Hello,
I've created a patch against dibbler git which should allow
proper resolvconf operation. A private resolv.conf.IFACE file
is kept in /var/lib/dibbler, modified again and again, and
then fed in whole to resolvconf -a IFACE.inet6.
Before patch:
| root@silencer:~# cat /etc/resolvconf/run/interface/lan
| search nebel.canvon.de
After patch:
| root@silencer:~# cat /etc/resolvconf/run/interface/lan
| cat: /etc/resolvconf/run/interface/lan: No such file or directory
| root@silencer:~# cat /etc/resolvconf/run/interface/lan.inet6
|
| nameserver fd94:97cc:7e28:1::15
| search nebel.canvon.de canvon.de
Missing is resolvconf -d. This would have to happen at a point where
definitely no resolver information for that interface is valid anymore;
e.g., when the interface goes down, or at dibbler-client exit.
Also it does not yet clear the private resolv.conf file(s) at start.
But I now have an IPv6 nameserver in my /etc/resolv.conf again.
Regards,
Fabian Pietsch
* Fabian Pietsch (Thu, 04 Dec 2014 02:52:29 +0100):
> Message-ID: <[email protected]>
> From: Fabian Pietsch <[email protected]>
> Subject: Re: Bug#771696: dibbler-client: fails to register DNS server and
> search list properly with resolvconf
> To: [email protected]
> User-Agent: Mutt/1.5.20 (2009-06-14)
>
> Hello,
>
> > The solution would be to gather the resolver data in dns_add() and
> > domain_add(), and then call resolvconf -a iface once, with all
> > information.
>
> I just had a look at dibbler git (which seems to be at the moment almost
> dibbler 1.0.0), and the gathering stuff is already there: The
> /etc/resolv.conf editing code. Dibbler would just need to keep a
> separate resolv.conf (initially empty), perhaps in
> /var/lib/dibbler/resolv.conf, and then after each change feed that
> to "resolvconf -a $IFACE.inet6".
>
> Regards,
> Fabian
--
Fabian "zzz" Pietsch - http://www.canvon.de/
diff --git a/Misc/Portable.h.in b/Misc/Portable.h.in
index d8bc4a9..a2fe9e6 100644
--- a/Misc/Portable.h.in
+++ b/Misc/Portable.h.in
@@ -151,6 +151,7 @@ struct link_state_notify_t
#define SRVCONF_FILE "/etc/dibbler/server.conf"
#define RELCONF_FILE "/etc/dibbler/relay.conf"
#define RESOLVCONF_FILE "/etc/resolv.conf"
+#define PRIV_RESOLVCONF_FILE "/var/lib/dibbler/resolv.conf"
#define NTPCONF_FILE "/etc/ntp.conf"
#define RADVD_FILE "/etc/dibbler/radvd.conf"
#define CLNTPID_FILE "/var/lib/dibbler/client.pid"
diff --git a/Port-linux/lowlevel-options-linux.c b/Port-linux/lowlevel-options-linux.c
index 4000290..d6045a4 100644
--- a/Port-linux/lowlevel-options-linux.c
+++ b/Port-linux/lowlevel-options-linux.c
@@ -9,6 +9,7 @@
#define _BSD_SOURCE
#define _POSIX_SOURCE
+#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
@@ -42,19 +43,24 @@ extern char * Message;
* the pipe needs to be closed by the caller
*
* @param arg1 first command line argument passed to resolvconf
- * @param arg2 second command line argument passed to resolvconf
