src/common/header.c

#ifndef lint
static const char       RCSid[] = "$Id: header.c,v 2.31 2017/05/10 18:02:08 greg Exp $";
#endif
/*
 *  header.c - routines for reading and writing information headers.
 *
 *  Externals declared in resolu.h
 *
 *  newheader(t,fp)     start new information header identified by string t
 *  headidval(r,s)      copy header identifier value in s to r
 *  dateval(t,s)        get capture date value as UTC
 *  gmtval(t,s)         get GMT as UTC
 *  fputdate(t,fp)      put out the given UTC
 *  fputnow(fp)         put out the current date and time
 *  printargs(ac,av,fp) print an argument list to fp, followed by '\n'
 *  formatval(r,s)      copy the format value in s to r
 *  fputformat(s,fp)    write "FORMAT=%s" to fp
 *  getheader(fp,f,p)   read header from fp, calling f(s,p) on each line
 *  globmatch(pat, str) check for glob match of str against pat
 *  checkheader(i,p,o)  check header format from i against p and copy to o
 *
 *  To copy header from input to output, use getheader(fin, fputs, fout)
 */

#include "copyright.h"

#include  <ctype.h>

#include  "rtio.h"
#include  "resolu.h"

#define  MAXLINE        2048

extern time_t           timegm(struct tm *tm);

const char  HDRSTR[] = "#?";            /* information header magic number */

const char  FMTSTR[] = "FORMAT=";       /* format identifier */

const char  TMSTR[] = "CAPDATE=";       /* capture date identifier */
const char  GMTSTR[] = "GMT=";          /* GMT identifier */

static gethfunc mycheck;


void
newheader(              /* identifying line of information header */
        const char  *s,
        FILE  *fp
)
{
        fputs(HDRSTR, fp);
        fputs(s, fp);
        putc('\n', fp);
}


int
headidval(                      /* get header id (return true if is id) */
        char  *r,
        const char      *s
)
{
        const char  *cp = HDRSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        if (r == NULL) return(1);
        while (*s && !isspace(*s)) *r++ = *s++;
        *r = '\0';
        return(1);
}


int
dateval(                /* convert capture date line to UTC */
        time_t  *tloc,
        const char      *s
)
{
        struct tm       tms;
        const char      *cp = TMSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (sscanf(s, "%d:%d:%d %d:%d:%d",
                        &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
                        &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
                return(0);
        if (tloc == NULL)
                return(1);
        tms.tm_mon--;
        tms.tm_year -= 1900;
        tms.tm_isdst = -1;      /* ask mktime() to figure out DST */
        *tloc = mktime(&tms);
        return(1);
}


int
gmtval(                 /* convert GMT date line to UTC */
        time_t  *tloc,
        const char      *s
)
{
        struct tm       tms;
        const char      *cp = GMTSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (sscanf(s, "%d:%d:%d %d:%d:%d",
                        &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
                        &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
                return(0);
        if (tloc == NULL)
                return(1);
        tms.tm_mon--;
        tms.tm_year -= 1900;
        *tloc = timegm(&tms);
        return(1);
}


void
fputdate(               /* write out the given time value (local & GMT) */
        time_t  tv,
        FILE    *fp
)
{
        struct tm       *tms;

        tms = localtime(&tv);
        if (tms != NULL)
                fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", TMSTR,
                                tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
                                tms->tm_hour, tms->tm_min, tms->tm_sec);
        tms = gmtime(&tv);
        if (tms != NULL)
                fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", GMTSTR,
                                tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
                                tms->tm_hour, tms->tm_min, tms->tm_sec);
}


void
fputnow(                        /* write out the current time */
        FILE    *fp
)
{
        time_t  tv;
        time(&tv);
        fputdate(tv, fp);
}


void
printargs(              /* print arguments to a file */
        int  ac,
        char  **av,
        FILE  *fp
)
{
        while (ac-- > 0) {
                fputword(*av++, fp);
                fputc(ac ? ' ' : '\n', fp);
        }
}


int
formatval(                      /* get format value (return true if format) */
        char  fmt[MAXFMTLEN],
        const char  *s
)
{
        const char  *cp = FMTSTR;
        char  *r = fmt;

        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (r == NULL) return(1);
        do
                *r++ = *s++;
        while (*s && !isspace(*s) && r-fmt < MAXFMTLEN-1);
        *r = '\0';
        return(1);
}


void
fputformat(             /* put out a format value */
        const char  *s,
        FILE  *fp
)
{
        fputs(FMTSTR, fp);
        fputs(s, fp);
        putc('\n', fp);
}


int
getheader(              /* get header from file */
        FILE  *fp,
        gethfunc *f,
        void  *p
)
{
        int   rtotal = 0;
        char  buf[MAXLINE];

        for ( ; ; ) {
                int     rval = 0;
                buf[MAXLINE-2] = '\n';
                if (fgets(buf, MAXLINE, fp) == NULL)
                        return(-1);
                if (buf[buf[0]=='\r'] == '\n')
                        return(rtotal);
                if (buf[MAXLINE-2] != '\n') {
                        ungetc(buf[MAXLINE-2], fp);     /* prevent false end */
                        buf[MAXLINE-2] = '\0';
                }
                if (f != NULL && (rval = (*f)(buf, p)) < 0)
                        return(-1);
                rtotal += rval;
        }
}


struct check {
        FILE    *fp;
        char    fs[MAXFMTLEN];
};


static int
mycheck(                        /* check a header line for format info. */
        char  *s,
        void  *cp
)
{
        if (!formatval(((struct check*)cp)->fs, s)
                        && ((struct check*)cp)->fp != NULL) {
                fputs(s, ((struct check*)cp)->fp);
        }
        return(0);
}


int
globmatch(                      /* check for match of s against pattern p */
        const char      *p,
        const char      *s
)
{
        int     setmatch;

        do {
                switch (*p) {
                case '?':                       /* match any character */
                        if (!*s++)
                                return(0);
                        break;
                case '*':                       /* match any string */
                        while (p[1] == '*') p++;
                        do
                                if ( (p[1]=='?') | (p[1]==*s) &&
                                                globmatch(p+1,s) )
                                        return(1);
                        while (*s++);
                        return(0);
                case '[':                       /* character set */
                        setmatch = *s == *++p;
                        if (!*p)
                                return(0);
                        while (*++p != ']') {
                                if (!*p)
                                        return(0);
                                if (*p == '-') {
                                        setmatch += (p[-1] <= *s && *s <= p[1]);
                                        if (!*++p)
                                                break;
                                } else
                                        setmatch += (*p == *s);
                        }
                        if (!setmatch)
                                return(0);
                        s++;
                        break;
                case '\\':                      /* literal next */
                        p++;
                /* fall through */
                default:                        /* normal character */
                        if (*p != *s)
                                return(0);
                        s++;
                        break;
                }
        } while (*p++);
        return(1);
}


/*
 * Checkheader(fin,fmt,fout) returns a value of 1 if the input format
 * matches the specification in fmt, 0 if no input format was found,
 * and -1 if the input format does not match or there is an
 * error reading the header.  If fmt is empty, then -1 is returned
 * if any input format is found (or there is an error), and 0 otherwise.
 * If fmt contains any '*' or '?' characters, then checkheader
 * does wildcard expansion and copies a matching result into fmt.
 * Be sure that fmt is big enough to hold the match in such cases,
 * and that it is not a static, read-only string!
 * The input header (minus any format lines) is copied to fout
 * if fout is not NULL.
 */

int
checkheader(
        FILE  *fin,
        char  fmt[MAXFMTLEN],
        FILE  *fout
)
{
        struct check    cdat;
        char    *cp;

        cdat.fp = fout;
        cdat.fs[0] = '\0';
        if (getheader(fin, mycheck, &cdat) < 0)
                return(-1);
        if (!cdat.fs[0])
                return(0);
        for (cp = fmt; *cp; cp++)               /* check for globbing */
                if ((*cp == '?') | (*cp == '*')) {
                        if (globmatch(fmt, cdat.fs)) {
                                strcpy(fmt, cdat.fs);
                                return(1);
                        } else
                                return(-1);
                }
        return(strcmp(fmt, cdat.fs) ? -1 : 1);  /* literal match */
}
Revision:	2.32
Committed:	Thu Aug 2 18:33:42 2018 UTC (7 years, 3 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
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.32	static const char RCSid[] = "$Id: header.c,v 2.31 2017/05/10 18:02:08 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* header.c - routines for reading and writing information headers.
6			*
7	greg	2.11	* Externals declared in resolu.h
8	greg	1.3	*
9	greg	2.4	* newheader(t,fp) start new information header identified by string t
10			* headidval(r,s) copy header identifier value in s to r
11	greg	2.25	* 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	greg	2.11	* fputnow(fp) put out the current date and time
15	greg	2.3	* printargs(ac,av,fp) print an argument list to fp, followed by '\n'
16	greg	1.3	* 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	greg	2.6	* globmatch(pat, str) check for glob match of str against pat
20	greg	1.3	* 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	greg	1.1	*/
24
25	greg	2.12	#include "copyright.h"
26	greg	2.11
27	greg	1.3	#include <ctype.h>
28	schorsch	2.17
29	greg	2.18	#include "rtio.h"
30			#include "resolu.h"
31	schorsch	2.14
32	greg	2.24	#define MAXLINE 2048
33	greg	2.2
34	greg	2.26	extern time_t timegm(struct tm *tm);
35
36	greg	2.25	const char HDRSTR[] = "#?"; /* information header magic number */
37	greg	1.2
38	greg	2.25	const char FMTSTR[] = "FORMAT="; /* format identifier */
39	greg	1.2
40	greg	2.25	const char TMSTR[] = "CAPDATE="; /* capture date identifier */
41			const char GMTSTR[] = "GMT="; /* GMT identifier */
42	greg	2.16
43	schorsch	2.22	static gethfunc mycheck;
44	greg	2.4
45	greg	2.11
46	greg	2.29	void
47	schorsch	2.22	newheader( /* identifying line of information header */
48	greg	2.31	const char *s,
49	greg	2.25	FILE *fp
50	schorsch	2.22	)
51	greg	2.4	{
52			fputs(HDRSTR, fp);
53			fputs(s, fp);
54			putc('\n', fp);
55			}
56
57
58	greg	2.29	int
59	schorsch	2.22	headidval( /* get header id (return true if is id) */
60	greg	2.25	char *r,
61	greg	2.31	const char *s
62	schorsch	2.22	)
63	greg	2.4	{
64	greg	2.25	const char *cp = HDRSTR;
65	greg	2.4
66			while (cp) if (cp++ != *s++) return(0);
67			if (r == NULL) return(1);
68	gregl	2.9	while (s && !isspace(s)) r++ = s++;
69	greg	2.4	*r = '\0';
70			return(1);
71			}
72
73
74	greg	2.29	int
75	greg	2.25	dateval( /* convert capture date line to UTC */
76	schorsch	2.22	time_t *tloc,
77	greg	2.31	const char *s
78	schorsch	2.22	)
79	greg	2.11	{
80			struct tm tms;
81	greg	2.25	const char *cp = TMSTR;
82	greg	2.11
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	greg	2.29	int
101	greg	2.25	gmtval( /* convert GMT date line to UTC */
102			time_t *tloc,
103	greg	2.31	const char *s
104	schorsch	2.22	)
105	greg	2.11	{
106	greg	2.25	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	greg	2.11	}
123
124
125	greg	2.29	void
126	greg	2.25	fputdate( /* write out the given time value (local & GMT) */
127	schorsch	2.22	time_t tv,
128			FILE *fp
129			)
130	greg	2.11	{
131	greg	2.25	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	greg	2.11	}
144
145
146	greg	2.29	void
147	schorsch	2.22	fputnow( /* write out the current time */
148			FILE *fp
149			)
150	greg	2.11	{
151			time_t tv;
152			time(&tv);
153			fputdate(tv, fp);
154			}
155
156
