Re: [PATCH 1/1] net: dhcp: allow to set transmitted vendor id

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Mar 08, 2012 at 03:03:26PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> From: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
> 
> For net boot setups it is useful to submit boot params like server or
> bootfile over dhcp. To distinguish barebox from e.g. pxe machines,
> a custom vendor id can be sent in dhcp discover/request messages.

Applied, thanks.

Sascha

> 
> E.g. the ISC dhcp server can be configured with
> 
> | if substring(option vendor-class-identifier,0,8) = "barebox:" {
> |       next-server             192.168.3.24;
> |       server-name             "192.168.3.24";
> |       option tftp-server-name "192.168.3.24";
> |       option root-path = concat("/srv/sysroots/by-mac/",
> |          binary-to-ascii (16, 8, "-", substring (hardware, 1, 6)));
> | }
> 
> to sent boot params which are valid for barebox hosts only.
> 
> Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
> Jean-Christophe PLAGNIOL-VILLARD:
>  - update the use dhcp command option
>  - support to set the vendor via env dhcp_vendor_id
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> ---
>  defaultenv/config |    1 +
>  net/dhcp.c        |   42 +++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 38 insertions(+), 5 deletions(-)
> 
> diff --git a/defaultenv/config b/defaultenv/config
> index 9866273..63fc059 100644
> --- a/defaultenv/config
> +++ b/defaultenv/config
> @@ -9,6 +9,7 @@ machine=FIXME
>  # use 'dhcp' to do dhcp in barebox and in kernel
>  # use 'none' if you want to skip kernel ip autoconfiguration
>  ip=dhcp
> +dhcp_vendor_id=barebox
>  
>  # or set your networking parameters here
>  #eth0.ipaddr=a.b.c.d
> diff --git a/net/dhcp.c b/net/dhcp.c
> index d86f9a9..53eed6c 100644
> --- a/net/dhcp.c
> +++ b/net/dhcp.c
> @@ -17,6 +17,7 @@
>  #include <errno.h>
>  #include <magicvar.h>
>  #include <linux/err.h>
> +#include <getopt.h>
>  
>  #define OPT_SIZE 312	/* Minimum DHCP Options size per RFC2131 - results in 576 byte pkt */
>  
> @@ -127,10 +128,12 @@ static void bootp_copy_net_params(struct bootp *bp)
>  /*
>   * Initialize BOOTP extension fields in the request.
>   */
> -static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID, IPaddr_t RequestedIP)
> +static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID,
> +			  IPaddr_t RequestedIP, char *vendor_id)
>  {
>  	u8 *start = e;
>  	u8 *cnt;
> +	int vendor_id_len = vendor_id ? strlen(vendor_id) : 0;
>  
>  	*e++ = 99;		/* RFC1048 Magic Cookie */
>  	*e++ = 130;
> @@ -168,6 +171,13 @@ static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID, IPaddr_t R
>  		*e++ = tmp & 0xff;
>  	}
>  
> +	if (vendor_id_len > 0) {
> +		*e++ = 60;
> +		*e++ = vendor_id_len;
> +		memcpy(e, vendor_id, vendor_id_len);
> +		 e  += vendor_id_len;
> +	}
> +
>  	*e++ = 55;		/* Parameter Request List */
>  	 cnt = e++;		/* Pointer to count of requested items */
>  	*cnt = 0;
> @@ -223,7 +233,8 @@ static int bootp_request(void)
>  		safe_strncpy (bp->bp_file, bfile, sizeof(bp->bp_file));
>  
>  	/* Request additional information from the BOOTP/DHCP server */
> -	ext_len = dhcp_extended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0);
> +	ext_len = dhcp_extended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0,
> +				dhcp_con->priv);
>  
>  	Bootp_id = (uint32_t)get_time_ns();
>  	net_copy_uint32(&bp->bp_id, &Bootp_id);
> @@ -373,7 +384,8 @@ static void dhcp_send_request_packet(struct bootp *bp_offer)
>  	 * Copy options from OFFER packet if present
>  	 */
>  	net_copy_ip(&OfferedIP, &bp->bp_yiaddr);
> -	extlen = dhcp_extended((u8 *)bp->bp_vend, DHCP_REQUEST, net_dhcp_server_ip, OfferedIP);
> +	extlen = dhcp_extended((u8 *)bp->bp_vend, DHCP_REQUEST, net_dhcp_server_ip,
> +				OfferedIP, dhcp_con->priv);
>  
>  	debug("Transmitting DHCPREQUEST packet\n");
>  	net_udp_send(dhcp_con, sizeof(*bp) + extlen);
> @@ -438,9 +450,18 @@ static void dhcp_handler(void *ctx, char *packet, unsigned int len)
>  
>  static int do_dhcp(int argc, char *argv[])
>  {
> -	int ret;
> +	int ret, opt;
> +	char *vendor_id = (char*)getenv("dhcp_vendor_id");
> +
> +	while((opt = getopt(argc, argv, "v:")) > 0) {
> +		switch(opt) {
> +		case 'v':
> +			vendor_id = optarg;
> +			break;
> +		}
> +	}
>  
> -	dhcp_con = net_udp_new(0xffffffff, PORT_BOOTPS, dhcp_handler, NULL);
> +	dhcp_con = net_udp_new(0xffffffff, PORT_BOOTPS, dhcp_handler, vendor_id);
>  	if (IS_ERR(dhcp_con)) {
>  		ret = PTR_ERR(dhcp_con);
>  		goto out;
> @@ -478,9 +499,19 @@ out:
>  	return ret ? 1 : 0;
>  }
>  
> +BAREBOX_CMD_HELP_START(dhcp)
> +BAREBOX_CMD_HELP_USAGE("dhcp [OPTIONS]\n")
> +BAREBOX_CMD_HELP_SHORT("Invoke dhcp client to obtain ip/boot params.\n")
> +BAREBOX_CMD_HELP_OPT  ("-v <vendor_id>",
> +"DHCP Vendor ID (code 60) 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
> +
>  BAREBOX_CMD_START(dhcp)
>  	.cmd		= do_dhcp,
>  	.usage		= "invoke dhcp client to obtain ip/boot params",
> +	BAREBOX_CMD_HELP(cmd_dhcp_help)
>  BAREBOX_CMD_END
>  
>  BAREBOX_MAGICVAR(bootfile, "bootfile returned from DHCP request");
> @@ -488,3 +519,4 @@ BAREBOX_MAGICVAR(nameserver, "Nameserver returned from DHCP request");
>  BAREBOX_MAGICVAR(hostname, "hostname returned from DHCP request");
>  BAREBOX_MAGICVAR(domainname, "domainname returned from DHCP request");
>  BAREBOX_MAGICVAR(rootpath, "rootpath returned from DHCP request");
> +BAREBOX_MAGICVAR(dhcp_vendor_id, "vendor id to send to the DHCP server");
> -- 
> 1.7.7
> 
> 
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