Re: [Bluez-devel] Bluetooth device name database

Re: [Bluez-devel] Bluetooth device name database

[Takashi Sasai]

[-- Attachment #1: Type: text/plain, Size: 653 bytes --]

Hi Max and David,

> >libbluetooth ? Do you mean that libbluetooth should provide a way to read
> >from the name database ? In that case, it should also provide methods to
> >access the link_key database (to remove a subscription), doesn't it ?
> Something like that.
> 
> >An other question : if an application (link key managment software) wants to
> >modify the link_key file, and hcid receives a connection at the same time...
> >Is there some kind of lock so that the link key file is always consistent ?
> Currently no. But writes to a file are almost guarantied to be atomic.

I wrote such a code before. How about this pache?

Regards,
Takashi


[-- Attachment #2: bluez-libs-2.0-rmkey.patch --]
[-- Type: application/octet-stream, Size: 4118 bytes --]

diff -uNr bluez-libs-2.0.orig/include/hci_lib.h bluez-libs-2.0/include/hci_lib.h
--- bluez-libs-2.0.orig/include/hci_lib.h	Mon Aug 26 08:55:00 2002
+++ bluez-libs-2.0/include/hci_lib.h	Thu Sep  5 11:10:41 2002
@@ -161,6 +161,10 @@
 	return (f->opcode == opcode);
 }
 
+/* for HCId */
+int remove_link_key(int dev_id, bdaddr_t *dba);
+int show_link_keys(void);
+
 #ifdef __cplusplus
 }
 #endif
diff -uNr bluez-libs-2.0.orig/src/hci.c bluez-libs-2.0/src/hci.c
--- bluez-libs-2.0.orig/src/hci.c	Mon Aug 26 08:55:00 2002
+++ bluez-libs-2.0/src/hci.c	Thu Sep  5 11:12:44 2002
@@ -47,6 +47,8 @@
 #include <hci.h>
 #include <hci_lib.h>
 
+#include <sys/file.h>
+
 typedef struct {
 	char  *str; unsigned int val;
 } hci_map;
@@ -1000,3 +1002,164 @@
 		return -1;
 	return 0;
 }
+
+/* for HCId */
+
+#define HCID_KEY_FILE    "/etc/bluetooth/link_key"
+
+struct link_key {
+        bdaddr_t sba;
+        bdaddr_t dba;
+        uint8_t  key[16];
+        uint8_t  type;
+        time_t   time;
+};
+
+/* Read exactly len bytes */
+static inline int read_n(int fd, void *buf, int len)
+{
+	register int t = 0, w;
+
+	while (len > 0) {
+		if ((w = read(fd, buf, len)) < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return -1;
+		}
+		if (!w)
+			return 0;
+		len -= w;
+		buf += w;
+		t += w;
+	}
+
+	return t;
+}
+
+/* Write exactly len bytes */
+static inline int write_n(int fd, void *buf, int len)
+{
+	register int t = 0, w;
+
+	while (len > 0) {
+		if ((w = write(fd, buf, len)) < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return -1;
+		}
+		if (!w)
+			return 0;
+		len -= w;
+		buf += w;
+		t += w;
+	}
+
+	return t;
+}
+
+int remove_link_key(int dev_id, bdaddr_t *dba)
+{
+  char sa[40], da[40];
+  bdaddr_t sba;
+  static struct link_key k;
+  struct link_key *key = NULL;
+  struct link_key *keydb = NULL;
+  int i, r, f, exist, err, size, keynum;
+
+  if ((dev_id < 0) && (dev_id = hci_get_route(dba)) < 0) {
+    return -1;
+  }
+
+  if (hci_devba(dev_id, &sba) < 0) {
+    return -1;
+  }
+
+  ba2str(&sba, sa); ba2str(dba, da);
+
+  f = open(HCID_KEY_FILE, O_RDWR, 0);        
+  if (f < 0) {
+    syslog(LOG_ERR, "Link key database open failed. %s(%d)",
+	   strerror(errno), errno);
+    return -1;
+  }
+
+  flock(f, LOCK_EX);
+  err = 0;
+  exist = 0;
+
+  size = lseek(f, 0, SEEK_END);
+  if ((size > 0) && (size%sizeof(k) == 0)) {
+    keydb = (struct link_key *)malloc(size);
+    if (keydb == NULL) {
+      err = -1;
+      goto done;
+    }
+    keynum = size/sizeof(k);
+  } else {
+    syslog(LOG_INFO, "%s link key %s %s", exist ? "Remove" : "Not found", 
+	   sa, da);
+    err = -1;
+    goto done;
+  }
+
+  key = keydb; 
+  lseek(f, 0, SEEK_SET);
+  while ((r = read_n(f, &k, sizeof(k)))) {
+    if (!bacmp(&k.sba, &sba) && !bacmp(&k.dba, dba)) {
+      exist = 1;
+    } else {
+      *key = k; key++;
+    }
+  }
+
+  if (exist) {
+    key = keydb;
+    lseek(f, 0, SEEK_SET);
+    ftruncate(f, 0);
+    lseek(f, 0, SEEK_SET);
+    for (i = 0; i < keynum-1; i++) {
+      if ((write_n(f, key, sizeof(*key)) < 0)) {
+	syslog(LOG_ERR, "Link key database write failed. %s(%d)",
+	       strerror(errno), errno);
+	err = -1;
+	goto done;
+      }
+      key++;
+    }
+  }
+  
+  ba2str(&sba, sa); ba2str(dba, da);
+  syslog(LOG_INFO, "%s link key %s %s", exist ? "Remove" : "Not found", 
+	 sa, da);
+
+done:
+  free(keydb);
+  flock(f, LOCK_UN);
+  close(f);
+  return err;
+}
+
+int show_link_keys()
+{
+  char sa[40], da[40];
+  static struct link_key k;
+  int r, f;
+
+  f = open(HCID_KEY_FILE, O_RDONLY, 0);        
+  if (f < 0) {
+    syslog(LOG_ERR, "Link key database open failed. %s(%d)",
+	   strerror(errno), errno);
+    return -1;
+  }
+
+  flock(f, LOCK_EX);
+
+  while ((r = read_n(f, &k, sizeof(k)))) {
+    ba2str(&k.sba, sa); ba2str(&k.dba, da);
+    printf("\t%s - %s\n", sa, da);
+  }
+
+  flock(f, LOCK_UN);
+  close(f);
+  return 0;
+}