157	greg	2.29	void
158	schorsch	2.22	printargs( /* print arguments to a file */
159			int ac,
160			char **av,
161			FILE *fp
162			)
163	greg	1.1	{
164			while (ac-- > 0) {
165	greg	2.11	fputword(*av++, fp);
166			fputc(ac ? ' ' : '\n', fp);
167	greg	1.1	}
168			}
169
170
171	greg	2.29	int
172	schorsch	2.22	formatval( /* get format value (return true if format) */
173	greg	2.32	char fmt[MAXFMTLEN],
174	greg	2.31	const char *s
175	schorsch	2.22	)
176	greg	1.2	{
177	greg	2.25	const char *cp = FMTSTR;
178	greg	2.32	char *r = fmt;
179	greg	2.4
180			while (cp) if (cp++ != *s++) return(0);
181	greg	1.3	while (isspace(*s)) s++;
182	greg	2.4	if (!*s) return(0);
183			if (r == NULL) return(1);
184	greg	2.5	do
185			r++ = s++;
186	greg	2.32	while (s && !isspace(s) && r-fmt < MAXFMTLEN-1);
187	greg	1.2	*r = '\0';
188	greg	2.4	return(1);
189	greg	1.2	}
190
191
192	greg	2.29	void
193	schorsch	2.22	fputformat( /* put out a format value */
194	greg	2.31	const char *s,
195	schorsch	2.22	FILE *fp
196			)
197	greg	1.2	{
198			fputs(FMTSTR, fp);
199			fputs(s, fp);
200			putc('\n', fp);
201			}
202
203
204	greg	2.29	int
205	schorsch	2.22	getheader( /* get header from file */
206			FILE *fp,
207			gethfunc *f,
208			void *p
209			)
210	greg	1.1	{
211	greg	2.30	int rtotal = 0;
212	greg	1.1	char buf[MAXLINE];
213
214			for ( ; ; ) {
215	greg	2.30	int rval = 0;
216	greg	1.1	buf[MAXLINE-2] = '\n';
217	greg	2.3	if (fgets(buf, MAXLINE, fp) == NULL)
218	greg	1.1	return(-1);
219	greg	2.28	if (buf[buf[0]=='\r'] == '\n')
220	greg	2.30	return(rtotal);
221	greg	1.1	if (buf[MAXLINE-2] != '\n') {
222			ungetc(buf[MAXLINE-2], fp); /* prevent false end */
223			buf[MAXLINE-2] = '\0';
224			}
225	greg	2.30	if (f != NULL && (rval = (*f)(buf, p)) < 0)
226	gwlarson	2.10	return(-1);
227	greg	2.30	rtotal += rval;
228	greg	1.1	}
229			}
230
231
232	greg	1.2	struct check {
233			FILE *fp;
234	greg	2.32	char fs[MAXFMTLEN];
235	greg	1.2	};
236	greg	1.1
237	greg	1.2
238	greg	2.11	static int
239	schorsch	2.22	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	greg	2.11	return(0);
249	greg	1.1	}
250
251
252	greg	2.29	int
253	schorsch	2.22	globmatch( /* check for match of s against pattern p */
254	greg	2.31	const char *p,
255			const char *s
256	schorsch	2.22	)
257	greg	1.3	{
258	greg	2.11	int setmatch;
259	greg	1.3
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	greg	2.28	if ( (p[1]=='?') \| (p[1]==*s) &&
270	greg	2.6	globmatch(p+1,s) )
271	greg	1.3	return(1);
272			while (*s++);
273			return(0);
274	greg	2.11	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	greg	2.28	setmatch += (p[-1] <= s && s <= p[1]);
283	greg	2.11	if (!*++p)
284			break;
285			} else
286	greg	2.28	setmatch += (p == s);
287	greg	2.11	}
288			if (!setmatch)
289			return(0);
290			s++;
291			break;
292	greg	1.3	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	greg	1.4	* error reading the header. If fmt is empty, then -1 is returned
311	greg	1.3	* 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	greg	2.7	* 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	greg	1.3	* The input header (minus any format lines) is copied to fout
317			* if fout is not NULL.
318			*/
319
320	greg	2.29	int
321	schorsch	2.22	checkheader(
322			FILE *fin,
323	greg	2.32	char fmt[MAXFMTLEN],
324	schorsch	2.22	FILE *fout
325			)
326	greg	1.1	{
327	greg	1.2	struct check cdat;
328	greg	2.25	char *cp;
329	greg	1.2
330			cdat.fp = fout;
331			cdat.fs[0] = '\0';
332	schorsch	2.22	if (getheader(fin, mycheck, &cdat) < 0)
333	greg	1.3	return(-1);
334	greg	2.6	if (!cdat.fs[0])
335			return(0);
336	greg	2.7	for (cp = fmt; cp; cp++) / check for globbing */
337	schorsch	2.20	if ((cp == '?') \| (cp == '*')) {
338	greg	2.7	if (globmatch(fmt, cdat.fs)) {
339			strcpy(fmt, cdat.fs);
340			return(1);
341			} else
342			return(-1);
343	schorsch	2.19	}
344	greg	2.7	return(strcmp(fmt, cdat.fs) ? -1 : 1); /* literal match */
345	greg	1.1	}