| Message ID | 20180629174529.19915-1-gert@greenie.muc.de |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [Openvpn-devel] Extend push-remove to also handle 'ifconfig'. | expand |
Hi, thanks for taking care of this! IPv4 settings should all be treated like others and never "assumed to be there all the time" anymore :) On 30/06/18 01:45, Gert Doering wrote: > Push-remove (introduced in commit 970312f1850) did not handle "ifconfig" > yet, as both "ifconfig" and "ifconfig-ipv6" are handled differently from > all other pushed options. Since there was no valid use-case to not-push > "ifconfig" (no support on the client side for running IPv6-only) this > was not an issue so far - but with the recent commits to enable ipv6-only > operation it can be a desirable feature. > > The implementation is similar to "push-remove ifconfig-ipv6" - namely, > flagging via a new context option (c->options.push_ifconfig_ipv4_blocked) > and then not creating the push statement in "send_push_reply()". > > While not truly elegant, it's much less invasive than the alternatives > (storing the list of "push-remove" statements somewhere and then checking > in push_option_ex()) > > Trac: #1072 > > Signed-off-by: Gert Doering <gert@greenie.muc.de> > --- > src/openvpn/options.h | 1 + > src/openvpn/push.c | 10 +++++++++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/src/openvpn/options.h b/src/openvpn/options.h > index f7d0145..3a6c33f 100644 > --- a/src/openvpn/options.h > +++ b/src/openvpn/options.h > @@ -425,6 +425,7 @@ struct options > bool push_ifconfig_constraint_defined; > in_addr_t push_ifconfig_constraint_network; > in_addr_t push_ifconfig_constraint_netmask; > + bool push_ifconfig_ipv4_blocked; /* IPv4 */ > bool push_ifconfig_ipv6_defined; /* IPv6 */ > struct in6_addr push_ifconfig_ipv6_local; /* IPv6 */ > int push_ifconfig_ipv6_netbits; /* IPv6 */ > diff --git a/src/openvpn/push.c b/src/openvpn/push.c > index 6a30e47..86ec7ea 100644 > --- a/src/openvpn/push.c > +++ b/src/openvpn/push.c > @@ -342,7 +342,8 @@ prepare_push_reply(struct context *c, struct gc_arena *gc, > > /* ipv4 */ > if (c->c2.push_ifconfig_defined && c->c2.push_ifconfig_local > - && c->c2.push_ifconfig_remote_netmask) > + && c->c2.push_ifconfig_remote_netmask && wrong style: && should go on the next line (unless you can put also the following condition on the same line). > + !o->push_ifconfig_ipv4_blocked) > { > in_addr_t ifconfig_local = c->c2.push_ifconfig_local; > if (c->c2.push_ifconfig_local_alias) > @@ -602,6 +603,13 @@ push_remove_option(struct options *o, const char *p) > { > msg(D_PUSH_DEBUG, "PUSH_REMOVE searching for: '%s'", p); > > + /* ifconfig is special, as not part of the push list */ > + if (streq( p, "ifconfig" )) I know you have simply copy/pasted the code from below, but since at it, please use the right style and remove useless spaces after of before the parentheses. > + { > + o->push_ifconfig_ipv4_blocked = true; > + return; > + } > + > /* ifconfig-ipv6 is special, as not part of the push list */ > if (streq( p, "ifconfig-ipv6" )) > { > Once the small style glitches above, I can give this patch my ACK. I tested with my small environment and it does what it says without breaking other features. While, I think it is ok to take this patch as it is, as a follow up it would probably make sense to treat ifconfig and ifconfig-ipv6 like the other push-remove directives and allow for partial matching. This would make it identical to pull-filter (I think). Cheers,
diff --git a/src/openvpn/options.h b/src/openvpn/options.h index f7d0145..3a6c33f 100644 --- a/src/openvpn/options.h +++ b/src/openvpn/options.h @@ -425,6 +425,7 @@ struct options bool push_ifconfig_constraint_defined; in_addr_t push_ifconfig_constraint_network; in_addr_t push_ifconfig_constraint_netmask; + bool push_ifconfig_ipv4_blocked; /* IPv4 */ bool push_ifconfig_ipv6_defined; /* IPv6 */ struct in6_addr push_ifconfig_ipv6_local; /* IPv6 */ int push_ifconfig_ipv6_netbits; /* IPv6 */ diff --git a/src/openvpn/push.c b/src/openvpn/push.c index 6a30e47..86ec7ea 100644 --- a/src/openvpn/push.c +++ b/src/openvpn/push.c @@ -342,7 +342,8 @@ prepare_push_reply(struct context *c, struct gc_arena *gc, /* ipv4 */ if (c->c2.push_ifconfig_defined && c->c2.push_ifconfig_local - && c->c2.push_ifconfig_remote_netmask) + && c->c2.push_ifconfig_remote_netmask && + !o->push_ifconfig_ipv4_blocked) { in_addr_t ifconfig_local = c->c2.push_ifconfig_local; if (c->c2.push_ifconfig_local_alias) @@ -602,6 +603,13 @@ push_remove_option(struct options *o, const char *p) { msg(D_PUSH_DEBUG, "PUSH_REMOVE searching for: '%s'", p); + /* ifconfig is special, as not part of the push list */ + if (streq( p, "ifconfig" )) + { + o->push_ifconfig_ipv4_blocked = true; + return; + } + /* ifconfig-ipv6 is special, as not part of the push list */ if (streq( p, "ifconfig-ipv6" )) {
Push-remove (introduced in commit 970312f1850) did not handle "ifconfig" yet, as both "ifconfig" and "ifconfig-ipv6" are handled differently from all other pushed options. Since there was no valid use-case to not-push "ifconfig" (no support on the client side for running IPv6-only) this was not an issue so far - but with the recent commits to enable ipv6-only operation it can be a desirable feature. The implementation is similar to "push-remove ifconfig-ipv6" - namely, flagging via a new context option (c->options.push_ifconfig_ipv4_blocked) and then not creating the push statement in "send_push_reply()". While not truly elegant, it's much less invasive than the alternatives (storing the list of "push-remove" statements somewhere and then checking in push_option_ex()) Trac: #1072 Signed-off-by: Gert Doering <gert@greenie.muc.de> --- src/openvpn/options.h | 1 + src/openvpn/push.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-)