+ * @param ifname interface name for which to run resolvconf
*
* @return file handler (pipe to resolvconf process) or NULL
*/
-FILE *resolvconf_open(const char *arg1, const char *arg2)
+FILE *resolvconf_open(const char *arg1, const char *ifname)
{
pid_t child;
int pipefd[2];
+ char * ifname_;
if (access(RESOLVCONF, X_OK) != 0)
return NULL;
- if (pipe(pipefd) != 0)
+ if (!asprintf(&ifname_, "%s.inet6", ifname))
return NULL;
+ if (pipe(pipefd) != 0) {
+ free(ifname_);
+ return NULL;
+ }
switch(child = fork()) {
case 0: /* child */
close(pipefd[1]);
@@ -63,19 +69,35 @@ FILE *resolvconf_open(const char *arg1, const char *arg2)
close(pipefd[0]);
/* double fork so init reaps the child */
if (!fork()) { /* child */
- execl(RESOLVCONF, RESOLVCONF, arg1, arg2, (char *)NULL);
+ execl(RESOLVCONF, RESOLVCONF, arg1, ifname_, (char *)NULL);
} /* All other cases are meaningless here */
exit(EXIT_FAILURE);
break;
case EXIT_FAILURE: /* error */
+ free(ifname_);
return NULL;
break;
}
/* parent */
+ free(ifname_);
close(pipefd[0]);
waitpid(child, NULL, 0);
return fdopen(pipefd[1], "w");
}
+
+int resolvconf_feed(FILE * pipe, const char * file) {
+ FILE * f2 = NULL;
+ unsigned int c;
+
+ if (!(f2=fopen(file, "r")))
+ return LOWLEVEL_ERROR_FILE;
+
+ while ((c = fgetc(f2)) != EOF) {
+ fputc(c, pipe);
+ }
+ fclose(f2);
+ return LOWLEVEL_NO_ERROR;
+}
#endif
/* in iproute.c, borrowed from iproute2 */
@@ -232,16 +254,50 @@ int cfg_file_del(const char *file, const char *keyword, const char *value) {
*/
int dns_add(const char * ifname, int ifaceid, const char * addrPlain) {
FILE * f = NULL;
- unsigned char c;
+ char * file;
+ int ret;
#ifdef MOD_RESOLVCONF
/* try to use resolvconf */
f=resolvconf_open("-a", ifname);
+ if (f) {
+ if (!asprintf(&file, PRIV_RESOLVCONF_FILE ".%s", ifname)) {
+ fclose(f);
+ return LOWLEVEL_ERROR_UNSPEC;
+ }
+
+ /* edit private resolv.conf-like file */
+ if (!(ret = dns_add_file(ifname, ifaceid, addrPlain, file))) {
+ free(file);
+ fclose(f);
+ return ret;
+ }
+
+ /* feed that file to resolvconf */
+ ret = resolvconf_feed(f, file);
+ free(file);
+ fclose(f);
+ return ret;
+ }
+
#endif
/* if resolvconf is not available, fallback to normal file append */
- if (!f && !(f=fopen(RESOLVCONF_FILE, "a+")) ) {
- return LOWLEVEL_ERROR_FILE;
+ return dns_add_file(ifname, ifaceid, addrPlain, RESOLVCONF_FILE);
+}
+
+
+/*
+ * results 0 - ok
+ -1 - unable to open temp. file
+ -2 - unable to open resolv.conf file
+ */
+int dns_add_file(const char * ifname, int ifaceid, const char * addrPlain, const char * file) {
+ FILE * f = NULL;
+ unsigned char c;
+
+ if (!(f=fopen(file, "a+")) ) {
+ return LOWLEVEL_ERROR_FILE;
}
fseek(f, -1, SEEK_END);
@@ -260,11 +316,28 @@ int dns_add(const char * ifname, int ifaceid, const char * addrPlain) {
int dns_del(const char * ifname, int ifaceid, const char *addrPlain) {
#ifdef MOD_RESOLVCONF
- FILE *f = NULL;
- /* try to use resolvconf to remove config */
- if ((f=resolvconf_open("-d", ifname))) {
