add support for printing RFC 8300 Network Service Header (NSH)

ok deraadt@

1 files changed, 308 insertions, 0 deletions

diff --git a/usr.sbin/tcpdump/print-nsh.c b/usr.sbin/tcpdump/print-nsh.c
new file mode 100644
index 00000000000..f21fe690119
--- /dev/null
+++ b/usr.sbin/tcpdump/print-nsh.c
@@ -0,0 +1,308 @@
+/*	$OpenBSD: print-nsh.c,v 1.1 2019/12/03 01:43:33 dlg Exp $ */
+
+/*
+ * Copyright (c) 2019 David Gwynne <dlg@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * RFC 8300 Network Service Header (NSH)
+ */
+
+#include <sys/time.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "interface.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#ifndef roundup
+#define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))
+#endif
+
+#ifndef nitems
+#define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
+#endif
+
+struct nsh_header {
+	uint32_t	base;
+#define NSH_VER_SHIFT		30
+#define NSH_VER_MASK		(0x03 << NSH_VER_SHIFT)
+#define NSH_VER_0		0x0
+#define NSH_VER_RESERVED	(0x01 << NSH_VER_SHIFT)
+#define NSH_OAM_SHIFT		29
+#define NSH_OAM_MASK		(0x01 << NSH_OAM_SHIFT)
+#define NSH_TTL_SHIFT		22
+#define NSH_TTL_MASK		(0x3f << NSH_TTL_SHIFT)
+#define NSH_LEN_SHIFT		16
+#define NSH_LEN_MASK		(0x3f << NSH_LEN_SHIFT)
+#define NSH_LEN_FACTOR		4
+#define NSH_MDTYPE_SHIFT	8
+#define NSH_MDTYPE_MASK		(0x0f << NSH_MDTYPE_SHIFT)
+#define NSH_PROTO_SHIFT		0
+#define NSH_PROTO_MASK		(0xff << NSH_PROTO_SHIFT)
+
+	uint32_t	sp;
+#define NSH_SPI_SHIFT		8
+#define NSH_SPI_MASK		(0xffffff << NSH_SPI_SHIFT)
+#define NSH_SI_SHIFT		0
+#define NSH_SI_MASK		(0xff << NSH_SI_SHIFT)
+};
+
+#define NSH_PROTO_IPV4		0x01
+#define NSH_PROTO_IPV6		0x02
+#define NSH_PROTO_ETHERNET	0x03
+#define NSH_PROTO_NSH		0x04
+#define NSH_PROTO_MPLS		0x05
+#define NSH_PROTO_EXP1		0xfe	/* Experiment 1 */
+#define NSH_PROTO_EXP2		0xff	/* Experiment 2 */
+
+#define NSH_MDTYPE_RESERVED	0x0
+#define NSH_MDTYPE_1		0x1
+#define NSH_MDTYPE_2		0x2
+#define NSH_MDTYPE_EXP		0xf	/* Experimentation */
+
+struct nsh_context_header {
+	uint32_t	ch[4];
+};
+
+struct nsh_md_header {
+	uint16_t	class;
+	uint8_t		type;
+	uint8_t		len;
+#define NSH_MD_LEN_MASK		0x7f
+};
+
+static void	nsh_print_bytes(const void *, u_int);
+
+static void	nsh_print_mdtype1(const u_char *, u_int);
+static void	nsh_print_mdtype2(const u_char *, u_int);
+
+void
+nsh_print(const u_char *p, u_int length)
+{
+	struct nsh_header nsh;
+	uint32_t field, len, proto;
+	int l = snapend - p;
+
+	printf("NSH");
+
+	if (l < sizeof(nsh))
+		goto trunc;
+	if (length < sizeof(nsh)) {
+		printf(" encapsulation truncated");
+		return;
+	}
+
+	nsh.base = EXTRACT_32BITS(p);
+	nsh.sp = EXTRACT_32BITS(p + sizeof(nsh.base));
+
+	field = (nsh.base & NSH_VER_MASK) >> NSH_VER_SHIFT;
+	switch (field) {
+	case NSH_VER_0:
+		break;
+	case NSH_VER_RESERVED:
+		printf(" Reserved version");
+		return;
+	default:
+		printf(" Unknown version %u", field);
+		return;
+	}
+
+	field = (nsh.sp & NSH_SPI_MASK) >> NSH_SPI_SHIFT;
+	printf(" spi %u", field);
+	field = (nsh.sp & NSH_SI_MASK) >> NSH_SI_SHIFT;
+	printf(" si %u", field);
+
+	len = ((nsh.base & NSH_LEN_MASK) >> NSH_LEN_SHIFT) * NSH_LEN_FACTOR;
