non-busybox dhcp clients (was: PATCH: ifupdown.c, udhcpc, and standalone shell)

[Eric Spakman]

Hi Gabriel,

>> But the patch is _technically incorrect_, that's the point.
>> [...]
>> What if I have pump in /usr/local/bin? It will not work.
>>
>>
>> I _hate_ systems with scripts riddled with "/usr/bin/something" instead
>>  of just "something". $PATH is there for a reason, guys.
>
> OK, how about this (still against svn 16294) ? It searches for each
> client in $PATH, and executes it if it is found...
>
Looks perfect to me, haven't tested it though.


> Thanks,
> Gabriel
>
Eric

>
>
> diff -NarU5 busybox-svn-16294.orig/networking/ifupdown.c
> busybox-svn-16294/networking/ifupdown.c ---
> busybox-svn-16294.orig/networking/ifupdown.c	2006-10-03
> 13:01:04.000000000 -0400
> +++ busybox-svn-16294/networking/ifupdown.c	2006-10-03 18:25:59.000000000
> -0400
> @@ -448,47 +448,85 @@
> result += execute("ifconfig %iface% down", ifd, exec); #endif
> return ((result == 2) ? 2 : 0); }
>
>
> -static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
> +#ifndef CONFIG_APP_UDHCPC
> +struct dhcp_client_t
> {
> -	if (execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% "
> -			"[[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]", ifd, exec))
> -		return 1;
> +	char *name;
> +	char *startcmd;
> +	char *stopcmd;
> +};
> +
> +static const struct dhcp_client_t ext_dhcp_clients[] = {
> +	{ "udhcpc",
> +		"udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H
> %hostname%]] [[-c %clientid%]] [[-s %script%]]",
> +		"kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
> +	},
> +	{ "pump",
> +		"pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
> +		"pump -i %iface% -k",
> +	},
> +	{ "dhclient",
> +		"dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
> +		"kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
> +	},
> +	{ "dhcpcd",
> +		"dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l
> %leasetime%]] %iface%",
> +		"dhcpcd -k %iface%",
> +	},
> +};
>
>
> -	/* 2006-09-30: The following are deprecated, and should eventually be
> -	 * removed. For non-busybox (i.e., other than udhcpc) clients, use
> -	 * 'iface foo inet manual' in /etc/network/interfaces, and supply
> -	 * start/stop commands explicitly via up/down. */
> -
> -	if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
> -			ifd, exec)) return 1;
> -	if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
> -			ifd, exec)) return 1;
> -	if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]]
> "
> -			"[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
> +static int execable(char *program)
> +{
> +    struct stat buf;
> +	char *path = xstrdup(getenv("PATH"));
> +	char *p;
> +	int found = 0;
> +	for (p = strtok(path, ":"); p && !found; p = strtok(NULL, ":")) {
> +		p = xasprintf("%s/%s", p, program);
> +		found = (stat(p, &buf) == 0) &&
> +				S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode);
> +		free(p);
> +	}
> +	free(path);
> +    return found;
> +}
> +#endif
>
>
> +static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
> +{
> +#ifdef CONFIG_APP_UDHCPC
> +	return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
> +			"-i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
> +			ifd, exec);
> +#else
> +	int i, nclients = sizeof(ext_dhcp_clients) / sizeof(struct
> dhcp_client_t); +	for (i = 0; i < nclients; i++) {
> +		if (execable(ext_dhcp_clients[i].name))
> +			return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
> +	}
> +	bb_error_msg("No dhcp clients found.");
> return 0; +#endif
> }
>
>
> static int dhcp_down(struct interface_defn_t *ifd, execfn *exec) {
> -	if (execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
> -			ifd, exec)) return 1;
> -
> -	/* 2006-09-30: The following are deprecated, and should eventually be
> -	 * removed. For non-busybox (i.e., other than udhcpc) clients, use
> -	 * 'iface foo inet manual' in /etc/network/interfaces, and supply
> -	 * start/stop commands explicitly via up/down. */
> -
> -	if (execute("pump -i %iface% -k", ifd, exec)) return 1;
> -	if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
> -			ifd, exec)) return 1;
> -	if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
> -
> +#ifdef CONFIG_APP_UDHCPC
> +	return execute("kill -TERM "
> +			"`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
> +#else
> +	int i, nclients = sizeof(ext_dhcp_clients) / sizeof(struct
> dhcp_client_t); +	for (i = 0; i < nclients; i++) {
> +		if (execable(ext_dhcp_clients[i].name))
> +			return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
> +	}
> +	bb_error_msg("No dhcp clients found. Using static interface shutdown.");
>  return static_down(ifd, exec); +#endif
> }
>
>
> static int manual_up_down(struct interface_defn_t *ifd, execfn *exec) {
> return 1;
>