+ FILE * f = NULL;
+ char * file;
+ int ret;
+ /* try to use resolvconf to update config */
+ if ((f=resolvconf_open("-a", ifname))) {
+ if (!asprintf(&file, PRIV_RESOLVCONF_FILE ".%s", ifname)) {
+ fclose(f);
+ return LOWLEVEL_ERROR_UNSPEC;
+ }
+
+ /* edit private resolv.conf-like file */
+ if ((ret = cfg_file_del(file, "nameserver", addrPlain))) {
+ free(file);
+ fclose(f);
+ return ret;
+ }
+
+ /* feed that file to resolvconf */
+ ret = resolvconf_feed(f, file);
+ free(file);
fclose(f);
- return LOWLEVEL_NO_ERROR;
+ return ret;
}
#endif
@@ -272,31 +345,56 @@ int dns_del(const char * ifname, int ifaceid, const char *addrPlain) {
}
int domain_add(const char* ifname, int ifaceid, const char* domain) {
- FILE * f, *f2;
- char buf[512];
- int found = 0;
- unsigned char c;
- struct stat st;
+ FILE * f;
+ char * file;
+ int ret;
#ifdef MOD_RESOLVCONF
/* try to use resolvconf it is available */
if ( (f=resolvconf_open("-a", ifname))) {
- fprintf(f, "search %s\n", domain);
+ if (!asprintf(&file, PRIV_RESOLVCONF_FILE ".%s", ifname)) {
+ fclose(f);
+ return LOWLEVEL_ERROR_UNSPEC;
+ }
+
+ /* edit private resolv.conf-like file */
+ if (ret = domain_add_file(ifname, ifaceid, domain, file)) {
+ free(file);
+ fclose(f);
+ return ret;
+ }
+
+ /* feed that file to resolvconf */
+ ret = resolvconf_feed(f, file);
+ free(file);
fclose(f);
- return LOWLEVEL_NO_ERROR;
+ return ret;
}
#endif
-
+
/* otherwise do the edit on your own */
+ return domain_add_file(ifname, ifaceid, domain, RESOLVCONF_FILE);
+}
+
+int domain_add_file(const char* ifname, int ifaceid, const char* domain, const char* file) {
+ FILE * f, *f2;
+ char buf[512];
+ char * file_old;
+ int found = 0;
+ unsigned char c;
+ struct stat st;
+
memset(&st,0,sizeof(st));
- stat(RESOLVCONF_FILE, &st);
+ stat(file, &st);
- unlink(RESOLVCONF_FILE ".old");
- rename(RESOLVCONF_FILE, RESOLVCONF_FILE ".old");
- if ( !(f = fopen(RESOLVCONF_FILE ".old", "r")) )
+ if (!asprintf(&file_old, "%s.old", file))
+ return LOWLEVEL_ERROR_UNSPEC;
+ unlink(file_old);
+ rename(file, file_old);
+ if ( !(f = fopen(file_old, "r")) )
return LOWLEVEL_ERROR_FILE;
- if ( !(f2 = fopen(RESOLVCONF_FILE, "w+")) ) {
+ if ( !(f2 = fopen(file, "w+")) ) {
fclose(f);
return LOWLEVEL_ERROR_FILE;
}
@@ -332,10 +430,27 @@ int domain_del(const char * ifname, int ifaceid, const char *domain) {
#ifdef MOD_RESOLVCONF
FILE * f;
+ char * file;
+ int ret;
/* try to use resolvconf if it is available */
- if ((f = resolvconf_open("-d", ifname))) {
+ if ((f = resolvconf_open("-a", ifname))) {
+ if (!asprintf(&file, PRIV_RESOLVCONF_FILE ".%s", ifname)) {
+ fclose(f);
+ return LOWLEVEL_ERROR_UNSPEC;
+ }
+
+ /* edit private resolv.conf-like file */
+ if (ret = cfg_file_del(file, "search", domain)) {
+ free(file);
+ fclose(f);
+ return ret;
+ }
+
+ /* feed that file to resolvconf */
+ ret = resolvconf_feed(f, file);
+ free(file);
fclose(f);
- return LOWLEVEL_NO_ERROR;
+ return ret;
}
#endif
