[klibc] ipconfig: support setting the DHCP vendor class identifier.klibc-1.4.21

Support setting the DHCP vendor class identifier.  The default is
"Linux ipconfig" for the standalone version and "Linux kinit" for kinit.

Thanks to Geert Stappers for testing and the README update.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

5 files changed, 51 insertions, 9 deletions

diff --git a/usr/kinit/ipconfig/README b/usr/kinit/ipconfig/README
index 46c03fa665551..5c8227a4ad64b 100644
--- a/usr/kinit/ipconfig/README
+++ b/usr/kinit/ipconfig/README
@@ -3,11 +3,14 @@ BOOTP/DHCP client for klibc
 
 Usage:
 
-ipconfig [-c proto] [-d interface] [-n] [-p port] [-t timeout] [interface ...]
+ipconfig [-c proto] [-d interface] [-i identifier]
+	 [-n] [-p port] [-t timeout] [interface ...]
 
 -c proto	Use PROTO as the configuration protocol for all
 		interfaces, unless overridden by specific interfaces.
 -d interface	Either the name of an interface, or a long spec.
+-i identifier	DHCP vendor class identifier.  The default is
+		"Linux ipconfig".
 -n		Do nothing - just print the configuration that would
 		be performed.
 -p port		Send bootp/dhcp broadcasts from PORT, to PORT - 1.
diff --git a/usr/kinit/ipconfig/dhcp_proto.c b/usr/kinit/ipconfig/dhcp_proto.c
index 9a3066099d24f..833c27ef130cd 100644
--- a/usr/kinit/ipconfig/dhcp_proto.c
+++ b/usr/kinit/ipconfig/dhcp_proto.c
@@ -49,12 +49,17 @@ static uint8_t dhcp_end[] = {
 	255,
 };
 
+/* Both iovecs below have to have the same structure, since dhcp_send()
+   pokes at the internals */
+#define DHCP_IOV_LEN 6
+
 static struct iovec dhcp_discover_iov[] = {
 	/* [0] = ip + udp header */
 	/* [1] = bootp header */
 	[2] = {dhcp_discover_hdr, sizeof(dhcp_discover_hdr)},
 	[3] = {dhcp_params, sizeof(dhcp_params)},
-	[4] = {dhcp_end, sizeof(dhcp_end)}
+	/* [4] = DHCP vendor class */
+	[5] = {dhcp_end, sizeof(dhcp_end)}
 };
 
 static struct iovec dhcp_request_iov[] = {
@@ -62,7 +67,8 @@ static struct iovec dhcp_request_iov[] = {
 	/* [1] = bootp header */
 	[2] = {dhcp_request_hdr, sizeof(dhcp_request_hdr)},
 	[3] = {dhcp_params, sizeof(dhcp_params)},
-	[4] = {dhcp_end, sizeof(dhcp_end)}
+	/* [4] = DHCP vendor class */
+	[5] = {dhcp_end, sizeof(dhcp_end)}
 };
 
 /*
@@ -146,7 +152,7 @@ static int dhcp_recv(struct netdev *dev)
 	return dhcp_parse(dev, &bootp, dhcp_options, ret);
 }
 
-static int dhcp_send(struct netdev *dev, struct iovec *vec, int len)
+static int dhcp_send(struct netdev *dev, struct iovec *vec)
 {
 	struct bootp_hdr bootp;
 
@@ -164,9 +170,12 @@ static int dhcp_send(struct netdev *dev, struct iovec *vec, int len)
 	vec[1].iov_base	= &bootp;
 	vec[1].iov_len	= sizeof(struct bootp_hdr);
 
+	vec[4].iov_base = vendor_class_identifier;
+	vec[4].iov_len  = vendor_class_identifier_len;
+
 	DEBUG(("xid %08x secs %d ", bootp.xid, ntohs(bootp.secs)));
 
-	return packet_send(dev, vec, len);
+	return packet_send(dev, vec, DHCP_IOV_LEN);
 }
 
 /*
@@ -179,7 +188,7 @@ int dhcp_send_discover(struct netdev *dev)
 
