1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <fmtmsg.h>
19 #include <libc-lock.h>
20 #include <stdio.h>
21 #include <stdint.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/syslog.h>
25 #include <wchar.h>
26 
27 
28 /* We have global data, protect the modification.  */
29 __libc_lock_define_initialized (static, lock)
30 
31 
32 enum
33 {
34   label_mask = 0x01,
35   severity_mask = 0x02,
36   text_mask = 0x04,
37   action_mask = 0x08,
38   tag_mask = 0x10,
39   all_mask = label_mask | severity_mask | text_mask | action_mask | tag_mask
40 };
41 
42 static const struct
43 {
44   uint32_t len;
45   /* Adjust the size if new elements are added.  */
46   const char name[12];
47 } keywords[] =
48   {
49     { 5, "label" },
50     { 8, "severity" },
51     { 4, "text" },
52     { 6, "action"},
53     { 3, "tag" }
54   };
55 #define NKEYWORDS (sizeof (keywords) / sizeof (keywords[0]))
56 
57 
58 struct severity_info
59 {
60   int severity;
61   const char *string;
62   struct severity_info *next;
63 };
64 
65 
66 /* List of known severities.  */
67 static const struct severity_info nosev =
68 {
69   MM_NOSEV, "", NULL
70 };
71 static const struct severity_info haltsev =
72 {
73   MM_HALT, "HALT", (struct severity_info *) &nosev
74 };
75 static const struct severity_info errorsev =
76 {
77   MM_ERROR, "ERROR", (struct severity_info *) &haltsev
78 };
79 static const struct severity_info warningsev =
80 {
81   MM_WARNING, "WARNING", (struct severity_info *) &errorsev
82 };
83 static const struct severity_info infosev =
84 {
85   MM_INFO, "INFO", (struct severity_info *) &warningsev
86 };
87 
88 /* Start of the list.  */
89 static struct severity_info *severity_list = (struct severity_info *) &infosev;
90 
91 /* Mask of values we will print.  */
92 static int print;
93 
94 /* Prototypes for local functions.  */
95 static void init (void);
96 static int internal_addseverity (int severity, const char *string);
97 
98 
99 int
fmtmsg(long int classification,const char * label,int severity,const char * text,const char * action,const char * tag)100 fmtmsg (long int classification, const char *label, int severity,
101 	const char *text, const char *action, const char *tag)
102 {
103   __libc_once_define (static, once);
104   struct severity_info *severity_rec;
105 
106   /* Make sure everything is initialized.  */
107   __libc_once (once, init);
108 
109   /* Start the real work.  First check whether the input is ok.  */
110   if (label != MM_NULLLBL)
111     {
112       /* Must be two fields, separated by a colon.  */
113       const char *cp = strchr (label, ':');
114       if (cp == NULL)
115 	return MM_NOTOK;
116 
117       /* The first field must not contain more than 10 bytes.  */
118       if (cp - label > 10
119 	  /* The second field must not have more than 14 bytes.  */
120 	  || strlen (cp + 1) > 14)
121 	return MM_NOTOK;
122     }
123 
124   /* We do not want this call to be cut short by a thread
125      cancellation.  Therefore disable cancellation for now.  */
126   int state = PTHREAD_CANCEL_ENABLE;
127   __pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
128 
129   __libc_lock_lock (lock);
130 
131   for (severity_rec = severity_list; severity_rec != NULL;
132        severity_rec = severity_rec->next)
133     if (severity == severity_rec->severity)
134       /* Bingo.  */
135       break;
136 
137   /* If we don't know anything about the severity level return an error.  */
138   int result = MM_NOTOK;
139   if (severity_rec != NULL)
140     {
141       result = MM_OK;
142 
143       /* Now we can print.  */
144       if (classification & MM_PRINT)
145 	{
146 	  int do_label = (print & label_mask) && label != MM_NULLLBL;
147 	  int do_severity = (print & severity_mask) && severity != MM_NULLSEV;
148 	  int do_text = (print & text_mask) && text != MM_NULLTXT;
149 	  int do_action = (print & action_mask) && action != MM_NULLACT;
150 	  int do_tag = (print & tag_mask) && tag != MM_NULLTAG;
151 	  int need_colon = (do_label
152 			    && (do_severity | do_text | do_action | do_tag));
153 
154 	  if (__fxprintf (stderr, "%s%s%s%s%s%s%s%s%s%s\n",
155 			  do_label ? label : "",
156 			  need_colon ? ": " : "",
157 			  do_severity ? severity_rec->string : "",
158 			  do_severity && (do_text | do_action | do_tag)
159 			  ? ": " : "",
160 			  do_text ? text : "",
161 			  do_text && (do_action | do_tag) ? "\n" : "",
162 			  do_action ? "TO FIX: " : "",
163 			  do_action ? action : "",
164 			  do_action && do_tag ? "  " : "",
165 			  do_tag ? tag : "") < 0)
166 	    /* Oh, oh.  An error occurred during the output.  */
167 	    result = MM_NOMSG;
168 	}
169 
170       if (classification & MM_CONSOLE)
171 	{
172 	  int do_label = label != MM_NULLLBL;
173 	  int do_severity = severity != MM_NULLSEV;
174 	  int do_text = text != MM_NULLTXT;
175 	  int do_action = action != MM_NULLACT;
176 	  int do_tag = tag != MM_NULLTAG;
177 	  int need_colon = (do_label
178 			    && (do_severity | do_text | do_action | do_tag));
179 
180 	  syslog (LOG_ERR, "%s%s%s%s%s%s%s%s%s%s\n",
