2 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23 * txtproto_print() derived from original code by Hannes Gredler
24 * (hannes@gredler.at):
26 * Redistribution and use in source and binary forms, with or without
27 * modification, are permitted provided that: (1) source code
28 * distributions retain the above copyright notice and this paragraph
29 * in its entirety, and (2) distributions including binary code include
30 * the above copyright notice and this paragraph in its entirety in
31 * the documentation or other materials provided with the distribution.
32 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
33 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
34 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
35 * FOR A PARTICULAR PURPOSE.
42 #include "netdissect-stdinc.h"
54 #include "netdissect-ctype.h"
56 #include "netdissect.h"
58 #include "ascii_strcasecmp.h"
59 #include "timeval-operations.h"
61 #define TOKBUFSIZE 128
63 enum date_flag
{ WITHOUT_DATE
= 0, WITH_DATE
= 1 };
64 enum time_flag
{ UTC_TIME
= 0, LOCAL_TIME
= 1 };
67 * Print out a character, filtering out the non-printable ones
70 fn_print_char(netdissect_options
*ndo
, u_char c
)
76 if (!ND_ASCII_ISPRINT(c
)) {
77 c
^= 0x40; /* DEL to ?, others to alpha */
84 * Print a null-terminated string, filtering out non-printable characters.
85 * DON'T USE IT with a pointer on the packet buffer because there is no
86 * truncation check. For this use, see the nd_printX() functions below.
89 fn_print_str(netdissect_options
*ndo
, const u_char
*s
)
92 fn_print_char(ndo
, *s
);
98 * Print out a null-terminated filename (or other ASCII string) from
99 * a fixed-length field in the packet buffer, or from what remains of
102 * n is the length of the fixed-length field, or the number of bytes
103 * remaining in the packet based on its on-the-network length.
105 * If ep is non-null, it should point just past the last captured byte
106 * of the packet, e.g. ndo->ndo_snapend. If ep is NULL, we assume no
107 * truncation check, other than the checks of the field length/remaining
108 * packet data length, is needed.
110 * Return the number of bytes of string processed, including the
111 * terminating null, if not truncated; as the terminating null is
112 * included in the count, and as there must be a terminating null,
113 * this will always be non-zero. Return 0 if truncated.
116 nd_printztn(netdissect_options
*ndo
,
117 const u_char
*s
, u_int n
, const u_char
*ep
)
124 if (n
== 0 || (ep
!= NULL
&& s
>= ep
)) {
126 * Truncated. This includes "no null before we
127 * got to the end of the fixed-length buffer or
128 * the end of the packet".
130 * XXX - BOOTP says "null-terminated", which
131 * means the maximum length of the string, in
132 * bytes, is 1 less than the size of the buffer,
133 * as there must always be a terminating null.
147 fn_print_char(ndo
, c
);
153 * Print out a counted filename (or other ASCII string), part of
155 * If ep is NULL, assume no truncation check is needed.
156 * Return true if truncated.
157 * Stop at ep (if given) or after n bytes, whichever is first.
160 nd_printn(netdissect_options
*ndo
,
161 const u_char
*s
, u_int n
, const u_char
*ep
)
165 while (n
> 0 && (ep
== NULL
|| s
< ep
)) {
169 fn_print_char(ndo
, c
);
171 return (n
== 0) ? 0 : 1;
175 * Print a counted filename (or other ASCII string), part of
176 * the packet buffer, filtering out non-printable characters.
177 * Stop if truncated (via GET_U_1/longjmp) or after n bytes,
178 * whichever is first.
179 * The suffix comes from: j:longJmp, n:after N bytes.
182 nd_printjn(netdissect_options
*ndo
, const u_char
*s
, u_int n
)
185 fn_print_char(ndo
, GET_U_1(s
));
192 * Print a null-padded filename (or other ASCII string), part of
193 * the packet buffer, filtering out non-printable characters.
194 * Stop if truncated (via GET_U_1/longjmp) or after n bytes or before
195 * the null char, whichever occurs first.
