From e9e835c93f5343b3808af8e4a8c47c13aaf47315 Mon Sep 17 00:00:00 2001
From: Kai Wang <kaiwang27@gmail.com>
Date: Mon, 22 Oct 2012 17:52:21 +0000
Subject: [PATCH] Add command line option "-U" and config file option
 "forced_attach". If "-U" or "forced_attach" is set, the uhidd daemon will
 force attaching the interface even if a kernel driver is actively attached or
 uhidd fails to detach the kernel driver.

---
 uhidd/lex.l    |  1 +
 uhidd/parser.y | 25 +++++++++++++++++++++++++
 uhidd/uhidd.c  | 17 +++++++++++++++--
 uhidd/uhidd.h  |  2 ++
 4 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/uhidd/lex.l b/uhidd/lex.l
index 22e8286..d1a5dc6 100644
--- a/uhidd/lex.l
+++ b/uhidd/lex.l
@@ -56,6 +56,7 @@ cc_attach		{ return (T_CC_ATTACH); }
 cc_keymap		{ return (T_CC_KEYMAP); }
 hidaction		{ return (T_HIDACTION); }
 detach_kernel_driver	{ return (T_DETACHKERNELDRIVER); }
+forced_attach		{ return (T_FORCED_ATTACH); }
 
 0x[0-9a-fA-F]+		{
 				yylval.val = strtoul(yytext, NULL, 16);
diff --git a/uhidd/parser.y b/uhidd/parser.y
index 4762434..efc9fa4 100644
--- a/uhidd/parser.y
+++ b/uhidd/parser.y
@@ -66,6 +66,7 @@ static struct device_config dconfig, *dconfig_p;
 %token T_CC_KEYMAP
 %token T_HIDACTION
 %token T_DETACHKERNELDRIVER
+%token T_FORCED_ATTACH
 %token <val> T_NUM
 %token <val> T_HEX
 %token <str> T_USAGE
@@ -149,6 +150,7 @@ conf_entry
 	| vhid_devname
 	| hidaction
 	| detach_kernel_driver
+	| forced_attach
 	;
 
 mouse_attach
@@ -229,6 +231,15 @@ detach_kernel_driver
 		dconfig.detach_kernel_driver = -1;
 	}
 
+forced_attach
+	: T_FORCED_ATTACH "=" T_YES {
+		dconfig.forced_attach = 1;
+	}
+	| T_FORCED_ATTACH "=" T_NO {
+		dconfig.forced_attach = -1;
+	}
+
+
 hidaction
 	: T_HIDACTION "=" "{" hidaction_entry_list "}"
 	;
@@ -447,3 +458,17 @@ config_detach_kernel_driver(struct hid_interface *hi)
 
 	return (uconfig.gconfig.detach_kernel_driver);
 }
+
+int
+config_forced_attach(struct hid_interface *hi)
+{
+	struct device_config *dc;
+
+	dc = config_find_device(hi->vendor_id, hi->product_id, hi->ndx);
+	if (dc != NULL && dc->forced_attach)
+		return (dc->forced_attach);
+	if (clconfig.forced_attach)
+		return (clconfig.forced_attach);
+
+	return (uconfig.gconfig.forced_attach);
+}
diff --git a/uhidd/uhidd.c b/uhidd/uhidd.c
index 2516a4b..d5d7034 100644
--- a/uhidd/uhidd.c
+++ b/uhidd/uhidd.c
@@ -83,7 +83,7 @@ main(int argc, char **argv)
 
 	eval = 0;
 
-	while ((opt = getopt(argc, argv, "c:dDhH:kmosuVv")) != -1) {
+	while ((opt = getopt(argc, argv, "c:dDhH:kmosuUvV")) != -1) {
 		switch(opt) {
 		case 'c':
 			config_file = optarg;
@@ -116,6 +116,9 @@ main(int argc, char **argv)
 		case 'u':
 			clconfig.detach_kernel_driver = 1;
 			break;
+		case 'U':
+			clconfig.forced_attach = 1;
+			break;
 		case 'v':
 			detach = 0;
 			verbose++;
@@ -524,13 +527,23 @@ hid_handle_kernel_driver(struct hid_parser *hp)
 				PRINT1("Unable to detach kernel driver: "
 				    "libusb20_dev_detach_kernel_driver "
 				    "failed\n");
+				if (config_forced_attach(hi) > 0) {
+					PRINT1("Continue anyway\n");
+					return (0);
+				}
 				return (-1);
 			} else
 				PRINT1("kernel driver detached!\n");
 		} else {
+			if (config_forced_attach(hi) > 0) {
+				PRINT1("Continue anyway\n");
+				return (0);
+			}
 			PRINT1("Abort attach since kernel driver is active\n");
 			PRINT1("Please try running uhidd with option '-u' to "
 			    "detach the kernel drivers\n");
+			PRINT1("or specify option '-U' to force attaching the"
+			    " interface\n")
 			return (-1);
 		}
 	}
@@ -759,7 +772,7 @@ usage(void)
 {
 
 	fprintf(stderr, "usage: uhidd [-c config_file] [-H devname] "
-	    "[-dhkmosuvV] /dev/ugen%%u.%%u\n");
+	    "[-dDhkmosuUvV] /dev/ugen%%u.%%u\n");
 	exit(1);
 }
 
diff --git a/uhidd/uhidd.h b/uhidd/uhidd.h
index 87d2d3d..1fd03d0 100644
--- a/uhidd/uhidd.h
+++ b/uhidd/uhidd.h
@@ -182,6 +182,7 @@ struct device_config {
 	int detach_kernel_driver;
 	int vhid_strip_id;
 	char *vhid_devname;
+	int forced_attach;
 	STAILQ_HEAD(, hidaction_config) haclist;
 	STAILQ_ENTRY(device_config) next;
 };
@@ -319,6 +320,7 @@ int		config_read_file(void);
 int		config_vhid_strip_id(struct hid_interface *);
 char		*config_vhid_devname(struct hid_interface *);
 int		config_detach_kernel_driver(struct hid_interface *);
+int		config_forced_attach(struct hid_interface *);
 void		find_hidaction(struct hid_appcol *);
 void		run_hidaction(struct hid_appcol *, struct hid_report *);
 int		ucuse_init(void);