[ipaccess] There is only one second magic number

* The second magic number is only a short and it is
  the same for all of my cases
* This also means that the first and second header
  are the same which means the unknown 8 byte are
  header and file size... and the 122 bytes are
  actually multiple strings (just all empty on the
  outermost SDP). Adding the strings left us with 120
  bytes so we have two bytes of unknown usage..
* This is now capable of parsing outer and inner SDP
  files and print their header.

1 files changed, 23 insertions, 36 deletions

diff --git a/openbsc/src/ipaccess/ipaccess-firmware.c b/openbsc/src/ipaccess/ipaccess-firmware.c
index d2afb5057..fcdc2e6f9 100644
--- a/openbsc/src/ipaccess/ipaccess-firmware.c
+++ b/openbsc/src/ipaccess/ipaccess-firmware.c
@@ -34,27 +34,22 @@
 
 struct sdp_firmware_start {
 	char magic[4];
-	char more_magic[4];
+	char more_magic[2];
+	u_int16_t more_more_magic;
 } __attribute__((packed));
 
 struct sdp_firmware {
 	u_int32_t header_length;
 	u_int32_t file_length;
 	char sw_part[20];
-	char text1[122];
-	u_int16_t part_length;
-	/* stuff i don't know */
-} __attribute__((packed));
-
-struct sdp_firmware_2 {
-	u_int8_t no_idea[8];
-	char text1[20];
-	char text2[64];
+	char text1[64];
 	char time[12];
 	char date[14];
-	char text3[10];
-	char text4[20];
-	u_int16_t some_length;
+	char text2[10];
+	char text3[20];
+	u_int8_t dummy[2];
+	u_int16_t part_length;
+	/* stuff i don't know */
 } __attribute__((packed));
 
 struct sdp_header_entry {
@@ -74,15 +69,12 @@ static_assert(sizeof(struct sdp_header_entry) == 138, right_entry);
 static_assert(sizeof(struct sdp_firmware_start) + sizeof(struct sdp_firmware) == 160, _right_header_length);
 
 /* more magic, the second "int" in the header */
-static char more_magic[] = { 0x10, 0x02, 0x00, 0x0 };
-static char more_magic_internal[] = { 0x10, 0x02, 0x20, 0x0 };
-
+static char more_magic[] = { 0x10, 0x02 };
 
 static void analyze_file(int fd, const unsigned int st_size, const unsigned int base_offset)
 {
 	struct sdp_firmware_start *firmware_start;
 	struct sdp_firmware *firmware_header = 0;
-	struct sdp_firmware_2 *firmware_2 = 0;
 	char buf[4096];
 	int rc, i;
 	unsigned int start_offset = 0;
@@ -100,7 +92,7 @@ static void analyze_file(int fd, const unsigned int st_size, const unsigned int
 	}
 
 	start_offset = sizeof(*firmware_start);
-	if (memcmp(firmware_start->more_magic, more_magic, 4) == 0) {
+	if (memcmp(firmware_start->more_magic, more_magic, 2) == 0) {
 		rc = read(fd, &buf[start_offset], sizeof(*firmware_header));
 		if (rc != sizeof(*firmware_header)) {
 			perror("Can not read header.");
@@ -108,20 +100,6 @@ static void analyze_file(int fd, const unsigned int st_size, const unsigned int
 		}
 		firmware_header = (struct sdp_firmware *) &buf[start_offset];
 		start_offset += sizeof(*firmware_header);
-	} else if (memcmp(firmware_start->more_magic, more_magic_internal, 4) == 0) {
-		rc = read(fd, &buf[start_offset], sizeof(*firmware_2));
-		if (rc != sizeof(*firmware_2)) {
-			perror("Can not read header version type 2.");
-			return;
-		}
-		firmware_2 = (struct sdp_firmware_2 *) &buf[start_offset];
-		start_offset += sizeof(*firmware_2);
-		printf("Firmware header 2\n");
-		printf("text1: %.64s\n", firmware_2->text1);
-		printf("time: %.12s\n", firmware_2->time);
-		printf("date: %.14s\n", firmware_2->date);
-		printf("text2: %.10s\n", firmware_2->text2);
-		printf("text3: %.20s\n", firmware_2->text3);
 	} else {
 		fprintf(stderr, "Wrong more magic. Got: 0x%x %x %x %x\n",
 			firmware_start->more_magic[0] & 0xff, firmware_start->more_magic[1] & 0xff,
@@ -134,18 +112,27 @@ static void analyze_file(int fd, const unsigned int st_size, const unsigned int
 		return;
 
 	printf("Printing header information:\n");
+	printf("more_more_magic: 0x%x\n", ntohs(firmware_start->more_more_magic));
 	printf("header_length: %u\n", ntohl(firmware_header->header_length));
 	printf("file_length: %u\n", ntohl(firmware_header->file_length));
 	printf("sw_part: %.20s\n", firmware_header->sw_part);
-	printf("text1: %.120s\n", firmware_header->text1);
-	printf("items: %u (rest %u)\n", ntohs(firmware_header->part_length) / PART_LENGTH,
-		ntohs(firmware_header->part_length) % PART_LENGTH);
-
+	printf("text1: %.64s\n", firmware_header->text1);
+	printf("time: %.12s\n", firmware_header->time);
+	printf("date: %.14s\n", firmware_header->date);
+	printf("text2: %.10s\n", firmware_header->text2);
+	printf("text3: %.20s\n", firmware_header->text3);
 	if (ntohl(firmware_header->file_length) != st_size) {
 		fprintf(stderr, "The filesize and the header do not match.\n");
 		return;
 	}
 
+	/* this semantic appears to be only the case for 0x0000 */
+	if (firmware_start->more_more_magic != 0)
+		return;
+
+	printf("items: %u (rest %u)\n", ntohs(firmware_header->part_length) / PART_LENGTH,
+		ntohs(firmware_header->part_length) % PART_LENGTH);
+
 	if (ntohs(firmware_header->part_length) % PART_LENGTH != 0) {
 		fprintf(stderr, "The part length seems to be wrong.\n");
 		return;