Enhancements to allow l2cap channel to use either AMP or BR/EDR

Enhancements to allow l2cap channel to use either AMP or BR/EDR

[Inga Stotland]

AMP vs BR/EDR preference for L2CAP channel can be configured as 
command line argument using new option "-J". Possible values: 
                 "require_br_edr", 
                 "prefer_amp", 
                 "prefer_br_edr"
If no preference indicated, the default is set to require BR/EDR. 

Additionally, this option can be changed during  runtime when L2CAP 
connection is up by entering the following keys from standard input:   
         "a", "A" - prefer AMP;
         "b", "B" - prefer BR/EDR;
         "r", "R" - require BR/EDR
This allows dynamic L2CAP channel move between BR/EDR and AMP.


--
Inga Stotland
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[PATCH 1/4] Constants for L2CAP and AMP extensions

[Inga Stotland]

---
 lib/l2cap.h |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/lib/l2cap.h b/lib/l2cap.h
index e59cfdd..2f1084c 100644
--- a/lib/l2cap.h
+++ b/lib/l2cap.h
@@ -35,6 +35,8 @@ extern "C" {
 /* L2CAP defaults */
 #define L2CAP_DEFAULT_MTU	672
 #define L2CAP_DEFAULT_FLUSH_TO	0xFFFF
+#define L2CAP_DEFAULT_TX_WINDOW	63
+#define L2CAP_DEFAULT_MAX_TX	3
 
 /* L2CAP socket address */
 struct sockaddr_l2 {
@@ -44,6 +46,12 @@ struct sockaddr_l2 {
 	unsigned short	l2_cid;
 };
 
+/* L2CAP fixed channel CIDs */
+#define L2CAP_SIGNAL_CHAN_CID		0x0001
+#define L2CAP_CONNECTIONLESS_CID	0x0002
+#define L2CAP_AMP_MGR_CID		0x0003
+#define L2CAP_AMP_TEST_CID		0x003F
+
 /* L2CAP socket options */
 #define L2CAP_OPTIONS	0x01
 struct l2cap_options {
@@ -69,6 +77,12 @@ struct l2cap_conninfo {
 #define L2CAP_LM_TRUSTED	0x0008
 #define L2CAP_LM_RELIABLE	0x0010
 #define L2CAP_LM_SECURE		0x0020
+#define L2CAP_LM_FLUSHABLE	0x0040
+
+#define L2CAP_AMP	0x04
+#define L2CAP_AMP_REQUIRE_BR_EDR	0x01
+#define L2CAP_AMP_PREFER_AMP		0x02
+#define L2CAP_AMP_PREFER_BR_EDR	0x03
 
 /* L2CAP command codes */
 #define L2CAP_COMMAND_REJ	0x01
-- 
1.7.2

--
Inga Stotland
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[PATCH 2/4] Use defines for the default values of txwin_size and max_transmit.

[Inga Stotland]

---
 test/l2test.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/test/l2test.c b/test/l2test.c
index 0bb46f3..361f80c 100644
--- a/test/l2test.c
+++ b/test/l2test.c
@@ -76,10 +76,10 @@ static int omtu = 0;
 static int fcs = 0x01;
 
 /* Default Transmission Window */
-static int txwin_size = 63;
+static int txwin_size = L2CAP_DEFAULT_TX_WINDOW;
 
-/* Default Max Transmission */
-static int max_transmit = 3;
+/* Default Max Transmission (number of retries per packet) */
+static int max_transmit = L2CAP_DEFAULT_MAX_TX;
 
 /* Default data size */
 static long data_size = -1;
@@ -1073,8 +1073,8 @@ static void usage(void)
 		"\t[-D milliseconds] delay after sending num frames (default = 0)\n"
 		"\t[-X mode] select retransmission/flow-control mode\n"
 		"\t[-F fcs] use CRC16 check (default = 1)\n"
-		"\t[-Q num] Max Transmit value (default = 3)\n"
-		"\t[-Z size] Transmission Window size (default = 63)\n"
+		"\t[-Q num] Max Transmit value (default = %d)\n"
+		"\t[-Z size] Transmission Window size (default = %d)\n"
 		"\t[-R] reliable mode\n"
 		"\t[-G] use connectionless channel (datagram)\n"
 		"\t[-U] use sock stream\n"
@@ -1082,7 +1082,8 @@ static void usage(void)
 		"\t[-E] request encryption\n"
 		"\t[-S] secure connection\n"
 		"\t[-M] become master\n"
-		"\t[-T] enable timestamps\n");
+		"\t[-T] enable timestamps\n",
+		L2CAP_DEFAULT_MAX_TX, L2CAP_DEFAULT_TX_WINDOW);
 }
 
