udhcpc startup config

[Shonk]

I want to add a hard coded dhcp option pre built into the firmware

I can ofc killall udhcpc and then run below
udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -O33 -O249 -x 61:hex -x 60:hex

but would like to cleanly insert it into the firmware without having to kill udhcpc

im trying to find how udhcpc is started in the source but i just cant seem to find it

im just not used to everything running from a ramdisk

im also wanting to change upnpd settings but also cant find how the config is generated

if someone can point out where i should be looking in the source that would be great

 

[ColinTaylor]

It's set in ./router/rc/udhcpc.c

 

[ColinTaylor]

im also wanting to change upnpd settings

You can use:

/jffs/configs/upnp.conf or
/jffs/configs/upnp.conf.add or
/jffs/scripts/upnp.postconf

https://github.com/RMerl/asuswrt-merlin/wiki/Custom-config-files

 

[Shonk]

thats a cool feature
but im looking to edit how the config is generated in the source
to avoid using jffs

so that it just works with a fresh factory reset

 

[ColinTaylor]

It's done in ./router/rc/services.c

Look for

void start_upnp(void)

 

[Shonk]

this looks like a winner in udhcpc.c


start_udhcpc(char *wan_ifname, int unit, pid_t *ppid)
{
char tmp[100], prefix[] = "wanXXXXXXXXXX_";
char pid[sizeof("/var/run/udhcpcXXXXXXXXXX.pid")];
char clientid[sizeof("61:") + (32+32+1)*2];
char *value;
char *dhcp_argv[] = { "udhcpc",
"-i", wan_ifname,
"-p", (snprintf(pid, sizeof(pid), "/var/run/udhcpc%d.pid", unit), pid),
"-s", "/tmp/udhcpc",
NULL, /* -t2 */
NULL, /* -T5 */
NULL, /* -A120 */
NULL, /* -b */
NULL, NULL, /* -H wan_hostname */
NULL, /* -Oroutes */
NULL, /* -Ostaticroutes */
NULL, /* -Omsstaticroutes */
#ifdef __CONFIG_IPV6__
NULL, /* -Oip6rd rfc */
NULL, /* -Oip6rd comcast */
#endif
#ifdef RTCONFIG_DSL
NULL, NULL, /* -x 61:wan_clientid */
#endif
NULL, NULL, /* -x 61:wan_clientid (non-DSL) */
NULL };
int index = 7; /* first NULL */
int dr_enable;

i presume im good just just edit that to

"/tmp/udhcpc -x 61:hex -x 60:hex"

 

[ColinTaylor]

That looks promising, but there appears to be something built-in to do that:

nvram set wan_dhcpc_options="61:hex 60:hex"

 

[ColinTaylor]

That looks promising, but there appears to be something built-in to do that:

No, I was wrong. wan_dhcpc_options is linked to the GUI option "Manual clientid (for some ISPs)" and only sets option 61.

 

[Shonk]

the command looked good but didnt pull an ip

gona try it slightly different

/* 0: disable, 1: MS routes, 2: RFC routes, 3: Both */
dr_enable = nvram_get_int("dr_enable_x");
if (dr_enable != 0) {
dhcp_argv[index++] = "-O33"; /* routes */
if (dr_enable & (1 << 0))
dhcp_argv[index++] = "-O249"; /* "msstaticroutes" */
if (dr_enable & (1 << 1))
dhcp_argv[index++] = "-O121"; /* "staticroutes" */
dhcp_argv[index++] = "-x 61:hex"; /* "msstaticroutes" */
if (dr_enable & (1 << 1))
dhcp_argv[index++] = "-x 60:hex"; /* "msstaticroutes" */
if (dr_enable & (1 << 1))
}

 

[ColinTaylor]

Don't know whether you'd need to increase the number of elements in the array? (I'm not a C programmer)

                NULL, NULL,     /* -H wan_hostname */
                NULL,           /* -Oroutes */
                NULL,           /* -Ostaticroutes */
                NULL,           /* -Omsstaticroutes */
[B]                NULL,           /* -x 61:hex */
                NULL,           /* -x 60:hex */[/B]
#ifdef __CONFIG_IPV6__
                NULL,           /* -Oip6rd rfc */
                NULL,           /* -Oip6rd comcast */
#endif

 

[Shonk]

im flying in the dark here just gona keep slinging mud until something sticks

 

[ColinTaylor]

the command looked good but didnt pull an ip

Just found this in a completely unrelated post on the internet:

if [ -n "$dhcp_client_id" ]; then
    # convert client id to hex
    hex_client_id=`hexify $dhcp_client_id`
    # -C surpresses default MAC address as client id;
    # -x 61:hex-encoded-client-id
    dhcp_client_id_arg="-C -x 61:$hex_client_id"
fi

Maybe you need the "-C" option?