[-- Attachment #3: bluez-utils-2.0-rmkey.patch --]
[-- Type: application/octet-stream, Size: 3098 bytes --]

diff -uNr bluez-utils-2.0.orig/hcid/security.c bluez-utils-2.0/hcid/security.c
--- bluez-utils-2.0.orig/hcid/security.c	Fri Jul 19 03:12:46 2002
+++ bluez-utils-2.0/hcid/security.c	Thu Aug  8 17:09:58 2002
@@ -51,6 +51,8 @@
 #include "hcid.h"
 #include "lib.h"
 
+#include <sys/file.h>
+
 static GIOChannel *io_chan[HCI_MAX_DEV];
 
 static int pairing;
@@ -95,8 +97,11 @@
 	int f;
 
 	f = open(hcid.key_file, O_RDONLY);
-	if (f >= 0)
+	if (f >= 0) {
+		flock(f, LOCK_EX);
 		key = __get_link_key(f, sba, dba);
+		flock(f, LOCK_UN);
+	}
 	else if (errno != ENOENT)
 		syslog(LOG_ERR, "Link key database open failed. %s(%d)",
 				strerror(errno), errno);
@@ -135,6 +140,8 @@
 		return;
 	}
 
+	flock(f, LOCK_EX);
+
 	/* Check if key already exist */
 	exist = __get_link_key(f, &key->sba, &key->dba);
 
@@ -149,6 +156,7 @@
 	if (err < 0) {
 		syslog(LOG_ERR, "Link key database seek failed. %s(%d)",
 				strerror(errno), errno);
+		flock(f, LOCK_UN);
 		goto failed;
 	}
 	
@@ -159,6 +167,7 @@
 
 	ba2str(&key->sba, sa); ba2str(&key->dba, da);
 	syslog(LOG_INFO, "%s link key %s %s", exist ? "Replacing" : "Saving", sa, da);
+	flock(f, LOCK_UN);
 
 failed:
 	close(f);
diff -uNr bluez-utils-2.0.orig/tools/hcitool.c bluez-utils-2.0/tools/hcitool.c
--- bluez-utils-2.0.orig/tools/hcitool.c	Tue Jun 25 13:36:09 2002
+++ bluez-utils-2.0/tools/hcitool.c	Fri Aug  9 17:21:38 2002
@@ -865,6 +865,78 @@
 	free(cr);
 }
 
+/* Remove link key */
+
+static struct option rmkey_options[] = {
+	{"help",    0,0, 'h'},
+	{0, 0, 0, 0}
+};
+
+static char *rmkey_help =
+	"Usage:\n"
+	"\trmkey <bdaddr>\n";
+
+static void cmd_rmkey(int dev_id, int argc, char **argv)
+{
+	bdaddr_t bdaddr;
+	int opt, dd;
+
+	for_each_opt(opt, rmkey_options, NULL) {
+		switch(opt) {
+		default:
+			printf(rmkey_help);
+			return;
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc < 1) {
+		printf(rmkey_help);
+		return;
+	}
+
+	baswap(&bdaddr, strtoba(argv[0]));
+
+	if (dev_id < 0) {
+		dev_id = hci_get_route(&bdaddr);
+		if (dev_id < 0) {
+			fprintf(stderr, "Device is not available.\n");
+			exit(1);
+		}
+	}
+
+	if (remove_link_key(dev_id, &bdaddr) == 0)
+	  	printf("ok\n");
+
+}
+
+/* Display link keys */
+
+static struct option keys_options[] = {
+	{"help",    0,0, 'h'},
+	{0, 0, 0, 0}
+};
+
+static char *keys_help = 
+	"Usage:\n"
+	"\tkeys\n";
+
+static void cmd_keys(int dev_id, int argc, char **argv)
+{
+	int opt;
+	for_each_opt(opt, keys_options, NULL) {
+		switch(opt) {
+		default:
+			printf(keys_help);
+			return;
+		}
+	}
+
+	printf("Keys:\n");
+	show_link_keys();
+}
+
 
 struct {
 	char *cmd;
@@ -882,6 +954,10 @@
 	{ "dc",	  cmd_dc,   "Disconnect from remote device"      },
 	{ "cpt",  cmd_cpt,  "Change connection packet type"      },
 	{ "rssi", cmd_rssi, "Display connection RSSI"            },
+
+	{ "rmkey", cmd_rmkey, "Remove link key"                  },
+	{ "keys",  cmd_keys,  "Show link keys"                   },
+
 	{ NULL, NULL, 0}
 };