196 * The suffix comes from: j:longJmp, n:after N bytes, p:null-Padded.
199 nd_printjnp(netdissect_options
*ndo
, const u_char
*s
, u_int n
)
207 fn_print_char(ndo
, c
);
214 * Print the timestamp .FRAC part (Microseconds/nanoseconds)
217 ts_frac_print(netdissect_options
*ndo
, long usec
)
219 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
220 switch (ndo
->ndo_tstamp_precision
) {
222 case PCAP_TSTAMP_PRECISION_MICRO
:
223 ND_PRINT(".%06u", (unsigned)usec
);
226 case PCAP_TSTAMP_PRECISION_NANO
:
227 ND_PRINT(".%09u", (unsigned)usec
);
231 ND_PRINT(".{unknown}");
235 ND_PRINT(".%06u", (unsigned)usec
);
240 * Print the timestamp as [YY:MM:DD] HH:MM:SS.FRAC.
241 * if time_flag == LOCAL_TIME print local time else UTC/GMT time
242 * if date_flag == WITH_DATE print YY:MM:DD before HH:MM:SS.FRAC
245 ts_date_hmsfrac_print(netdissect_options
*ndo
, long sec
, long usec
,
246 enum date_flag date_flag
, enum time_flag time_flag
)
252 if ((unsigned)sec
& 0x80000000) {
253 ND_PRINT("[Error converting time]");
257 if (time_flag
== LOCAL_TIME
)
258 tm
= localtime(&Time
);
263 ND_PRINT("[Error converting time]");
266 if (date_flag
== WITH_DATE
)
267 strftime(timestr
, sizeof(timestr
), "%Y-%m-%d %H:%M:%S", tm
);
269 strftime(timestr
, sizeof(timestr
), "%H:%M:%S", tm
);
270 ND_PRINT("%s", timestr
);
272 ts_frac_print(ndo
, usec
);
276 * Print the timestamp - Unix timeval style, as SECS.FRAC.
279 ts_unix_print(netdissect_options
*ndo
, long sec
, long usec
)
281 if ((unsigned)sec
& 0x80000000) {
282 ND_PRINT("[Error converting time]");
286 ND_PRINT("%u", (unsigned)sec
);
287 ts_frac_print(ndo
, usec
);
291 * Print the timestamp
294 ts_print(netdissect_options
*ndo
,
295 const struct timeval
*tvp
)
297 static struct timeval tv_ref
;
298 struct timeval tv_result
;
302 switch (ndo
->ndo_tflag
) {
304 case 0: /* Default */
305 ts_date_hmsfrac_print(ndo
, tvp
->tv_sec
, tvp
->tv_usec
,
306 WITHOUT_DATE
, LOCAL_TIME
);
310 case 1: /* No time stamp */
313 case 2: /* Unix timeval style */
314 ts_unix_print(ndo
, tvp
->tv_sec
, tvp
->tv_usec
);
318 case 3: /* Microseconds/nanoseconds since previous packet */
319 case 5: /* Microseconds/nanoseconds since first packet */
320 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
321 switch (ndo
->ndo_tstamp_precision
) {
322 case PCAP_TSTAMP_PRECISION_MICRO
:
325 case PCAP_TSTAMP_PRECISION_NANO
:
335 if (!(netdissect_timevalisset(&tv_ref
)))
336 tv_ref
= *tvp
; /* set timestamp for first packet */
338 negative_offset
= netdissect_timevalcmp(tvp
, &tv_ref
, <);
340 netdissect_timevalsub(&tv_ref
, tvp
, &tv_result
, nano_prec
);
342 netdissect_timevalsub(tvp
, &tv_ref
, &tv_result
, nano_prec
);
344 ND_PRINT((negative_offset
? "-" : " "));
345 ts_date_hmsfrac_print(ndo
, tv_result
.tv_sec
, tv_result
.tv_usec
,
346 WITHOUT_DATE
, UTC_TIME
);
349 if (ndo
->ndo_tflag
== 3)
350 tv_ref
= *tvp
; /* set timestamp for previous packet */
353 case 4: /* Date + Default */
354 ts_date_hmsfrac_print(ndo
, tvp
->tv_sec
, tvp
->tv_usec
,
355 WITH_DATE
, LOCAL_TIME
);
362 * Print an unsigned relative number of seconds (e.g. hold time, prune timer)
363 * in the form 5m1s. This does no truncation, so 32230861 seconds
364 * is represented as 1y1w1d1h1m1s.