 int main(int argc, char *argv[])
-- 
1.7.2

--
Inga Stotland
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[PATCH 3/4] Added command argument "-J" to indicate preference of using AMP vs BR/EDR.

[Inga Stotland]

Possible values: "require_br_edr", "prefer_amp", "prefer_br_edr"
---
 test/l2test.c |   34 +++++++++++++++++++++++++++++++++-
 1 files changed, 33 insertions(+), 1 deletions(-)

diff --git a/test/l2test.c b/test/l2test.c
index 361f80c..377c12e 100644
--- a/test/l2test.c
+++ b/test/l2test.c
@@ -81,6 +81,9 @@ static int txwin_size = L2CAP_DEFAULT_TX_WINDOW;
 /* Default Max Transmission (number of retries per packet) */
 static int max_transmit = L2CAP_DEFAULT_MAX_TX;
 
+/* Default AMP preference */
+static int amp_pref = L2CAP_AMP_REQUIRE_BR_EDR;
+
 /* Default data size */
 static long data_size = -1;
 static long buffer_size = 2048;
@@ -295,6 +298,14 @@ static int do_connect(char *svr)
 		goto error;
 	}
 
+	/* Set AMP preference */
+	if ((rfcmode == L2CAP_MODE_ERTM || rfcmode == L2CAP_MODE_STREAMING) &&
+		setsockopt(sk, SOL_L2CAP, L2CAP_AMP, &amp_pref, sizeof(amp_pref)) < 0) {
+		syslog(LOG_ERR, "Can't set L2CAP AMP preference: %s (%d)",
+							strerror(errno), errno);
+		goto error;
+	}
+
 	/* Get current options */
 	memset(&opts, 0, sizeof(opts));
 	optlen = sizeof(opts);
@@ -458,6 +469,14 @@ static void do_listen(void (*handler)(int sk))
 		/* Child */
 		close(sk);
 
+		/* Set AMP preference */
+		if ((rfcmode == L2CAP_MODE_ERTM || rfcmode == L2CAP_MODE_STREAMING) &&
+			setsockopt(nsk, SOL_L2CAP, L2CAP_AMP, &amp_pref, sizeof(amp_pref)) < 0) {
+			syslog(LOG_ERR, "Can't set L2CAP AMP preference: %s (%d)",
+				   strerror(errno), errno);
+			goto error;
+		}
+
 		/* Get current options */
 		memset(&opts, 0, sizeof(opts));
 		optlen = sizeof(opts);
@@ -1075,6 +1094,8 @@ static void usage(void)
 		"\t[-F fcs] use CRC16 check (default = 1)\n"
 		"\t[-Q num] Max Transmit value (default = %d)\n"
 		"\t[-Z size] Transmission Window size (default = %d)\n"
+		"\t[-J amp] declare amp preference\n"
+		"\t         (require_br_edr, prefer_amp, prefer_br_edr)\n"
 		"\t[-R] reliable mode\n"
 		"\t[-G] use connectionless channel (datagram)\n"
 		"\t[-U] use sock stream\n"
@@ -1093,7 +1114,7 @@ int main(int argc, char *argv[])
 
 	bacpy(&bdaddr, BDADDR_ANY);
 
-	while ((opt=getopt(argc,argv,"rdscuwmntqxyzpb:i:P:I:O:B:N:L:W:C:D:X:F:Q:Z:RUGAESMT")) != EOF) {
+	while ((opt=getopt(argc,argv,"rdscuwmntqxyzpb:i:P:I:O:B:N:L:W:C:D:X:F:Q:Z:J:RUGAESMT")) != EOF) {
 		switch(opt) {
 		case 'r':
 			mode = RECV;
@@ -1217,6 +1238,17 @@ int main(int argc, char *argv[])
 			fcs = atoi(optarg);
 			break;
 
