sockaddr: decode Bluetooth L2 CID values

* xlat/bluetooth_l2_cid.in: New file.
* sockaddr.c: Include xlat/bluetooth_l2_cid.h.
(print_bluetooth_l2_cid): New function.
(print_sockaddr_data_bt): Use it to decode struct sockaddr_l2.l2_cid
field.
* tests/net-sockaddr.c (check_l2): Update expected output.

Co-Authored-by: Dmitry V. Levin <[email protected]>

Author: esyr

sockaddr.c

@@ -55,6 +55,7 @@
 #include "xlat/af_packet_types.h"
 
 #include "xlat/bdaddr_types.h"
+#include "xlat/bluetooth_l2_cid.h"
 #include "xlat/bluetooth_l2_psm.h"
 #include "xlat/hci_channels.h"
 
@@ -306,6 +307,40 @@ print_bluetooth_l2_psm(const char *prefix, uint16_t psm)
 	tprints(")");
 }
 
+static void
+print_bluetooth_l2_cid(const char *prefix, uint16_t cid)
+{
+	const uint16_t cid_he = btohs(cid);
+	const char *cid_name = xlookup(bluetooth_l2_cid, cid_he);
+	const bool cid_str = cid_name || (cid_he >= L2CAP_CID_DYN_START);
+
+	tprintf("%shtobs(", prefix);
+
+	if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV || !cid_str)
+		tprintf("%#x", cid_he);
+
+	if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_RAW)
+		goto print_bluetooth_l2_cid_end;
+
+	if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE || !cid_str)
+		tprints(" /* ");
+
+	if (cid_name) {
+		tprints(cid_name);
+	} else if (cid_he >= L2CAP_CID_DYN_START) {
+		print_xlat(L2CAP_CID_DYN_START);
+		tprintf(" + %u", cid_he - L2CAP_CID_DYN_START);
+	} else {
+		tprints("L2CAP_CID_???");
+	}
+
+	if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE || !cid_str)
+		tprints(" */");
+
+print_bluetooth_l2_cid_end:
+	tprints(")");
+}
+
 static void
 print_sockaddr_data_bt(const void *const buf, const int addrlen)
 {
@@ -368,12 +403,12 @@ print_sockaddr_data_bt(const void *const buf, const int addrlen)
 		case sizeof(struct sockaddr_l2): {
 			const struct sockaddr_l2 *const l2 = buf;
 			print_bluetooth_l2_psm("l2_psm=", l2->l2_psm);
-			tprintf(", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
-				", l2_cid=htobs(%hu), l2_bdaddr_type=",
+			tprintf(", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x",
 				l2->l2_bdaddr.b[0], l2->l2_bdaddr.b[1],
 				l2->l2_bdaddr.b[2], l2->l2_bdaddr.b[3],
-				l2->l2_bdaddr.b[4], l2->l2_bdaddr.b[5],
-				btohs(l2->l2_cid));
+				l2->l2_bdaddr.b[4], l2->l2_bdaddr.b[5]);
+			print_bluetooth_l2_cid(", l2_cid=", l2->l2_cid);
+			tprints(", l2_bdaddr_type=");
 			printxval_index(bdaddr_types, l2->l2_bdaddr_type,
 					"BDADDR_???");
 			break;

tests/net-sockaddr.c

@@ -450,40 +450,44 @@ check_l2(void)
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_DYN_START + %hu)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
-	       ", l2_cid=htobs(%hu), l2_bdaddr_type=0xce /* BDADDR_??? */}"
+	       ", l2_cid=htobs(L2CAP_CID_DYN_START + %hu)"
+	       ", l2_bdaddr_type=0xce /* BDADDR_??? */}"
 	       ", %u) = %d EBADF (%m)\n", h_psm - 0x1001,
 	       c_l2.l2_bdaddr.b[0], c_l2.l2_bdaddr.b[1],
 	       c_l2.l2_bdaddr.b[2], c_l2.l2_bdaddr.b[3],
 	       c_l2.l2_bdaddr.b[4], c_l2.l2_bdaddr.b[5],
-	       h_cid, len, ret);
+	       h_cid - 0x40, len, ret);
 
 	c_l2.l2_psm = htobs(1);
+	c_l2.l2_cid = htobs(1);
 	c_l2.l2_bdaddr_type = BDADDR_LE_RANDOM;
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(L2CAP_PSM_SDP)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
-	       ", l2_cid=htobs(%hu), l2_bdaddr_type=BDADDR_LE_RANDOM}"
-	       ", %u) = %d EBADF (%m)\n",
+	       ", l2_cid=htobs(L2CAP_CID_SIGNALING)"
+	       ", l2_bdaddr_type=BDADDR_LE_RANDOM}, %u) = %d EBADF (%m)\n",
 	       c_l2.l2_bdaddr.b[0], c_l2.l2_bdaddr.b[1],
 	       c_l2.l2_bdaddr.b[2], c_l2.l2_bdaddr.b[3],
 	       c_l2.l2_bdaddr.b[4], c_l2.l2_bdaddr.b[5],
-	       h_cid, len, ret);
+	       len, ret);
 
 	c_l2.l2_psm = htobs(0xbad);
+	c_l2.l2_cid = htobs(8);
 	c_l2.l2_bdaddr_type = 3;
 	memcpy(l2, &c_l2, sizeof(c_l2));
 	ret = connect(-1, l2, len);
 	printf("connect(-1, {sa_family=AF_BLUETOOTH"
 	       ", l2_psm=htobs(0xbad /* L2CAP_PSM_??? */)"
 	       ", l2_bdaddr=%02x:%02x:%02x:%02x:%02x:%02x"
-	       ", l2_cid=htobs(%hu), l2_bdaddr_type=0x3 /* BDADDR_??? */}"
+	       ", l2_cid=htobs(0x8 /* L2CAP_CID_??? */)"
+	       ", l2_bdaddr_type=0x3 /* BDADDR_??? */}"
 	       ", %u) = %d EBADF (%m)\n",
 	       c_l2.l2_bdaddr.b[0], c_l2.l2_bdaddr.b[1],
 	       c_l2.l2_bdaddr.b[2], c_l2.l2_bdaddr.b[3],
 	       c_l2.l2_bdaddr.b[4], c_l2.l2_bdaddr.b[5],
-	       h_cid, len, ret);
+	       len, ret);
 }
 #endif
 

xlat/bluetooth_l2_cid.in

@@ -0,0 +1,11 @@
+/* sort -k2,2 */
+L2CAP_CID_SIGNALING	0x0001
+L2CAP_CID_CONN_LESS	0x0002
+L2CAP_CID_A2MP		0x0003
+L2CAP_CID_ATT		0x0004
+L2CAP_CID_LE_SIGNALING	0x0005
+L2CAP_CID_SMP		0x0006
+L2CAP_CID_SMP_BREDR	0x0007
+L2CAP_CID_DYN_START	0x0040
+L2CAP_CID_LE_DYN_END	0x007f
+L2CAP_CID_DYN_END	0xffff