 	DEBUG(("-> dhcp discover "));
 
-	return dhcp_send(dev, dhcp_discover_iov, 5);
+	return dhcp_send(dev, dhcp_discover_iov);
 }
 
 /*
@@ -200,7 +209,7 @@ int dhcp_send_request(struct netdev *dev)
 
 	DEBUG(("-> dhcp request "));
 
-	return dhcp_send(dev, dhcp_request_iov, 5);
+	return dhcp_send(dev, dhcp_request_iov);
 }
 
 /*
diff --git a/usr/kinit/ipconfig/ipconfig.h b/usr/kinit/ipconfig/ipconfig.h
index e98b51783cb39..064d1d684e0de 100644
--- a/usr/kinit/ipconfig/ipconfig.h
+++ b/usr/kinit/ipconfig/ipconfig.h
@@ -14,6 +14,9 @@
 extern uint16_t cfg_local_port;
 extern uint16_t cfg_remote_port;
 
+extern char vendor_class_identifier[];
+extern int vendor_class_identifier_len;
+
 int ipconfig_main(int argc, char *argv[]);
 uint32_t ipconfig_server_address(void *next);
 
diff --git a/usr/kinit/ipconfig/main.c b/usr/kinit/ipconfig/main.c
index 48b01a5da73f2..fb6109fb03a4b 100644
--- a/usr/kinit/ipconfig/main.c
+++ b/usr/kinit/ipconfig/main.c
@@ -34,6 +34,10 @@ static int loop_timeout = -1;
 static int configured;
 static int bringup_first = 0;
 
+/* DHCP vendor class identifier */
+char vendor_class_identifier[260];
+int vendor_class_identifier_len;
+
 struct state {
 	int state;
 	int restart_state;
@@ -679,6 +683,21 @@ static int check_autoconfig(void)
 	return nauto;
 }
 
+static void set_vendor_identifier(const char *id)
+{
+	int len = strlen(id);
+	if (len >= 255) {
+		fprintf(stderr,
+			"%s: invalid vendor class identifier: "
+			"%s\n", progname, id);
+		longjmp(abort_buf, 1);
+	}
+	memcpy(vendor_class_identifier+2, id, len);
+	vendor_class_identifier[0] = 60;
+	vendor_class_identifier[1] = len;
+	vendor_class_identifier_len = len+2;
+}
+
 int main(int argc, char *argv[])
     __attribute__ ((weak, alias("ipconfig_main")));
 
@@ -699,8 +718,11 @@ int ipconfig_main(int argc, char *argv[])
 	if ((err = setjmp(abort_buf)))
 		return err;
 
+	/* Default vendor identifier */
+	set_vendor_identifier("Linux ipconfig");
+
 	do {
-		c = getopt(argc, argv, "c:d:onp:t:");
+		c = getopt(argc, argv, "c:d:i:onp:t:");
 		if (c == EOF)
 			break;
 
@@ -728,6 +750,9 @@ int ipconfig_main(int argc, char *argv[])
 				longjmp(abort_buf, 1);
 			}
 			break;
+		case 'i':
+			set_vendor_identifier(optarg);
+			break;
 		case 'o':
 			bringup_first = 1;
 			break;
diff --git a/usr/kinit/kinit.c b/usr/kinit/kinit.c
index a4be8bc2ac892..7c33718dc2f02 100644
--- a/usr/kinit/kinit.c
+++ b/usr/kinit/kinit.c
@@ -41,12 +41,14 @@ void dump_args(int argc, char *argv[])
 static int do_ipconfig(int argc, char *argv[])
 {
 	int i, a = 0;
-	char **args = alloca((argc + 1) * sizeof(char *));
+	char **args = alloca((argc + 3) * sizeof(char *));
 
 	if (!args)
 		return -1;
 
 	args[a++] = (char *)"IP-Config";
+	args[a++] = (char *)"-i";
+	args[a++] = (char *)"Linux kinit";
 
 	DEBUG(("Running ipconfig\n"));