/*
- * This module implements decoding of AHCP (Ad Hoc Configuration Protocol) based
- * on draft-chroboczek-ahcp-00 and source code of ahcpd-0.53.
- *
- *
* Copyright (c) 2013 The TCPDUMP project
* All rights reserved.
*
* POSSIBILITY OF SUCH DAMAGE.
*/
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+/* \summary: Ad Hoc Configuration Protocol (AHCP) printer */
+
+/* Based on draft-chroboczek-ahcp-00 and source code of ahcpd-0.53 */
+
+#include <config.h>
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
-#include "interface.h"
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"
-static const char *corrupt_str = "(corrupt)";
-static const char *trunc_str = "[|ahcp]";
#define AHCP_MAGIC_NUMBER 43
#define AHCP_VERSION_1 1
{ 0, NULL }
};
-static int
-ahcp_time_print(const u_char *cp, const u_char *ep) {
+static void
+ahcp_time_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
time_t t;
- struct tm *tm;
- char buf[BUFSIZE];
-
- if (cp + 4 != ep)
- goto corrupt;
- TCHECK2(*cp, 4);
- t = EXTRACT_32BITS(cp);
- if (NULL == (tm = gmtime(&t)))
- printf(": gmtime() error");
- else if (0 == strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm))
- printf(": strftime() error");
- else
- printf(": %s UTC", buf);
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+ char buf[sizeof("-yyyyyyyyyy-mm-dd hh:mm:ss UTC")];
+
+ if (len != 4)
+ goto invalid;
+ t = GET_BE_U_4(cp);
+ ND_PRINT(": %s",
+ nd_format_time(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S UTC",
+ gmtime(&t)));
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-static int
-ahcp_seconds_print(const u_char *cp, const u_char *ep) {
- if (cp + 4 != ep)
- goto corrupt;
- TCHECK2(*cp, 4);
- printf(": %us", EXTRACT_32BITS(cp));
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+static void
+ahcp_seconds_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
+ if (len != 4)
+ goto invalid;
+ ND_PRINT(": %us", GET_BE_U_4(cp));
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-static int
-ahcp_ipv6_addresses_print(const u_char *cp, const u_char *ep) {
+static void
+ahcp_ipv6_addresses_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
const char *sep = ": ";
- while (cp < ep) {
- if (cp + 16 > ep)
- goto corrupt;
- TCHECK2(*cp, 16);
- printf("%s%s", sep,
-#ifdef INET6
- ip6addr_string(cp)
-#else
- "(compiled w/o IPv6)"
-#endif /* INET6 */
- );
+ while (len) {
+ if (len < 16)
+ goto invalid;
+ ND_PRINT("%s%s", sep, GET_IP6ADDR_STRING(cp));
cp += 16;
+ len -= 16;
sep = ", ";
}
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-static int
-ahcp_ipv4_addresses_print(const u_char *cp, const u_char *ep) {
+static void
+ahcp_ipv4_addresses_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
const char *sep = ": ";
- while (cp < ep) {
- if (cp + 4 > ep)
- goto corrupt;
- TCHECK2(*cp, 4);
- printf("%s%s", sep, ipaddr_string(cp));
+ while (len) {
+ if (len < 4)
+ goto invalid;
+ ND_PRINT("%s%s", sep, GET_IPADDR_STRING(cp));
cp += 4;
+ len -= 4;
sep = ", ";
}
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-static int
-ahcp_ipv6_prefixes_print(const u_char *cp, const u_char *ep) {
+static void
+ahcp_ipv6_prefixes_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
const char *sep = ": ";
- while (cp < ep) {
- if (cp + 17 > ep)
