From ddbb295ab5bf203fcb00512a802956746e0a0709 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Laheurte?= <jerome@jeromelaheurte.net>
Date: Sun, 13 Sep 2020 13:46:44 +0200
Subject: [PATCH 1/3] Don't set MTU on socket

---
 l2cap_con.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/l2cap_con.c b/l2cap_con.c
index aa09dbb..0fc6e93 100644
--- a/l2cap_con.c
+++ b/l2cap_con.c
@@ -154,34 +154,14 @@ int acl_send_data (const char *bdaddr_dst, unsigned short cid, const unsigned ch
   return ret;
 }
 
-#define L2CAP_MTU 1024
-
 static void l2cap_setsockopt(int fd)
 {
-  struct l2cap_options l2o;
-  socklen_t len = sizeof(l2o);
-
   int opt = L2CAP_LM_MASTER;
   if (setsockopt(fd, SOL_L2CAP, L2CAP_LM, &opt, sizeof(opt)) < 0)
   {
     perror("setsockopt L2CAP_LM");
   }
 
-  memset(&l2o, 0, sizeof(l2o));
-  if(getsockopt(fd, SOL_L2CAP, L2CAP_OPTIONS, &l2o, &len) < 0)
-  {
-    perror("getsockopt L2CAP_OPTIONS");
-  }
-  else
-  {
-    l2o.omtu = L2CAP_MTU;
-    l2o.imtu = L2CAP_MTU;
-    if(setsockopt(fd, SOL_L2CAP, L2CAP_OPTIONS, &l2o, sizeof(l2o)) < 0)
-    {
-      perror("setsockopt L2CAP_OPTIONS");
-    }
-  }
-
   /*if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
   {
     perror("fcntl O_NONBLOCK");

From ae837b63464aa8b759db99137bb6edac394b14e6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Laheurte?= <jerome@jeromelaheurte.net>
Date: Sun, 27 Dec 2020 13:07:59 +0100
Subject: [PATCH 2/3] Add gitignore

---
 .gitignore | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b4454dc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+l2cap_proxy
+

From 75fac26dd456e5249dc2f2fa4915b5a451ae5c2c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Laheurte?= <jerome@jeromelaheurte.net>
Date: Fri, 3 Sep 2021 15:23:50 +0200
Subject: [PATCH 3/3] Add command-line arguments parsing

---
 README.md     |  2 +-
 l2cap_proxy.c | 81 +++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 73 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index ccaecfe..0f1e0b7 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ Run the proxy
 ```
 sudo service bluetooth stop  
 sudo hciconfig hci<X> up pscan  
-sudo ./l2cap_proxy <master-bdaddr> <dongle-bdaddr> <device-class>  
+sudo ./l2cap_proxy -h <master-bdaddr> [-d <dongle-bdaddr>] [-c <device-class>]
 ```
 ```
 <X>: the device number (type hciconfig to list the available adapters)  
diff --git a/l2cap_proxy.c b/l2cap_proxy.c
index c6cc9cf..7e2a881 100644
--- a/l2cap_proxy.c
+++ b/l2cap_proxy.c
@@ -103,6 +103,14 @@ static void close_fd(struct pollfd* pfd)
   pfd->fd = -1;
 }
 
+void usage()
+{
+  printf("Usage: l2cap_proxy [options] <host address>\n");
+  printf("Options:\n");
+  printf("  -d <addr>, --dongle <addr>      Dongle address\n");
+  printf("  -c <class>, --class <class>     Device class\n");
+}
+
 int main(int argc, char *argv[])
 {
   char* master = NULL;
@@ -120,6 +128,12 @@ int main(int argc, char *argv[])
   char slave[sizeof("00:00:00:00:00:00")+1] = {};
   unsigned short cid[CID_MAX_INDEX][PSM_MAX_INDEX];
 
+  enum {
+    ARGSTATE_NONE,
+    ARGSTATE_DONGLEADDR,
+    ARGSTATE_DEVCLASS
+  } argstate = ARGSTATE_NONE;
+
   /*
    * Set highest priority & scheduler policy.
    */
@@ -132,18 +146,67 @@ int main(int argc, char *argv[])
 
   (void) signal(SIGINT, terminate);
 
-  /* Check args */
-  if (argc >= 1)
-    master = argv[1];
+  /* Parse command line args */
+  for (int i = 1; i < argc; ++i) {
+    switch (argstate) {
+      case ARGSTATE_NONE:
+        if (!strcmp(argv[i], "-d") || !strcmp(argv[i], "--dongle"))
+        {
+          argstate = ARGSTATE_DONGLEADDR;
+        }
+        else if (!strcmp(argv[i], "-c") || !strcmp(argv[i], "--class"))
+        {
+          argstate = ARGSTATE_DEVCLASS;
+        }
+        else
+        {
+          if (bachk(argv[i]) == -1)
+          {
+            fprintf(stderr, "Invalid host address \"%s\"\n", argv[i]);
+            usage();
+            return 1;
+          }
+          master = argv[i];
+        }
+        break;
+      case ARGSTATE_DONGLEADDR:
+        if (bachk(argv[i]) == -1)
+        {
+          fprintf(stderr, "Invalid dongle address \"%s\"\n", argv[i]);
+          usage();
+          return 1;
+        }
+        local = argv[i];
+        argstate = ARGSTATE_NONE;
+        break;
+      case ARGSTATE_DEVCLASS:
+        device_class = strtol(argv[i], NULL, 0);
+        argstate = ARGSTATE_NONE;
+        break;
+    }
+  }
 
-  if (argc >= 2)
-    local = argv[2];
+  switch (argstate) {
+    case ARGSTATE_NONE:
+      break;
+    case ARGSTATE_DONGLEADDR:
+      fprintf(stderr, "Missing argument to -d\n");
+      break;
+    case ARGSTATE_DEVCLASS:
+      fprintf(stderr, "Missing argument to -c\n");
+      break;
+  }
 
-  if (argc >= 3)
-    device_class = strtol(argv[3], NULL, 0);
+  if (argstate != ARGSTATE_NONE)
+  {
+    usage();
+    return 1;
+  }
 
-  if (!master || bachk(master) == -1 || (local && bachk(local) == -1)) {
-    printf("usage: %s <ps3-mac-address> <dongle-mac-address> <device-class>\n", *argv);
+  if (!master)
+  {
+    fprintf(stderr, "Missing host address\n");
+    usage();
     return 1;
   }