367 unsigned_relts_print(netdissect_options
*ndo
,
370 static const char *lengths
[] = {"y", "w", "d", "h", "m", "s"};
371 static const u_int seconds
[] = {31536000, 604800, 86400, 3600, 60, 1};
372 const char **l
= lengths
;
373 const u_int
*s
= seconds
;
381 ND_PRINT("%u%s", secs
/ *s
, *l
);
382 secs
-= (secs
/ *s
) * *s
;
390 * Print a signed relative number of seconds (e.g. hold time, prune timer)
391 * in the form 5m1s. This does no truncation, so 32230861 seconds
392 * is represented as 1y1w1d1h1m1s.
395 signed_relts_print(netdissect_options
*ndo
,
400 if (secs
== INT32_MIN
) {
402 * -2^31; you can't fit its absolute value into
403 * a 32-bit signed integer.
405 * Just directly pass said absolute value to
406 * unsigned_relts_print() directly.
408 * (XXX - does ISO C guarantee that -(-2^n),
409 * when calculated and cast to an n-bit unsigned
410 * integer type, will have the value 2^n?)
412 unsigned_relts_print(ndo
, 2147483648U);
415 * We now know -secs will fit into an int32_t;
416 * negate it and pass that to unsigned_relts_print().
418 unsigned_relts_print(ndo
, -secs
);
422 unsigned_relts_print(ndo
, secs
);
425 /* Print the truncated string */
426 void nd_print_trunc(netdissect_options
*ndo
)
428 ND_PRINT(" [|%s]", ndo
->ndo_protocol
);
431 /* Print the protocol name */
432 void nd_print_protocol(netdissect_options
*ndo
)
434 ND_PRINT("%s", ndo
->ndo_protocol
);
437 /* Print the protocol name in caps (uppercases) */
438 void nd_print_protocol_caps(netdissect_options
*ndo
)
441 for (p
= ndo
->ndo_protocol
; *p
!= '\0'; p
++)
442 ND_PRINT("%c", ND_ASCII_TOUPPER(*p
));
445 /* Print the invalid string */
446 void nd_print_invalid(netdissect_options
*ndo
)
448 ND_PRINT(" (invalid)");
452 * this is a generic routine for printing unknown data;
453 * we pass on the linefeed plus indentation string to
454 * get a proper output - returns 0 on error
458 print_unknown_data(netdissect_options
*ndo
, const u_char
*cp
,
459 const char *indent
, u_int len
)
461 if (!ND_TTEST_LEN(cp
, 0)) {
462 ND_PRINT("%sDissector error: %s() called with pointer past end of packet",
466 hex_print(ndo
, indent
, cp
, ND_MIN(len
, ND_BYTES_AVAILABLE_AFTER(cp
)));
467 return(1); /* everything is ok */
471 * Convert a token value to a string; use "fmt" if not found.
474 tok2strbuf(const struct tok
*lp
, const char *fmt
,
475 u_int v
, char *buf
, size_t bufsize
)
478 while (lp
->s
!= NULL
) {
487 (void)snprintf(buf
, bufsize
, fmt
, v
);
488 return (const char *)buf
;
492 * Convert a token value to a string; use "fmt" if not found.
493 * Uses tok2strbuf() on one of four local static buffers of size TOKBUFSIZE
494 * in round-robin fashion.
497 tok2str(const struct tok
*lp
, const char *fmt
,
500 static char buf
[4][TOKBUFSIZE
];
506 return tok2strbuf(lp
, fmt
, v
, ret
, sizeof(buf
[0]));
510 * Convert a bit token value to a string; use "fmt" if not found.