+		case 'J':
+			if (strcasecmp(optarg, "require_br_edr") == 0)
+				amp_pref = L2CAP_AMP_REQUIRE_BR_EDR;
+			else if (strcasecmp(optarg, "prefer_amp") == 0)
+				amp_pref = L2CAP_AMP_PREFER_AMP;
+			else if (strcasecmp(optarg, "prefer_br_edr") == 0)
+				amp_pref = L2CAP_AMP_PREFER_BR_EDR;
+			else
+				perror("Bad AMP preference");
+			break;
+
 		case 'R':
 			reliable = 1;
 			break;
-- 
1.7.2

--
Inga Stotland
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: [PATCH 3/4] Added command argument "-J" to indicate preference of using AMP vs BR/EDR.

[Gustavo F. Padovan]

Hi Inga,

* Inga Stotland <ingas@codeaurora.org> [2010-07-30 11:30:25 -0700]:

> Possible values: "require_br_edr", "prefer_amp", "prefer_br_edr"
> ---
>  test/l2test.c |   34 +++++++++++++++++++++++++++++++++-
>  1 files changed, 33 insertions(+), 1 deletions(-)
	
I would prefer to review and merge the kernel bits first and then go to
the userspace stuff. Doing that we'll have more sure that the socket
options won't change.

-- 
Gustavo F. Padovan
http://padovan.org

Re: [PATCH 3/4] Added command argument "-J" to indicate preference of using AMP vs BR/EDR.

[ingas]

Hi Gustavo,

> Hi Inga,
>
> * Inga Stotland <ingas@codeaurora.org> [2010-07-30 11:30:25 -0700]:
>
>> Possible values: "require_br_edr", "prefer_amp", "prefer_br_edr"
>> ---
>>  test/l2test.c |   34 +++++++++++++++++++++++++++++++++-
>>  1 files changed, 33 insertions(+), 1 deletions(-)
>
> I would prefer to review and merge the kernel bits first and then go to
> the userspace stuff. Doing that we'll have more sure that the socket
> options won't change.
>
> --
> Gustavo F. Padovan
> http://padovan.org
> --

I don't disagree with you. The kernel bits are coming this week. we will
retest l2test again when kernel stuff is upstreamed. This is just a sample
of how we envision the socket options to control the use of AMP...

And anyway, it takes me up to five iterations to get the style right :)

Regards,

Inga


--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

[PATCH 4/4] Allow changing AMP vs BR/EDR preference from stdin when connection is up.

[Inga Stotland]

Use the following keys:

"a", "A" - prefer AMP;
"b", "B" - prefer BR/EDR;
"r", "R" - require BR/EDR
---
 test/l2test.c |   87 +++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 76 insertions(+), 11 deletions(-)

diff --git a/test/l2test.c b/test/l2test.c
index 377c12e..1f627a7 100644
--- a/test/l2test.c
+++ b/test/l2test.c
@@ -191,6 +191,46 @@ static void hexdump(unsigned char *s, unsigned long l)
 	}
 }
 
+static void do_keys(int sk)
+{
+	struct pollfd p;
+	int len;
+	char c;
+	int old_amp_pref = amp_pref;
+
+	p.fd = 0;
+	p.events = POLLIN;
+
+	if (poll(&p, 1, 0)) {
+		len = read(0, &c, 1);
+		if (len < 0)
+			return;
+
+		switch (c) {
+		case 'A':
+		case 'a':
+			amp_pref = L2CAP_AMP_PREFER_AMP;
+			break;
+		case 'B':
+		case 'b':
+			amp_pref = L2CAP_AMP_PREFER_BR_EDR;
+			break;
+		case 'R':
+		case 'r':
+			amp_pref = L2CAP_AMP_REQUIRE_BR_EDR;
+			break;
+		default:
+			return;
+		}
+
+		setsockopt(sk, SOL_L2CAP, L2CAP_AMP, &amp_pref, sizeof(amp_pref));
+		syslog(LOG_INFO, "AMP preference updated to %d (previously %d)",
+			amp_pref, old_amp_pref);
+	}
+
+	return;
+}
+
 static int do_connect(char *svr)
 {
 	struct sockaddr_l2 addr;
@@ -584,11 +624,17 @@ static void dump_mode(int sk)
 		fd_set rset;
 
