_DEFAULT_INI_FILENAME[1-2] in current np_env token */
313 if(test_file(np_env,len,NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
314 test_file(np_env,len,NP_DEFAULT_INI_FILENAME2,temp_file)==1){
315 default_file=strdup(temp_file);
316 break;
317 }
319 /* Move on to the next token */
320 np_env+=len;
321 while(*np_env==':') np_env++;
322 } /* while(...) */
323 } /* if(getenv("NAGIOS_CONFIG_PATH")) */
325 /* Look for NP_DEFAULT_INI_FILENAME1 in NP_DEFAULT_INI_NAGIOS_PATH[1-4] */
326 if(!default_file){
327 if(test_file(NP_DEFAULT_INI_NAGIOS_PATH1,strlen(NP_DEFAULT_INI_NAGIOS_PATH1),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
328 test_file(NP_DEFAULT_INI_NAGIOS_PATH2,strlen(NP_DEFAULT_INI_NAGIOS_PATH2),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
329 test_file(NP_DEFAULT_INI_NAGIOS_PATH3,strlen(NP_DEFAULT_INI_NAGIOS_PATH3),NP_DEFAULT_INI_FILENAME1,temp_file)==1 ||
330 test_file(NP_DEFAULT_INI_NAGIOS_PATH4,strlen(NP_DEFAULT_INI_NAGIOS_PATH4),NP_DEFAULT_INI_FILENAME1,temp_file)==1)
331 default_file=strdup(temp_file);
332 }
334 /* Look for NP_DEFAULT_INI_FILENAME2 in NP_DEFAULT_INI_PATH[1-3] */
335 if(!default_file){
336 if(test_file(NP_DEFAULT_INI_PATH1,strlen(NP_DEFAULT_INI_PATH1),NP_DEFAULT_INI_FILENAME2,temp_file)==1 ||
337 test_file(NP_DEFAULT_INI_PATH2,strlen(NP_DEFAULT_INI_PATH2),NP_DEFAULT_INI_FILENAME2,temp_file)==1 ||
338 test_file(NP_DEFAULT_INI_PATH3,strlen(NP_DEFAULT_INI_PATH3),NP_DEFAULT_INI_FILENAME2,temp_file)==1)
339 default_file=strdup(temp_file);
340 }
342 /* Return default_file or empty string (should return NULL if we want plugins
343 * to die there)...
344 */
345 if(default_file)
346 return default_file;
347 return "";
348 }
350 /* put together len bytes from env and the filename and test for its
351 * existence. Returns 1 if found, 0 if not and -1 if test wasn't performed.
352 */
353 static int test_file(const char* env, int len, const char* file, char* temp_file){
354 struct stat sb;
356 /* test if len + filelen + '/' + '\0' fits in temp_file */
357 if((len+strlen(file)+2)>MAX_INPUT_BUFFER) return -1;
359 strncpy(temp_file,env,len);
360 temp_file[len]='\0';
361 strncat(temp_file,"/",len+1);
362 strncat(temp_file,file,len+strlen(file)+1);
364 if(stat(temp_file, &sb) != -1) return 1;
365 return 0;
366 }