- goto corrupt;
- TCHECK2(*cp, 17);
- printf("%s%s/%u", sep,
-#ifdef INET6
- ip6addr_string(cp),
-#else
- "(compiled w/o IPv6)",
-#endif /* INET6 */
- *(cp + 16));
+ while (len) {
+ if (len < 17)
+ goto invalid;
+ ND_PRINT("%s%s/%u", sep, GET_IP6ADDR_STRING(cp), GET_U_1(cp + 16));
cp += 17;
+ len -= 17;
sep = ", ";
}
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-static int
-ahcp_ipv4_prefixes_print(const u_char *cp, const u_char *ep) {
+static void
+ahcp_ipv4_prefixes_print(netdissect_options *ndo,
+ const u_char *cp, uint8_t len)
+{
const char *sep = ": ";
- while (cp < ep) {
- if (cp + 5 > ep)
- goto corrupt;
- TCHECK2(*cp, 5);
- printf("%s%s/%u", sep, ipaddr_string(cp), *(cp + 4));
+ while (len) {
+ if (len < 5)
+ goto invalid;
+ ND_PRINT("%s%s/%u", sep, GET_IPADDR_STRING(cp), GET_U_1(cp + 4));
cp += 5;
+ len -= 5;
sep = ", ";
}
- return 0;
-
-corrupt:
- printf(": %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return 0;
-trunc:
- printf(" %s", trunc_str);
- return -1;
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-/* Data decoders signal truncated data with -1. */
-static int
-(* const data_decoders[AHCP1_OPT_MAX + 1])(const u_char *, const u_char *) = {
+static void
+(* const data_decoders[AHCP1_OPT_MAX + 1])(netdissect_options *, const u_char *, uint8_t) = {
/* [AHCP1_OPT_PAD] = */ NULL,
/* [AHCP1_OPT_MANDATORY] = */ NULL,
/* [AHCP1_OPT_ORIGIN_TIME] = */ ahcp_time_print,
};
static void
-ahcp1_options_print(const u_char *cp, const u_char *ep) {
- uint8_t option_no, option_len;
+ahcp1_options_print(netdissect_options *ndo,
+ const u_char *cp, uint16_t len)
+{
+ while (len) {
+ uint8_t option_no, option_len;
- while (cp < ep) {
/* Option no */
- TCHECK2(*cp, 1);
- option_no = *cp;
+ option_no = GET_U_1(cp);
cp += 1;
- printf("\n\t %s", tok2str(ahcp1_opt_str, "Unknown-%u", option_no));
+ len -= 1;
+ ND_PRINT("\n\t %s", tok2str(ahcp1_opt_str, "Unknown-%u", option_no));
if (option_no == AHCP1_OPT_PAD || option_no == AHCP1_OPT_MANDATORY)
continue;
/* Length */
- if (cp + 1 > ep)
- goto corrupt;
- TCHECK2(*cp, 1);
- option_len = *cp;
+ if (!len)
+ goto invalid;
+ option_len = GET_U_1(cp);
cp += 1;
- if (cp + option_len > ep)
- goto corrupt;
+ len -= 1;
+ if (option_len > len)
+ goto invalid;
/* Value */
if (option_no <= AHCP1_OPT_MAX && data_decoders[option_no] != NULL) {
- if (data_decoders[option_no](cp, cp + option_len) < 0)
- break; /* truncated and already marked up */
+ data_decoders[option_no](ndo, cp, option_len);
} else {
- printf(" (Length %u)", option_len);
- TCHECK2(*cp, option_len);
+ ND_PRINT(" (Length %u)", option_len);
+ ND_TCHECK_LEN(cp, option_len);
}
cp += option_len;
+ len -= option_len;
}
return;
-corrupt:
- printf(" %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return;
-trunc:
- printf(" %s", trunc_str);
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
static void
-ahcp1_body_print(const u_char *cp, const u_char *ep) {
+ahcp1_body_print(netdissect_options *ndo,
+ const u_char *cp, u_int len)
+{
uint8_t type, mbz;
uint16_t body_len;
- if (cp + AHCP1_BODY_MIN_LEN > ep)
- goto corrupt;
+ if (len < AHCP1_BODY_MIN_LEN)
+ goto invalid;
/* Type */
- TCHECK2(*cp, 1);
- type = *cp;
+ type = GET_U_1(cp);
cp += 1;
+ len -= 1;
/* MBZ */
- TCHECK2(*cp, 1);
