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root/radiance/ray/src/common/header.c
Revision: 2.32
Committed: Thu Aug 2 18:33:42 2018 UTC (5 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad5R2
Changes since 2.31: +6 -5 lines
Log Message:
Created MAXFMTLEN to guard against buffer overrun attacks in header input

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: header.c,v 2.31 2017/05/10 18:02:08 greg Exp $";
3 #endif
4 /*
5 * header.c - routines for reading and writing information headers.
6 *
7 * Externals declared in resolu.h
8 *
9 * newheader(t,fp) start new information header identified by string t
10 * headidval(r,s) copy header identifier value in s to r
11 * dateval(t,s) get capture date value as UTC
12 * gmtval(t,s) get GMT as UTC
13 * fputdate(t,fp) put out the given UTC
14 * fputnow(fp) put out the current date and time
15 * printargs(ac,av,fp) print an argument list to fp, followed by '\n'
16 * formatval(r,s) copy the format value in s to r
17 * fputformat(s,fp) write "FORMAT=%s" to fp
18 * getheader(fp,f,p) read header from fp, calling f(s,p) on each line
19 * globmatch(pat, str) check for glob match of str against pat
20 * checkheader(i,p,o) check header format from i against p and copy to o
21 *
22 * To copy header from input to output, use getheader(fin, fputs, fout)
23 */
24
25 #include "copyright.h"
26
27 #include <ctype.h>
28
29 #include "rtio.h"
30 #include "resolu.h"
31
32 #define MAXLINE 2048
33
34 extern time_t timegm(struct tm *tm);
35
36 const char HDRSTR[] = "#?"; /* information header magic number */
37
38 const char FMTSTR[] = "FORMAT="; /* format identifier */
39
40 const char TMSTR[] = "CAPDATE="; /* capture date identifier */
41 const char GMTSTR[] = "GMT="; /* GMT identifier */
42
43 static gethfunc mycheck;
44
45
46 void
47 newheader( /* identifying line of information header */
48 const char *s,
49 FILE *fp
50 )
51 {
52 fputs(HDRSTR, fp);
53 fputs(s, fp);
54 putc('\n', fp);
55 }
56
57
58 int
59 headidval( /* get header id (return true if is id) */
60 char *r,
61 const char *s
62 )
63 {
64 const char *cp = HDRSTR;
65
66 while (*cp) if (*cp++ != *s++) return(0);
67 if (r == NULL) return(1);
68 while (*s && !isspace(*s)) *r++ = *s++;
69 *r = '\0';
70 return(1);
71 }
72
73
74 int
75 dateval( /* convert capture date line to UTC */
76 time_t *tloc,
77 const char *s
78 )
79 {
80 struct tm tms;
81 const char *cp = TMSTR;
82
83 while (*cp) if (*cp++ != *s++) return(0);
84 while (isspace(*s)) s++;
85 if (!*s) return(0);
86 if (sscanf(s, "%d:%d:%d %d:%d:%d",
87 &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
88 &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
89 return(0);
90 if (tloc == NULL)
91 return(1);
92 tms.tm_mon--;
93 tms.tm_year -= 1900;
94 tms.tm_isdst = -1; /* ask mktime() to figure out DST */
95 *tloc = mktime(&tms);
96 return(1);
97 }
98
99
100 int
101 gmtval( /* convert GMT date line to UTC */
102 time_t *tloc,
103 const char *s
104 )
105 {
106 struct tm tms;
107 const char *cp = GMTSTR;
108
109 while (*cp) if (*cp++ != *s++) return(0);
110 while (isspace(*s)) s++;
111 if (!*s) return(0);
112 if (sscanf(s, "%d:%d:%d %d:%d:%d",
113 &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
114 &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
115 return(0);
116 if (tloc == NULL)
117 return(1);
118 tms.tm_mon--;
119 tms.tm_year -= 1900;
120 *tloc = timegm(&tms);
121 return(1);
122 }
123
124
125 void
126 fputdate( /* write out the given time value (local & GMT) */
127 time_t tv,
128 FILE *fp
129 )
130 {
131 struct tm *tms;
132
133 tms = localtime(&tv);
134 if (tms != NULL)
135 fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", TMSTR,
136 tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
137 tms->tm_hour, tms->tm_min, tms->tm_sec);
138 tms = gmtime(&tv);
139 if (tms != NULL)
140 fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", GMTSTR,
141 tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
142 tms->tm_hour, tms->tm_min, tms->tm_sec);
143 }
144
145
146 void
147 fputnow( /* write out the current time */