 

[Shonk]

by default its

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -O33 -O249

This works

killall udhcpc
udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -O33 -O249 -x 61:hex -x 60:hex

also works but is slow pulling an ip 5 secs or so
killall udhcpc
udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61:hex -x 60:hex -O33 -O249

when using
"-s", "/tmp/udhcpc -x 61:hex -x 60:hex",

it looks to be good but truncates off the screen in ps so cant tell for sure that the command is 100% correct

and doesnt pull an ip

i just tried

killall udhcpc
udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -C -x 61:hex -x 60:hex -O33 -O249

and it pulled instantly

odd thats its fine with -O33 -O249 first without -C but not with -O33 -O249 after

 

[Shonk]

ok i have found out the problem but im unsure how to fix it

"/tmp/udhcpc -x 61:hex -x 60:hex"

results in a ps of

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61:hex -x 60:hex

i can killall udhcpc then copy paste the ps

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61:hex -x 60:hex

it pulls an ip straight away

but if i ps again it shows as

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61 hex -x 60 hex

 

[ColinTaylor]

Can I just confirm something? When you say:

"-x 61:hex"

what you are in fact typing is something like:

"-x 61:006d6f6e23206c6170746f70"

Am I correct?

If I specifiy a client ID of "01234" through the GUI it results in this:

# ps w | grep dhcp
  911 admin     1444 S    udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -t2 -T5 -A160 -O33 -O249 -x 61 3031323334

So it looks like the removal of the : is normal?

 

[Shonk]

all of above correct

"/tmp/udhcpc -x 61:hex -x 60:hex" in udhcpc.c

should result in a ps of

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61 hex -x 60 hex

but it results in a ps of

udhcpc -i eth0 -p /var/run/udhcpc0.pid -s /tmp/udhcpc -x 61:hex -x 60:hex


hence my problem

if i do a killall udhcpc and manually paste the command it works fine

 

[ColinTaylor]

How about these 3 changes:

        char *dhcp_argv[] = { "udhcpc",
                "-i", wan_ifname,
                "-p", (snprintf(pid, sizeof(pid), "/var/run/udhcpc%d.pid", unit), pid),
                "-s", "/tmp/udhcpc",
[B]                "-x", "61:hex",
                "-x", "60:hex",[/B]
                NULL,           /* -t2 */
                NULL,           /* -T5 */
                NULL,           /* -A120 */
                NULL,           /* -b */
                NULL, NULL,     /* -H wan_hostname */
                NULL,           /* -Oroutes */
                NULL,           /* -Ostaticroutes */
                NULL,           /* -Omsstaticroutes */
#ifdef __CONFIG_IPV6__
                NULL,           /* -Oip6rd rfc */
                NULL,           /* -Oip6rd comcast */
#endif
#ifdef RTCONFIG_DSL
                NULL, NULL,     /* -x 61:wan_clientid */
#endif
                NULL, NULL,     /* -x 61:wan_clientid (non-DSL) */
                NULL };
[B]        int index = 11;         /* first NULL */[/B]
        int dr_enable;

It's still ugly because of the potential for multiple 61 options if there's a clientid already set in the GUI/nvram.

 

[Shonk]

trying it now thanks

int index = 11;

that was 7 shouldnt it goto 9 as i have added two lines?

 

[Shonk]

tried it with 9 it resulted in

building it with 11 now

 

[ColinTaylor]

int index = 11;

that was 7 shouldnt it goto 9 as i have added two lines?

No, because you've added 4 elements to the array. They just happen to have been written as 2 lines of code, it could equally have been written as 4 lines of code (with 1 element on each line).

If you set the index to 9 the other parameters will overwrite the "-x" and "60:hex".

P.S. Can I ask why you need to set the clientid like this rather than using the built-in facilty (GUI/nvram)? Is it because you need to set some non-alphanumeric value?