181 		  do_label ? label : "",
182 		  need_colon ? ": " : "",
183 		  do_severity ? severity_rec->string : "",
184 		  do_severity && (do_text | do_action | do_tag) ? ": " : "",
185 		  do_text ? text : "",
186 		  do_text && (do_action | do_tag) ? "\n" : "",
187 		  do_action ? "TO FIX: " : "",
188 		  do_action ? action : "",
189 		  do_action && do_tag ? "  " : "",
190 		  do_tag ? tag : "");
191 	}
192     }
193 
194   __libc_lock_unlock (lock);
195 
196   __pthread_setcancelstate (state, NULL);
197 
198   return result;
199 }
200 
201 
202 /* Initialize from environment variable content.  */
203 static void
init(void)204 init (void)
205 {
206   const char *msgverb_var = getenv ("MSGVERB");
207   const char *sevlevel_var = getenv ("SEV_LEVEL");
208 
209   if (msgverb_var != NULL && msgverb_var[0] != '\0')
210     {
211       /* Using this extra variable allows us to work without locking.  */
212       do
213 	{
214 	  size_t cnt;
215 
216 	  for (cnt = 0; cnt < NKEYWORDS; ++cnt)
217 	    if (memcmp (msgverb_var,
218 			keywords[cnt].name, keywords[cnt].len) == 0
219 		&& (msgverb_var[keywords[cnt].len] == ':'
220 		    || msgverb_var[keywords[cnt].len] == '\0'))
221 	      break;
222 
223 	  if (cnt < NKEYWORDS)
224 	    {
225 	      print |= 1 << cnt;
226 
227 	      msgverb_var += keywords[cnt].len;
228 	      if (msgverb_var[0] == ':')
229 		++msgverb_var;
230 	    }
231 	  else
232 	    {
233 	      /* We found an illegal keyword in the environment
234 		 variable.  The specifications say that we print all
235 		 fields.  */
236 	      print = all_mask;
237 	      break;
238 	    }
239 	}
240       while (msgverb_var[0] != '\0');
241     }
242   else
243     print = all_mask;
244 
245 
246   if (sevlevel_var != NULL)
247     {
248       __libc_lock_lock (lock);
249 
250       while (sevlevel_var[0] != '\0')
251 	{
252 	  const char *end = __strchrnul (sevlevel_var, ':');
253 	  int level;
254 
255 	  /* First field: keyword.  This is not used here but it must be
256 	     present.  */
257 	  while (sevlevel_var < end)
258 	    if (*sevlevel_var++ == ',')
259 	      break;
260 
261 	  if (sevlevel_var < end)
262 	    {
263 	      /* Second field: severity level, a number.  */
264 	      char *cp;
265 
266 	      level = strtol (sevlevel_var, &cp, 0);
267 	      if (cp != sevlevel_var && cp < end && *cp++ == ','
268 		  && level > MM_INFO)
269 		{
270 		  const char *new_string;
271 
272 		  new_string = __strndup (cp, end - cp);
273 
274 		  if (new_string != NULL
275 		      && (internal_addseverity (level, new_string)
276 			  != MM_OK))
277 		    free ((char *) new_string);
278 		}
279 	    }
280 
281 	  sevlevel_var = end + (*end == ':' ? 1 : 0);
282 	}
283 
284       __libc_lock_unlock (lock);
285     }
286 }
287 
288 
289 /* Add the new entry to the list.  */
290 static int
internal_addseverity(int severity,const char * string)291 internal_addseverity (int severity, const char *string)
292 {
293   struct severity_info *runp, *lastp;
294   int result = MM_OK;
295 
296   /* First see if there is already a record for the severity level.  */
297   for (runp = severity_list, lastp = NULL; runp != NULL; runp = runp->next)
298     if (runp->severity == severity)
299       break;
300     else
301       lastp = runp;
302 
303   if (runp != NULL)
304     {
305       if (string != NULL)
306 	/* Change the string.  */
307 	runp->string = string;
308       else
309 	{
310 	  /* Remove the severity class.  */
311 	  if (lastp == NULL)
312 	    severity_list = runp->next;
313 	  else
314 	    lastp->next = runp->next;
315 
316 	  free (runp);
317 	}
318     }
319   else if (string != NULL)
320     {
321       runp = malloc (sizeof (*runp));
322       if (runp == NULL)
323 	result = MM_NOTOK;
324       else
325 	{
326 	  runp->severity = severity;
327 	  runp->next = severity_list;
328 	  runp->string = string;
329 	  severity_list = runp;
330 	}
331     }
332   else
333     /* We tried to remove a non-existing severity class.  */
334     result = MM_NOTOK;
335 
336   return result;
337 }
338 
339 
340 /* Add new severity level or remove old one.  */
341 int
__addseverity(int severity,const char * string)342 __addseverity (int severity, const char *string)
343 {
344   int result;
345 
346   /* Prevent illegal SEVERITY values.  */
347   if (severity <= MM_INFO)
348     return MM_NOTOK;
349 
350   /* Protect the global data.  */
351   __libc_lock_lock (lock);
352 
353   /* Do the real work.  */
354   result = internal_addseverity (severity, string);
355 
356   /* Release the lock.  */
357   __libc_lock_unlock (lock);
358 
359   return result;
360 }
weak_alias(__addseverity,addseverity)361 weak_alias (__addseverity, addseverity)
362 
363 
364 libc_freeres_fn (free_mem)
365 {
366   struct severity_info *runp = severity_list;
367 
368   while (runp != NULL)
369     if (runp->severity > MM_INFO)
370       {
371 	/* This is data we have to release.  */
372 	struct severity_info *here = runp;
373 	runp = runp->next;
374 	free (here);
375       }
376     else
377       runp = runp->next;
378 }
379