148 FILE *fp
149 )
150 {
151 time_t tv;
152 time(&tv);
153 fputdate(tv, fp);
154 }
155
156
157 void
158 printargs( /* print arguments to a file */
159 int ac,
160 char **av,
161 FILE *fp
162 )
163 {
164 while (ac-- > 0) {
165 fputword(*av++, fp);
166 fputc(ac ? ' ' : '\n', fp);
167 }
168 }
169
170
171 int
172 formatval( /* get format value (return true if format) */
173 char fmt[MAXFMTLEN],
174 const char *s
175 )
176 {
177 const char *cp = FMTSTR;
178 char *r = fmt;
179
180 while (*cp) if (*cp++ != *s++) return(0);
181 while (isspace(*s)) s++;
182 if (!*s) return(0);
183 if (r == NULL) return(1);
184 do
185 *r++ = *s++;
186 while (*s && !isspace(*s) && r-fmt < MAXFMTLEN-1);
187 *r = '\0';
188 return(1);
189 }
190
191
192 void
193 fputformat( /* put out a format value */
194 const char *s,
195 FILE *fp
196 )
197 {
198 fputs(FMTSTR, fp);
199 fputs(s, fp);
200 putc('\n', fp);
201 }
202
203
204 int
205 getheader( /* get header from file */
206 FILE *fp,
207 gethfunc *f,
208 void *p
209 )
210 {
211 int rtotal = 0;
212 char buf[MAXLINE];
213
214 for ( ; ; ) {
215 int rval = 0;
216 buf[MAXLINE-2] = '\n';
217 if (fgets(buf, MAXLINE, fp) == NULL)
218 return(-1);
219 if (buf[buf[0]=='\r'] == '\n')
220 return(rtotal);
221 if (buf[MAXLINE-2] != '\n') {
222 ungetc(buf[MAXLINE-2], fp); /* prevent false end */
223 buf[MAXLINE-2] = '\0';
224 }
225 if (f != NULL && (rval = (*f)(buf, p)) < 0)
226 return(-1);
227 rtotal += rval;
228 }
229 }
230
231
232 struct check {
233 FILE *fp;
234 char fs[MAXFMTLEN];
235 };
236
237
238 static int
239 mycheck( /* check a header line for format info. */
240 char *s,
241 void *cp
242 )
243 {
244 if (!formatval(((struct check*)cp)->fs, s)
245 && ((struct check*)cp)->fp != NULL) {
246 fputs(s, ((struct check*)cp)->fp);
247 }
248 return(0);
249 }
250
251
252 int
253 globmatch( /* check for match of s against pattern p */
254 const char *p,
255 const char *s
256 )
257 {
258 int setmatch;
259
260 do {
261 switch (*p) {
262 case '?': /* match any character */
263 if (!*s++)
264 return(0);
265 break;
266 case '*': /* match any string */
267 while (p[1] == '*') p++;
268 do
269 if ( (p[1]=='?') | (p[1]==*s) &&
270 globmatch(p+1,s) )
271 return(1);
272 while (*s++);
273 return(0);
274 case '[': /* character set */
275 setmatch = *s == *++p;
276 if (!*p)
277 return(0);
278 while (*++p != ']') {
279 if (!*p)
280 return(0);
281 if (*p == '-') {
282 setmatch += (p[-1] <= *s && *s <= p[1]);
283 if (!*++p)
284 break;
285 } else
286 setmatch += (*p == *s);
287 }
288 if (!setmatch)
289 return(0);
290 s++;
291 break;
292 case '\\': /* literal next */
293 p++;
294 /* fall through */
295 default: /* normal character */
296 if (*p != *s)
297 return(0);
298 s++;
299 break;
300 }
301 } while (*p++);
302 return(1);
303 }
304
305
306 /*
307 * Checkheader(fin,fmt,fout) returns a value of 1 if the input format
308 * matches the specification in fmt, 0 if no input format was found,
309 * and -1 if the input format does not match or there is an
310 * error reading the header. If fmt is empty, then -1 is returned
311 * if any input format is found (or there is an error), and 0 otherwise.
312 * If fmt contains any '*' or '?' characters, then checkheader
313 * does wildcard expansion and copies a matching result into fmt.
314 * Be sure that fmt is big enough to hold the match in such cases,
315 * and that it is not a static, read-only string!
316 * The input header (minus any format lines) is copied to fout
317 * if fout is not NULL.
318 */
319
320 int
321 checkheader(
322 FILE *fin,
323 char fmt[MAXFMTLEN],
324 FILE *fout
325 )
326 {
327 struct check cdat;
328 char *cp;
329
330 cdat.fp = fout;
331 cdat.fs[0] = '\0';
332 if (getheader(fin, mycheck, &cdat) < 0)
333 return(-1);
334 if (!cdat.fs[0])
335 return(0);
336 for (cp = fmt; *cp; cp++) /* check for globbing */
337 if ((*cp == '?') | (*cp == '*')) {
338 if (globmatch(fmt, cdat.fs)) {
339 strcpy(fmt, cdat.fs);
340 return(1);
341 } else
342 return(-1);
343 }
344 return(strcmp(fmt, cdat.fs) ? -1 : 1); /* literal match */
345 }