511 * this is useful for parsing bitfields, the output strings are separated
512 * if the s field is positive.
514 * A token matches iff it has one or more bits set and every bit that is set
515 * in the token is set in v. Consequently, a 0 token never matches.
518 bittok2str_internal(const struct tok
*lp
, const char *fmt
,
519 u_int v
, const char *sep
)
521 static char buf
[1024+1]; /* our string buffer */
523 size_t space_left
= sizeof(buf
), string_size
;
524 const char * sepstr
= "";
526 while (lp
!= NULL
&& lp
->s
!= NULL
) {
527 if (lp
->v
&& (v
& lp
->v
) == lp
->v
) {
528 /* ok we have found something */
530 return (buf
); /* only enough room left for NUL, if that */
531 string_size
= strlcpy(bufp
, sepstr
, space_left
);
532 if (string_size
>= space_left
)
533 return (buf
); /* we ran out of room */
535 space_left
-= string_size
;
537 return (buf
); /* only enough room left for NUL, if that */
538 string_size
= strlcpy(bufp
, lp
->s
, space_left
);
539 if (string_size
>= space_left
)
540 return (buf
); /* we ran out of room */
542 space_left
-= string_size
;
549 /* bummer - lets print the "unknown" message as advised in the fmt string if we got one */
550 (void)snprintf(buf
, sizeof(buf
), fmt
== NULL
? "#%08x" : fmt
, v
);
555 * Convert a bit token value to a string; use "fmt" if not found.
556 * this is useful for parsing bitfields, the output strings are not separated.
559 bittok2str_nosep(const struct tok
*lp
, const char *fmt
,
562 return (bittok2str_internal(lp
, fmt
, v
, ""));
566 * Convert a bit token value to a string; use "fmt" if not found.
567 * this is useful for parsing bitfields, the output strings are comma separated.
570 bittok2str(const struct tok
*lp
, const char *fmt
,
573 return (bittok2str_internal(lp
, fmt
, v
, ", "));
577 * Convert a value to a string using an array; the macro
578 * tok2strary() in <netdissect.h> is the public interface to
579 * this function and ensures that the second argument is
580 * correct for bounds-checking.
583 tok2strary_internal(const char **lp
, int n
, const char *fmt
,
586 static char buf
[TOKBUFSIZE
];
588 if (v
>= 0 && v
< n
&& lp
[v
] != NULL
)
592 (void)snprintf(buf
, sizeof(buf
), fmt
, v
);
597 uint2tokary_internal(const struct uint_tokary dict
[], const size_t size
,
601 /* Try a direct lookup before the full scan. */
602 if (val
< size
&& dict
[val
].uintval
== val
)
603 return dict
[val
].tokary
; /* OK if NULL */
604 for (i
= 0; i
< size
; i
++)
605 if (dict
[i
].uintval
== val
)
606 return dict
[i
].tokary
; /* OK if NULL */
611 * Convert a 32-bit netmask to prefixlen if possible
612 * the function returns the prefix-len; if plen == -1
613 * then conversion was not possible;
617 mask2plen(uint32_t mask
)
619 const uint32_t bitmasks
[33] = {
621 0x80000000, 0xc0000000, 0xe0000000, 0xf0000000,
622 0xf8000000, 0xfc000000, 0xfe000000, 0xff000000,
623 0xff800000, 0xffc00000, 0xffe00000, 0xfff00000,
624 0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000,
625 0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000,
626 0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00,
627 0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0,
628 0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff
632 /* let's see if we can transform the mask into a prefixlen */
633 while (prefix_len
>= 0) {
634 if (bitmasks
[prefix_len
] == mask
)
642 mask62plen(const u_char
*mask
)
644 u_char bitmasks
[9] = {
646 0x80, 0xc0, 0xe0, 0xf0,
647 0xf8, 0xfc, 0xfe, 0xff
652 for (byte
= 0; byte
< 16; byte
++) {
655 for (bits
= 0; bits
< (sizeof (bitmasks
) / sizeof (bitmasks
[0])); bits
++) {
656 if (mask
[byte
] == bitmasks
[bits
]) {
662 if (mask
[byte
] != 0xff)
669 * Routine to print out information for text-based protocols such as FTP,
670 * HTTP, SMTP, RTSP, SIP, ....