 		FD_ZERO(&rset);
+		FD_SET(0, &rset);
 		FD_SET(sk, &rset);
 
 		if (select(sk + 1, &rset, NULL, NULL, NULL) < 0)
 			return;
 
+		if (FD_ISSET(0, &rset)) {
+			do_keys(sk);
+			continue;
+		}
+
 		if (!FD_ISSET(sk, &rset))
 			continue;
 
@@ -620,7 +666,7 @@ static void dump_mode(int sk)
 static void recv_mode(int sk)
 {
 	struct timeval tv_beg, tv_end, tv_diff;
-	struct pollfd p;
+	struct pollfd p[2];
 	char ts[30];
 	long total;
 	uint32_t seq;
@@ -643,8 +689,11 @@ static void recv_mode(int sk)
 
 	memset(ts, 0, sizeof(ts));
 
-	p.fd = sk;
-	p.events = POLLIN | POLLERR | POLLHUP;
+	p[0].fd = sk;
+	p[0].events = POLLIN | POLLERR | POLLHUP;
+
+	p[1].fd = 0;
+	p[1].events = POLLIN;
 
 	seq = 0;
 	while (1) {
@@ -655,13 +704,19 @@ static void recv_mode(int sk)
 			uint16_t l;
 			int i;
 
-			p.revents = 0;
-			if (poll(&p, 1, -1) <= 0)
+			p[0].revents = 0;
+			p[1].revents = 0;
+			if (poll(p, 2, -1) <= 0)
 				return;
 
-			if (p.revents & (POLLERR | POLLHUP))
+			if (p[0].revents & (POLLERR | POLLHUP))
 				return;
 
+			if (p[1].revents & POLLIN) {
+				do_keys(sk);
+				continue;
+			}
+
 			len = recv(sk, buf, data_size, 0);
 			if (len < 0) {
 				if (reliable && (errno == ECOMM)) {
@@ -780,6 +835,8 @@ static void do_send(int sk)
 
 			sent += len;
 			size -= len;
+
+			do_keys(sk);
 		}
 
 		if (num_frames && delay && count && !(seq % count))
@@ -831,19 +888,27 @@ static void reconnect_mode(char *svr)
 
 static void connect_mode(char *svr)
 {
-	struct pollfd p;
+	struct pollfd p[2];
 	int sk;
 
 	if ((sk = do_connect(svr)) < 0)
 		exit(1);
 
-	p.fd = sk;
-	p.events = POLLERR | POLLHUP;
+	p[0].fd = sk;
+	p[0].events = POLLERR | POLLHUP;
+
+	p[1].fd = 0;
+	p[1].events = POLLIN;
 
 	while (1) {
-		p.revents = 0;
-		if (poll(&p, 1, 500))
+		p[0].revents = 0;
+		p[1].revents = 0;
+		if (poll(p, 2, 500) < 0)
+			break;
+		if (p[0].revents & (POLLERR | POLLHUP))
 			break;
+		if (p[1].revents & POLLIN)
+			do_keys(sk);
 	}
 
 	syslog(LOG_INFO, "Disconnected");
-- 
1.7.2

--
Inga Stotland
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

Re: Enhancements to allow l2cap channel to use either AMP or BR/EDR

[David Vrabel]

Inga Stotland wrote:
> AMP vs BR/EDR preference for L2CAP channel can be configured as 
> command line argument using new option "-J". Possible values: 
>                  "require_br_edr", 
>                  "prefer_amp", 
>                  "prefer_br_edr"
> If no preference indicated, the default is set to require BR/EDR. 

I think an explicit channel move command and a channel move complete
event are what many applications/profiles will need to be able to use an
AMP effectively.

David
-- 
David Vrabel, Senior Software Engineer, Drivers
CSR, Churchill House, Cambridge Business Park,  Tel: +44 (0)1223 692562
Cowley Road, Cambridge, CB4 0WZ                 http://www.csr.com/


Member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom