RFC1144: integration and unit-test

The previously pushed slhc implementation has been modified to compile
and function outside of the kernel. Also debug log messages were added
and datatypes ware matched. The implementation is now ready to be used

Change-Id: I7a638e88a43b3eb9d006751a03ef2570e36613f0

6 files changed, 372 insertions, 0 deletions

diff --git a/openbsc/tests/Makefile.am b/openbsc/tests/Makefile.am
index 7b145f789..2e342e0aa 100644
--- a/openbsc/tests/Makefile.am
+++ b/openbsc/tests/Makefile.am
@@ -11,6 +11,7 @@ SUBDIRS = \
 	mm_auth \
 	xid \
 	sndcp_xid \
+	slhc \
 	$(NULL)
 
 if BUILD_NAT
diff --git a/openbsc/tests/sgsn/Makefile.am b/openbsc/tests/sgsn/Makefile.am
index cf8810160..bab3f0ef1 100644
--- a/openbsc/tests/sgsn/Makefile.am
+++ b/openbsc/tests/sgsn/Makefile.am
@@ -58,6 +58,7 @@ sgsn_test_LDADD = \
 	$(top_builddir)/src/gprs/oap_messages.o \
         $(top_builddir)/src/gprs/gprs_llc_xid.o \
 	$(top_builddir)/src/gprs/gprs_sndcp_xid.o \
+        $(top_builddir)/src/gprs/slhc.o \
 	$(top_builddir)/src/libcommon/libcommon.a \
 	$(LIBOSMOABIS_LIBS) \
 	$(LIBOSMOCORE_LIBS) \
diff --git a/openbsc/tests/slhc/Makefile.am b/openbsc/tests/slhc/Makefile.am
new file mode 100644
index 000000000..32a3cc447
--- /dev/null
+++ b/openbsc/tests/slhc/Makefile.am
@@ -0,0 +1,15 @@
+AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include
+AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBCARES_CFLAGS)
+
+EXTRA_DIST = slhc_test.ok
+
+noinst_PROGRAMS = slhc_test
+
+slhc_test_SOURCES = slhc_test.c
+
+slhc_test_LDADD = \
+	$(top_builddir)/src/gprs/slhc.o \
+	$(top_builddir)/src/libcommon/libcommon.a \
+	$(LIBOSMOCORE_LIBS)
+
+
diff --git a/openbsc/tests/slhc/slhc_test.c b/openbsc/tests/slhc/slhc_test.c
new file mode 100644
index 000000000..59a54259d
--- /dev/null
+++ b/openbsc/tests/slhc/slhc_test.c
@@ -0,0 +1,298 @@
+/* Test SLHC/RFC1144 TCP/IP Header compression/decompression */
+
+/* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Philipp Maier
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <openbsc/slhc.h>
+#include <openbsc/debug.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/core/application.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <arpa/inet.h>
+
+/* Number of compression slots (S0-1) */
+#define SLOTS 8
+
+/* Maximum packet bytes to display */
+#define DISP_MAX_BYTES 100
+
+/* Sample packets to test with */
+#define PACKETS_LEN 6
+char *packets[] = {
+	"4510004046dd40004006a9a7c0a8646ec0a864640017ad8b81980100f3ac984d801800e32a1600000101080a000647de06d1bf5efffd18fffd20fffd23fffd27",
+	"4510005b46de40004006a98bc0a8646ec0a864640017ad8b8198010cf3ac984d801800e3867500000101080a000647df06d1bf61fffb03fffd1ffffd21fffe22fffb05fffa2001fff0fffa2301fff0fffa2701fff0fffa1801fff0",
+	"4510003746df40004006a9aec0a8646ec0a864640017ad8b81980133f3ac989f801800e35fd700000101080a000647e106d1bf63fffd01",
+	"4510003746e040004006a9adc0a8646ec0a864640017ad8b81980136f3ac98a2801800e35fd200000101080a000647e106d1bf64fffb01",
+	"4510007446e140004006a96fc0a8646ec0a864640017ad8b81980139f3ac98a5801800e37b9b00000101080a000647e206d1bf640d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a57656c6c636f6d6520746f20706f6c6c75780d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a0d0a",
+	"4510004246e240004006a9a0c0a8646ec0a864640017ad8b81980179f3ac98a5801800e3dab000000101080a000647ec06d1bf6f706f6c6c7578206c6f67696e3a20"
+};
+
+/* Compress a packet using Van Jacobson RFC1144 header compression */
+static int compress(uint8_t *data_o, uint8_t *data_i, int len,
+		    struct slcompress *comp)
+{
+	uint8_t *comp_ptr;	/* Not used */
+	int compr_len;
+
+	/* Create a working copy of the incoming data */
+	memcpy(data_o, data_i, len);
+
+	/* Run compressor */
+	compr_len = slhc_compress(comp, data_i, len, data_o, &comp_ptr, 0);
+	return compr_len;
+}
+
+/* Expand a packet using Van Jacobson RFC1144 header compression */
+static int expand(uint8_t *data_o, uint8_t *data_i, int len,
+		  struct slcompress *comp)
+{
+	int data_decompressed_len;
+
+	/* Create a working copy of the incoming data */
+	memcpy(data_o, data_i, len);
+
+	/* Handle an uncompressed packet (learn header information */
+	if ((data_i[0] & SL_TYPE_UNCOMPRESSED_TCP) == SL_TYPE_UNCOMPRESSED_TCP) {
+		data_o[0] &= 0x4F;
+		data_decompressed_len = slhc_remember(comp, data_o, len);
+		return data_decompressed_len;
+	}
+
+	/* Uncompress compressed packets */
+	else if (data_o[0] & SL_TYPE_COMPRESSED_TCP) {
+		data_decompressed_len = slhc_uncompress(comp, data_o, len);
+		return data_decompressed_len;
+	}
+
+	/* Regular or unknown packets will not be touched */
+	return len;
+}
+
+/* Calculate IP Header checksum */
+static uint16_t calc_ip_csum(uint8_t *data, int len)
+{
+	int i;
+	uint32_t accumulator = 0;
+	uint16_t *pointer = (uint16_t *) data;
+
+	for (i = len; i > 1; i -= 2) {
+		accumulator += *pointer;
+		pointer++;
+	}
+
+	if (len % 2)
+		accumulator += *pointer;
+
+	accumulator = (accumulator & 0xffff) + ((accumulator >> 16) & 0xffff);
+	accumulator += (accumulator >> 16) & 0xffff;
+	return (~accumulator);
+}
+
+/* Calculate TCP/IP checksum */
+static uint16_t calc_tcpip_csum(const void *ctx, uint8_t *packet, int len)
+{
+	uint8_t *buf;
+	uint16_t csum;
+
+	buf = talloc_zero_size(ctx, len);
+	memset(buf, 0, len);
+	memcpy(buf, packet + 12, 8);
+	buf[9] = packet[9];
+	buf[11] = (len - 20) & 0xFF;
+	buf[10] = (len - 20) >> 8 & 0xFF;
+	memcpy(buf + 12, packet + 20, len - 20);
+	csum = calc_ip_csum(buf, len - 20 + 12);
+	talloc_free(buf);
+	return csum;
+}
+
+/* Check TCP/IP packet */
+static void check_packet(const void *ctx, uint8_t *packet, int len)
+{
+	/* Check IP header */
+	OSMO_ASSERT(len > 20);
+	OSMO_ASSERT(calc_ip_csum(packet, 20) == 0);
+
+	/* Check TCP packet */
+	if (packet[9] != 0x06)
+		return;
+	OSMO_ASSERT(len > 40);
+	OSMO_ASSERT(calc_tcpip_csum(ctx, packet, len) == 0);
+}
+
+/* Strip TCP options from TCP/IP packet */
+static int strip_tcp_options(const void *ctx, uint8_t *packet, int len)
+{
+	uint8_t doff;
+	uint16_t csum;
+
+	/* Check if the packet can be handled here */
+	if (len < 37)
+		return len;
+	if (packet[9] != 0x06)
+		return len;
+
+	/* Strip TCP/IP options from packet */
+	doff = ((packet[32] >> 4) & 0x0F) * 4;
+	memmove(packet + 40, packet + doff + 20, len - 40 - (doff - 20));
+	len = len - (doff - 20);
+
+	/* Repair data offset (TCP header length) */
+	packet[32] &= 0x0F;
+	packet[32] |= 0x50;
+
+	/* Repair checksum */
+	packet[36] = 0;
+	packet[37] = 0;
+	csum = calc_tcpip_csum(ctx, packet, len);
+	packet[36] = csum & 0xFF;
+	packet[37] = csum >> 8 & 0xFF;
+
+	/* Repair total length */
+	packet[3] = len & 0xFF;
+	packet[2] = len >> 8 & 0xFF;
+
+	/* Repair IP header checksum */
+	packet[10] = 0;
+	packet[11] = 0;
+	csum = calc_ip_csum(packet, 20);
+	packet[10] = csum & 0xFF;
+	packet[11] = csum >> 8 & 0xFF;
+	printf("csum=%04x\n", csum);
+
+	return len;
+}
+
+/* Compress / Decompress packets */
+static void test_slhc(const void *ctx)
+{
+	char packet_ascii[2048];
+	int i;
+
+	struct slcompress *comp;
+	uint8_t packet[1024];
+	int packet_len;
+	uint8_t packet_compr[1024];
+	int packet_compr_len;
+	uint8_t packet_decompr[1024];
+	int packet_decompr_len;
+
+	printf("Allocating compression state...\n");
+	comp = slhc_init(ctx, SLOTS, SLOTS);
+	OSMO_ASSERT(comp);
+
+	for(i=0;i<PACKETS_LEN;i++) {
+		/* Read input file */
+		memset(packet_ascii, 0, sizeof(packet_ascii));
+		memset(packet, 0, sizeof(packet));
+		memset(packet_compr, 0, sizeof(packet_compr));
+		memset(packet_decompr, 0, sizeof(packet_decompr));
+		strcpy(packet_ascii,packets[i]);
+
+		packet_len =
+		    osmo_hexparse(packet_ascii, packet, sizeof(packet));
+		check_packet(ctx, packet, packet_len);
+		packet_len = strip_tcp_options(ctx, packet, packet_len);
+		check_packet(ctx, packet, packet_len);
+
+		/* Run compression/decompression algorithm */
+		printf("Compressing...\n");
+		packet_compr_len =
+		    compress(packet_compr, packet, packet_len, comp);
+		printf("Decompressing...\n");
+		packet_decompr_len =
+		    expand(packet_decompr, packet_compr, packet_compr_len,
+			   comp);
+		OSMO_ASSERT(packet_decompr_len == packet_len);
+		check_packet(ctx,packet_decompr,packet_decompr_len);
+
+		/* Display results */
+		printf("Results:\n");
+		if (packet_compr_len > DISP_MAX_BYTES)
+			packet_compr_len = DISP_MAX_BYTES;
+		if (packet_len > DISP_MAX_BYTES)
+			packet_len = DISP_MAX_BYTES;
+		if (packet_decompr_len > DISP_MAX_BYTES)
+			packet_decompr_len = DISP_MAX_BYTES;
+		printf("Original Packet:    (%i bytes) %s\n", packet_len,
+		       osmo_hexdump_nospc(packet, packet_len));
+		printf("DecompressedPacket: (%i bytes) %s\n",
+		       packet_decompr_len, osmo_hexdump_nospc(packet_decompr,
+							      packet_decompr_len));
+		printf("CompressedPacket:   (%i bytes) %s\n", packet_compr_len,
+		       osmo_hexdump_nospc(packet_compr, packet_compr_len));
+		slhc_o_status(comp);
+		slhc_o_status(comp);
+
+		printf("\n");
+	}
+
+	printf("Freeing compression state...\n");
+	slhc_free(comp);
+	printf("\n");
+}
+
+static struct log_info_cat gprs_categories[] = {
+	[DSNDCP] = {
+		    .name = "DSNDCP",
+		    .description =
+		    "GPRS Sub-Network Dependent Control Protocol (SNDCP)",
+		    .enabled = 1,.loglevel = LOGL_DEBUG,
+		    },
+	[DSLHC] = {
+		   .name = "DSLHC",
+		   .description =
+		   "Van Jacobson RFC1144 TCP/IP header compression (SLHC)",
+		   .enabled = 1,.loglevel = LOGL_DEBUG,
+		   }
+};
+
+static struct log_info info = {
+	.cat = gprs_categories,
+	.num_cat = ARRAY_SIZE(gprs_categories),
+};
+
+int main(int argc, char **argv)
+{
+	void *ctx;
+
+	osmo_init_logging(&info);
+
+	ctx = talloc_named_const(NULL, 0, "slhc_ctx");
+
+	test_slhc(ctx);
+
+	printf("Done\n");
+
+	talloc_report_full(ctx, stderr);
+	OSMO_ASSERT(talloc_total_blocks(ctx) == 1);
+	return 0;
+}
+
+/* stubs */
+struct osmo_prim_hdr;
+int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
+{
+	abort();
+}
diff --git a/openbsc/tests/slhc/slhc_test.ok b/openbsc/tests/slhc/slhc_test.ok
new file mode 100644
index 000000000..636241dba
--- /dev/null
+++ b/openbsc/tests/slhc/slhc_test.ok
@@ -0,0 +1,52 @@
+Allocating compression state...
+csum=b3a9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (52 bytes) 4510003446dd40004006a9b3c0a8646ec0a864640017ad8b81980100f3ac984d501800e371410000fffd18fffd20fffd23fffd27
+DecompressedPacket: (52 bytes) 4510003446dd40004006a9b3c0a8646ec0a864640017ad8b81980100f3ac984d501800e371410000fffd18fffd20fffd23fffd27
+CompressedPacket:   (52 bytes) 7510003446dd40004000a9b3c0a8646ec0a864640017ad8b81980100f3ac984d501800e371410000fffd18fffd20fffd23fffd27
+
+csum=97a9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (79 bytes) 4510004f46de40004006a997c0a8646ec0a864640017ad8b8198010cf3ac984d501800e3cda40000fffb03fffd1ffffd21fffe22fffb05fffa2001fff0fffa2301fff0fffa2701fff0fffa1801fff0
+DecompressedPacket: (79 bytes) 4510004f46de40004006a997c0a8646ec0a864640017ad8b8198010cf3ac984d501800e3cda40000fffb03fffd1ffffd21fffe22fffb05fffa2001fff0fffa2301fff0fffa2701fff0fffa1801fff0
+CompressedPacket:   (43 bytes) df00cda4fffb03fffd1ffffd21fffe22fffb05fffa2001fff0fffa2301fff0fffa2701fff0fffa1801fff0
+
+csum=baa9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (43 bytes) 4510002b46df40004006a9bac0a8646ec0a864640017ad8b81980133f3ac989f501800e3a70a0000fffd01
+DecompressedPacket: (43 bytes) 4510002b46df40004006a9bac0a8646ec0a864640017ad8b81980133f3ac989f501800e3a70a0000fffd01
+CompressedPacket:   (9 bytes) dc00a70a5227fffd01
+
+csum=b9a9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (43 bytes) 4510002b46e040004006a9b9c0a8646ec0a864640017ad8b81980136f3ac98a2501800e3a7060000fffb01
+DecompressedPacket: (43 bytes) 4510002b46e040004006a9b9c0a8646ec0a864640017ad8b81980136f3ac98a2501800e3a7060000fffb01
+CompressedPacket:   (7 bytes) db00a706fffb01
+
+csum=7ba9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (100 bytes) 4510006846e140004006a97bc0a8646ec0a864640017ad8b81980139f3ac98a5501800e3c2d000000d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a57656c6c636f6d6520746f20706f6c6c75780d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d
+DecompressedPacket: (100 bytes) 4510006846e140004006a97bc0a8646ec0a864640017ad8b81980139f3ac98a5501800e3c2d000000d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a57656c6c636f6d6520746f20706f6c6c75780d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d
+CompressedPacket:   (68 bytes) db00c2d00d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a57656c6c636f6d6520746f20706f6c6c75780d0a2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d2d0d0a0d0a
+
+csum=aca9
+Compressing...
+Decompressing...
+Results:
+Original Packet:    (54 bytes) 4510003646e240004006a9acc0a8646ec0a864640017ad8b81980179f3ac98a5501800e321fb0000706f6c6c7578206c6f67696e3a20
+DecompressedPacket: (54 bytes) 4510003646e240004006a9acc0a8646ec0a864640017ad8b81980179f3ac98a5501800e321fb0000706f6c6c7578206c6f67696e3a20
+CompressedPacket:   (18 bytes) df0021fb706f6c6c7578206c6f67696e3a20
+
+Freeing compression state...
+
+Done
diff --git a/openbsc/tests/testsuite.at b/openbsc/tests/testsuite.at
index 85a81d6d5..5f37b8e22 100644
--- a/openbsc/tests/testsuite.at
+++ b/openbsc/tests/testsuite.at
@@ -136,3 +136,8 @@ cat $abs_srcdir/sndcp_xid/sndcp_xid_test.ok > expout
 AT_CHECK([$abs_top_builddir/tests/sndcp_xid/sndcp_xid_test], [], [expout], [ignore])
 AT_CLEANUP
 
+AT_SETUP([slhc])
+AT_KEYWORDS([slhc])
+cat $abs_srcdir/slhc/slhc_test.ok > expout
+AT_CHECK([$abs_top_builddir/tests/slhc/slhc_test], [], [expout], [ignore])
+AT_CLEANUP