672 #define MAX_TOKEN 128
675 * Fetch a token from a packet, starting at the specified index,
676 * and return the length of the token.
678 * Returns 0 on error; yes, this is indistinguishable from an empty
679 * token, but an "empty token" isn't a valid token - it just means
680 * either a space character at the beginning of the line (this
681 * includes a blank line) or no more tokens remaining on the line.
684 fetch_token(netdissect_options
*ndo
, const u_char
*pptr
, u_int idx
, u_int len
,
685 u_char
*tbuf
, size_t tbuflen
)
690 for (; idx
< len
; idx
++) {
691 if (!ND_TTEST_1(pptr
+ idx
)) {
692 /* ran past end of captured data */
695 c
= GET_U_1(pptr
+ idx
);
696 if (!ND_ISASCII(c
)) {
697 /* not an ASCII character */
700 if (c
== ' ' || c
== '\t' || c
== '\r' || c
== '\n') {
704 if (!ND_ASCII_ISPRINT(c
)) {
705 /* not part of a command token or response code */
708 if (toklen
+ 2 > tbuflen
) {
709 /* no room for this character and terminating '\0' */
722 * Skip past any white space after the token, until we see
723 * an end-of-line (CR or LF).
725 for (; idx
< len
; idx
++) {
726 if (!ND_TTEST_1(pptr
+ idx
)) {
727 /* ran past end of captured data */
730 c
= GET_U_1(pptr
+ idx
);
731 if (c
== '\r' || c
== '\n') {
735 if (!ND_ASCII_ISPRINT(c
)) {
736 /* not a printable ASCII character */
739 if (c
!= ' ' && c
!= '\t' && c
!= '\r' && c
!= '\n') {
740 /* beginning of next token */
748 * Scan a buffer looking for a line ending - LF or CR-LF.
749 * Return the index of the character after the line ending or 0 if
750 * we encounter a non-ASCII or non-printable character or don't find
754 print_txt_line(netdissect_options
*ndo
, const char *prefix
,
755 const u_char
*pptr
, u_int idx
, u_int len
)
763 c
= GET_U_1(pptr
+ idx
);
766 * LF without CR; end of line.
767 * Skip the LF and print the line, with the
768 * exception of the LF.
770 linelen
= idx
- startidx
;
773 } else if (c
== '\r') {
775 if ((idx
+1) >= len
) {
776 /* not in this packet */
779 if (GET_U_1(pptr
+ idx
+ 1) == '\n') {
781 * CR-LF; end of line.
782 * Skip the CR-LF and print the line, with
783 * the exception of the CR-LF.
785 linelen
= idx
- startidx
;
791 * CR followed by something else; treat this
792 * as if it were binary data, and don't print
796 } else if (!ND_ASCII_ISPRINT(c
) && c
!= '\t') {
798 * Not a printable ASCII character and not a tab;
799 * treat this as if it were binary data, and
808 * All printable ASCII, but no line ending after that point
809 * in the buffer; treat this as if it were truncated.
811 linelen
= idx
- startidx
;
812 ND_PRINT("%s%.*s", prefix
, (int)linelen
, pptr
+ startidx
);
817 ND_PRINT("%s%.*s", prefix
, (int)linelen
, pptr
+ startidx
);
821 /* Assign needed before calling txtproto_print(): ndo->ndo_protocol = "proto" */
823 txtproto_print(netdissect_options
*ndo
, const u_char
*pptr
, u_int len
,
824 const char **cmds
, u_int flags
)
827 u_char token
[MAX_TOKEN
+1];
833 * This protocol has more than just request and
834 * response lines; see whether this looks like a
835 * request or response and, if so, print it and,
836 * in verbose mode, print everything after it.
