[PATCH 6/8] net: dhcp: allow to set transmitted user class

[Jean-Christophe PLAGNIOL-VILLARD]

For net boot setups it is useful to submit boot params like server or
bootfile over dhcp. To distinguish diffrent type of OS running on the same hardware,
a custom vendor id can be sent in dhcp discover/request messages.

E.g. the ISC dhcp server can be configured with

 | option client-uuid code 97 = { unsigned integer 8, string };
 | class "at91sam9x5ek" {
 |         match if substring (option vendor-class-identifier,0,20) = "barebox-at91sam9x5ek";
 |
 |         filename "/tftpboot/atmel/at91sam9x5/sam9x5ek/zImage";
 |         if substring (option dhcp-client-identifier,0,7) = "ser2net" {
 |                 filename "/tftpboot/atmel/at91sam9x5/sam9x5ek/zImage-ser2net";
 |         }
 |         if substring (option client-uuid,0,7) = "test" {
 |                 filename "/tftpboot/atmel/at91sam9x5/sam9x5ek/zImage-ser2net";
 |         }
 |         if substring (option user-class,0,4) = "toto" {
 |                 filename "/tftpboot/atmel/at91sam9x5/sam9x5ek/zImage-toto";
 |         }
 |         option tftp-server-name "192.168.200.98";
 |         option option-150 192.168.200.98;
 |         next-server 192.168.200.98;
 |         option root-path "192.168.200.98:/opt/work/buildroot/build/sam9x5/target";
 | }

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 net/dhcp.c |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/net/dhcp.c b/net/dhcp.c
index ae4bdd0..4c3b9a3 100644
--- a/net/dhcp.c
+++ b/net/dhcp.c
@@ -78,6 +78,7 @@ static uint64_t dhcp_start;
 static char *client_id;
 static char *vendor_id;
 static char *client_uuid;
+static char *user_class;
 
 static int bootp_check_packet(unsigned char *pkt, unsigned src, unsigned len)
 {
@@ -193,6 +194,7 @@ static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID,
 
 	 e += dhcp_set_string_options(e, 60, vendor_id);
 	 e += dhcp_set_string_options(e, 61, client_id);
+	 e += dhcp_set_string_options(e, 77, user_class);
 	 e += dhcp_set_string_options(e, 97, client_uuid);
 
 	*e++ = 55;		/* Parameter Request List */
@@ -494,6 +496,7 @@ static int do_dhcp(int argc, char *argv[])
 	vendor_id = (char*)getenv("dhcp_vendor_id");
 	client_id = (char*)getenv("dhcp_client_id");
 	client_uuid = (char*)getenv("dhcp_client_uuid");
+	user_class = (char*)getenv("dhcp_user_class");
 
 	setenv("bootfile","");
 	setenv("nameserver","");
@@ -504,7 +507,7 @@ static int do_dhcp(int argc, char *argv[])
 	setenv("tftp_server_ip","");
 	setenv("etherboot_file","");
 
-	while((opt = getopt(argc, argv, "v:c:u:")) > 0) {
+	while((opt = getopt(argc, argv, "v:c:u:U:")) > 0) {
 		switch(opt) {
 		case 'v':
 			vendor_id = optarg;
@@ -515,12 +518,16 @@ static int do_dhcp(int argc, char *argv[])
 		case 'u':
 			client_uuid = optarg;
 			break;
+		case 'U':
+			user_class = optarg;
+			break;
 		}
 	}
 
 	pr_debug("vendor_id: '%s'\n", vendor_id);
 	pr_debug("client_id: '%s'\n", client_id);
 	pr_debug("client_uuid: '%s'\n", client_uuid);
+	pr_debug("user_class: '%s'\n", user_class);
 
 	dhcp_con = net_udp_new(0xffffffff, PORT_BOOTPS, dhcp_handler, NULL);
 	if (IS_ERR(dhcp_con)) {
@@ -574,6 +581,10 @@ BAREBOX_CMD_HELP_OPT  ("-c <client_id>",
 BAREBOX_CMD_HELP_OPT  ("-u <client_uuid>",
 "DHCP Client UUID (code 97) submitted in DHCP requests. It can\n"
 "be used in the DHCP server's configuration to select options\n"
+"(e.g. bootfile or server) which are valid for barebox clients only.\n")
+BAREBOX_CMD_HELP_OPT  ("-U <user_class>",
+"DHCP User class (code 77) submitted in DHCP requests. It can\n"
+"be used in the DHCP server's configuration to select options\n"
 "(e.g. bootfile or server) which are valid for barebox clients only.\n");
 BAREBOX_CMD_HELP_END
 
@@ -591,6 +602,7 @@ BAREBOX_MAGICVAR(rootpath, "rootpath returned from DHCP request");
 BAREBOX_MAGICVAR(dhcp_vendor_id, "vendor id to send to the DHCP server");
 BAREBOX_MAGICVAR(dhcp_client_uuid, "cliend uuid to send to the DHCP server");
 BAREBOX_MAGICVAR(dhcp_client_id, "cliend id to send to the DHCP server");
+BAREBOX_MAGICVAR(dhcp_user_class, "user class to send to the DHCP server");
 BAREBOX_MAGICVAR(tftp_server_name, "TFTP server Name returned from DHCP request");
 BAREBOX_MAGICVAR(tftp_server_ip, "TFTP server IP returned from DHCP request");
 BAREBOX_MAGICVAR(etherboot_file, "Etherboot File returned from DHCP request");
-- 
1.7.9.1