+	if (vflag > 1) {
+		field = (nsh.base & NSH_TTL_MASK) >> NSH_TTL_SHIFT;
+		printf(" (ttl %u, len %u)", field, len);
+	}
+
+	if (l < len)
+		goto trunc;
+	if (length < len) {
+		printf(" encapsulation truncated");
+		return;
+	}
+
+	p += sizeof(nsh);
+	l -= sizeof(nsh);
+	len -= sizeof(nsh);
+
+	field = (nsh.base & NSH_MDTYPE_MASK) >> NSH_MDTYPE_SHIFT;
+	switch (field) {
+	case NSH_MDTYPE_RESERVED:
+		printf(" md-type-reserved");
+		break;
+	case NSH_MDTYPE_1:
+		printf(" md1");
+		if (vflag)
+			nsh_print_mdtype1(p, len);
+		break;
+	case NSH_MDTYPE_2:
+		printf(" md2");
+		if (vflag)
+			nsh_print_mdtype2(p, len);
+		break;
+	case NSH_MDTYPE_EXP:
+		printf(" mdtype-experimentation");
+		break;
+	default:
+		printf(" mdtype-unknown-0x%02x", field);
+		break;
+	}
+
+	printf("%s", vflag ? "\n    " : ": ");
+
+	p += len;
+	l -= len;
+	length -= len;
+
+	proto = (nsh.base & NSH_PROTO_MASK) >> NSH_PROTO_SHIFT;
+
+	if (nsh.base & NSH_OAM_MASK)
+		printf("NSH OAM (proto 0x%0x, len %u)", proto, length);
+	else {
+		switch (field) {
+		case NSH_PROTO_IPV4:
+			ip_print(p, length);
+			return;
+		case NSH_PROTO_IPV6:
+			ip_print(p, length);
+			return;
+		case NSH_PROTO_ETHERNET:
+			ether_tryprint(p, length, 0);
+			return;
+		case NSH_PROTO_NSH:
+			nsh_print(p, length);
+			return;
+		case NSH_PROTO_MPLS:
+			mpls_print(p, length);
+			return;
+		case NSH_PROTO_EXP1:
+			printf("NSH Experiment 1");
+			break;
+		case NSH_PROTO_EXP2:
+			printf("NSH Experiment 2");
+			break;
+		default:
+			printf("nsh-unknown-proto-0x%02x", field);
+			break;
+		}
+	}
+
+	if (vflag)
+		default_print_unaligned(p, length);
+
+	return;
+trunc:
+	printf(" [|nsh]");
+}
+
+static void
+nsh_print_mdtype1(const u_char *p, u_int len)
+{
+	const struct nsh_context_header *ctx;
+	size_t i;
+
+	if (len != sizeof(*ctx))
+		printf("nsh-mdtype1-length-%u (not %zu)", len, sizeof(*ctx));
+
+	printf("\n\tcontext");
+
+	ctx = (const struct nsh_context_header *)p;
+	for (i = 0; i < nitems(ctx->ch); i++) {
+		printf(" ");
+		nsh_print_bytes(&ctx->ch[i], sizeof(ctx->ch[i]));
+	}
+}
+
+static void
+nsh_print_mdtype2(const u_char *p, u_int l)
+{
+	if (l == 0)
+		return;
+
+	do {
+		struct nsh_md_header h;
+		uint8_t len;
+
+		if (l < sizeof(h))
+			goto trunc;
+
+		memcpy(&h, p, sizeof(h));
+		p += sizeof(h);
+		l -= sizeof(h);
+
+		h.class = ntohs(h.class);
+		len = h.len & NSH_MD_LEN_MASK;
+		printf("\n\tmd class %u type %u", h.class, h.type);
+		if (len > 0) {
+			printf(" ");
+			nsh_print_bytes(p, len);
+		}
+
+		len = roundup(len, 4);
+		if (l < len)
+			goto trunc;
+
+		p += len;
+		l -= len;
+	} while (l > 0);
+
+	return;
+trunc:
+	printf("[|nsh md]");
+}
+
+static void
+nsh_print_bytes(const void *b, u_int l)
+{
+	const uint8_t *p = b;
+	u_int i;
+
+	for (i = 0; i < l; i++) {
+		int ch = p[i];
+#if 0
+		if (isprint(ch) && !isspace(ch))
+			putchar(ch);
+		else {
+			switch (ch) {
+			case '\\':
+				printf("\\\\");
+				break;
+			case '\0':
+				printf("\\0");
+				break;
+			default:
+				printf("\\x%02x", ch);
+				break;
+			}
+		}
+#else
+		printf("%02x", ch);
+#endif
+	}
+}