838 * This is for HTTP-like protocols, where we
839 * want to print requests and responses, but
840 * don't want to print continuations of request
841 * or response bodies in packets that don't
842 * contain the request or response line.
844 idx
= fetch_token(ndo
, pptr
, 0, len
, token
, sizeof(token
));
846 /* Is this a valid request name? */
847 while ((cmd
= *cmds
++) != NULL
) {
848 if (ascii_strcasecmp((const char *)token
, cmd
) == 0) {
856 * No - is this a valid response code (3 digits)?
858 * Is this token the response code, or is the next
859 * token the response code?
861 if (flags
& RESP_CODE_SECOND_TOKEN
) {
863 * Next token - get it.
865 idx
= fetch_token(ndo
, pptr
, idx
, len
, token
,
869 if (ND_ASCII_ISDIGIT(token
[0]) && ND_ASCII_ISDIGIT(token
[1]) &&
870 ND_ASCII_ISDIGIT(token
[2]) && token
[3] == '\0') {
880 * 1) This protocol has only request and response lines
881 * (e.g., FTP, where all the data goes over a different
882 * connection); assume the payload is a request or
887 * 2) This protocol is just text, so that we should
888 * always, at minimum, print the first line and,
889 * in verbose mode, print all lines.
894 nd_print_protocol_caps(ndo
);
898 * In non-verbose mode, just print the protocol, followed
901 * In verbose mode, print lines as text until we run out
902 * of characters or see something that's not a
903 * printable-ASCII line.
905 if (ndo
->ndo_vflag
) {
907 * We're going to print all the text lines in the
908 * request or response; just print the length
909 * on the first line of the output.
911 ND_PRINT(", length: %u", len
);
913 idx
< len
&& (eol
= print_txt_line(ndo
, "\n\t", pptr
, idx
, len
)) != 0;
918 * Just print the first text line.
920 print_txt_line(ndo
, ": ", pptr
, 0, len
);
925 #if (defined(__i386__) || defined(_M_IX86) || defined(__X86__) || defined(__x86_64__) || defined(_M_X64)) || \
926 (defined(__arm__) || defined(_M_ARM) || defined(__aarch64__)) || \
927 (defined(__m68k__) && (!defined(__mc68000__) && !defined(__mc68010__))) || \
928 (defined(__ppc__) || defined(__ppc64__) || defined(_M_PPC) || defined(_ARCH_PPC) || defined(_ARCH_PPC64)) || \
929 (defined(__s390__) || defined(__s390x__) || defined(__zarch__)) || \
932 * The procesor natively handles unaligned loads, so just use memcpy()
933 * and memcmp(), to enable those optimizations.
935 * XXX - are those all the x86 tests we need?
936 * XXX - do we need to worry about ARMv1 through ARMv5, which didn't
937 * support unaligned loads, and, if so, do we need to worry about all
938 * of them, or just some of them, e.g. ARMv5?
939 * XXX - are those the only 68k tests we need not to generated
940 * unaligned accesses if the target is the 68000 or 68010?
941 * XXX - are there any tests we don't need, because some definitions are for
942 * compilers that also predefine the GCC symbols?
943 * XXX - do we need to test for both 32-bit and 64-bit versions of those
944 * architectures in all cases?
948 * The processor doesn't natively handle unaligned loads,
949 * and the compiler might "helpfully" optimize memcpy()
950 * and memcmp(), when handed pointers that would normally
951 * be properly aligned, into sequences that assume proper
954 * Do copies and compares of possibly-unaligned data by
955 * calling routines that wrap memcpy() and memcmp(), to
956 * prevent that optimization.
959 unaligned_memcpy(void *p
, const void *q
, size_t l
)
964 /* As with memcpy(), so with memcmp(). */
966 unaligned_memcmp(const void *p
, const void *q
, size_t l
)
968 return (memcmp(p
, q
, l
));