- mbz = *cp;
+ mbz = GET_U_1(cp);
cp += 1;
+ len -= 1;
/* Length */
- TCHECK2(*cp, 2);
- body_len = EXTRACT_16BITS(cp);
+ body_len = GET_BE_U_2(cp);
cp += 2;
+ len -= 2;
- if (vflag) {
- printf("\n\t%s", tok2str(ahcp1_msg_str, "Unknown-%u", type));
+ if (ndo->ndo_vflag) {
+ ND_PRINT("\n\t%s", tok2str(ahcp1_msg_str, "Unknown-%u", type));
if (mbz != 0)
- printf(", MBZ %u", mbz);
- printf(", Length %u", body_len);
+ ND_PRINT(", MBZ %u", mbz);
+ ND_PRINT(", Length %u", body_len);
}
- if (cp + body_len > ep)
- goto corrupt;
+ if (body_len > len)
+ goto invalid;
/* Options */
- if (vflag >= 2)
- ahcp1_options_print(cp, cp + body_len); /* not ep (ignore extra data) */
+ /* Here use "body_len", not "len" (ignore any extra data). */
+ if (ndo->ndo_vflag >= 2)
+ ahcp1_options_print(ndo, cp, body_len);
else
- TCHECK2(*cp, body_len);
+ ND_TCHECK_LEN(cp, body_len);
return;
-corrupt:
- printf(" %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return;
-trunc:
- printf(" %s", trunc_str);
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
+
}
void
-ahcp_print(const u_char *cp, const u_int len) {
- const u_char *ep = cp + len;
+ahcp_print(netdissect_options *ndo,
+ const u_char *cp, u_int len)
+{
uint8_t version;
- printf("AHCP");
+ ndo->ndo_protocol = "ahcp";
+ nd_print_protocol_caps(ndo);
if (len < 2)
- goto corrupt;
+ goto invalid;
/* Magic */
- TCHECK2(*cp, 1);
- if (*cp != AHCP_MAGIC_NUMBER)
- goto corrupt;
+ if (GET_U_1(cp) != AHCP_MAGIC_NUMBER)
+ goto invalid;
cp += 1;
+ len -= 1;
/* Version */
- TCHECK2(*cp, 1);
- version = *cp;
+ version = GET_U_1(cp);
cp += 1;
+ len -= 1;
switch (version) {
case AHCP_VERSION_1: {
- printf(" Version 1");
- if (len < AHCP1_HEADER_FIX_LEN)
- goto corrupt;
- if (!vflag) {
- TCHECK2(*cp, AHCP1_HEADER_FIX_LEN - 2);
+ ND_PRINT(" Version 1");
+ if (len < AHCP1_HEADER_FIX_LEN - 2)
+ goto invalid;
+ if (!ndo->ndo_vflag) {
+ ND_TCHECK_LEN(cp, AHCP1_HEADER_FIX_LEN - 2);
cp += AHCP1_HEADER_FIX_LEN - 2;
+ len -= AHCP1_HEADER_FIX_LEN - 2;
} else {
/* Hopcount */
- TCHECK2(*cp, 1);
- printf("\n\tHopcount %u", *cp);
+ ND_PRINT("\n\tHopcount %u", GET_U_1(cp));
cp += 1;
+ len -= 1;
/* Original Hopcount */
- TCHECK2(*cp, 1);
- printf(", Original Hopcount %u", *cp);
+ ND_PRINT(", Original Hopcount %u", GET_U_1(cp));
cp += 1;
+ len -= 1;
/* Nonce */
- TCHECK2(*cp, 4);
- printf(", Nonce 0x%08x", EXTRACT_32BITS(cp));
+ ND_PRINT(", Nonce 0x%08x", GET_BE_U_4(cp));
cp += 4;
+ len -= 4;
/* Source Id */
- TCHECK2(*cp, 8);
- printf(", Source Id %s", linkaddr_string(cp, 0, 8));
+ ND_PRINT(", Source Id %s", GET_LINKADDR_STRING(cp, LINKADDR_OTHER, 8));
cp += 8;
+ len -= 8;
/* Destination Id */
- TCHECK2(*cp, 8);
- printf(", Destination Id %s", linkaddr_string(cp, 0, 8));
+ ND_PRINT(", Destination Id %s", GET_LINKADDR_STRING(cp, LINKADDR_OTHER, 8));
cp += 8;
+ len -= 8;
}
/* Body */
- ahcp1_body_print(cp, ep);
+ ahcp1_body_print(ndo, cp, len);
break;
}
default:
- printf(" Version %u (unknown)", version);
+ ND_PRINT(" Version %u (unknown)", version);
+ ND_TCHECK_LEN(cp, len);
break;
}
return;
-corrupt:
- printf(" %s", corrupt_str);
- TCHECK2(*cp, ep - cp);
- return;
-trunc:
- printf(" %s", trunc_str);
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cp, len);
}
-
projects / tcpdump / blobdiff