[lxc-devel] [PATCH] Add get_interfaces to the API and start not to filter out loopback interface
S.Çağlar Onur
caglar at 10ur.org
Fri Sep 13 22:44:34 UTC 2013
Hey Stéphane,
On Fri, Sep 13, 2013 at 6:32 PM, Stéphane Graber <stgraber at ubuntu.com>wrote:
> On Fri, Sep 13, 2013 at 06:21:20PM -0400, S.Çağlar Onur wrote:
> > Signed-off-by: S.Çağlar Onur <caglar at 10ur.org>
>
> The loopback filtering was there so that all the software using get_ips
> to wait for the container to be reachable would work.
> Your change will essentially force everyone to do two calls, one for all
> interfaces and one just for lo, then substract the second set from the
> first, that seems suboptimal.
>
> I guess your plan is that most API users will iterate through
> get_interfaces then call get_ips for the interfaces they want, though
> that's just making things harder for little benefit.
>
>
> So I see two ways not to regress in that regard:
> 1) Make scope filtering work with IPv4, so that get_ips() user can pass
> scope=0 and only get global IPv4 and IPv6 addresses.
> 2) Add a no_loopback argument to get_ips.
>
To be honest I removed filtering just because I thought get_ips and
get_interfaces should return everything in the name of the completeness not
because I saw something wrong with them. For that reason I can add
filtering back to get_ips and start to filter loopback on get_interfaces.
My real question is what do you think having a get_interfaces method in the
API? I added that cause there was no way to get interface names from the
container (and get_ips accepts an interface parameter).
> As it's:
> Nacked-by: Stéphane Graber <stgraber at ubuntu.com>
>
> > ---
> > src/lxc/lxccontainer.c | 119
> +++++++++++++++++++++++++++++++++++++++----------
> > src/lxc/lxccontainer.h | 1 +
> > 2 files changed, 97 insertions(+), 23 deletions(-)
> >
> > diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> > index 79237df..14b6942 100644
> > --- a/src/lxc/lxccontainer.c
> > +++ b/src/lxc/lxccontainer.c
> > @@ -1179,23 +1179,26 @@ static bool lxcapi_clear_config_item(struct
> lxc_container *c, const char *key)
> > return ret == 0;
> > }
> >
> > -char** lxcapi_get_ips(struct lxc_container *c, char* interface, char*
> family, int scope)
> > -{
> > - int count = 0;
> > - struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > - char addressOutputBuffer[INET6_ADDRSTRLEN];
> > - void *tempAddrPtr = NULL;
> > - char **addresses = NULL, **temp;
> > - char *address = NULL;
> > +static void exit_from_ns(struct lxc_container *c, int *old_netns, int
> *new_netns) {
> > + /* Switch back to original netns */
> > + if (*old_netns >= 0 && setns(*old_netns, CLONE_NEWNET))
> > + SYSERROR("failed to setns");
> > + if (*new_netns >= 0)
> > + close(*new_netns);
> > + if (*old_netns >= 0)
> > + close(*old_netns);
> > +}
> > +
> > +static bool enter_to_ns(struct lxc_container *c, int *old_netns, int
> *new_netns) {
> > + int ret = 0;
> > char new_netns_path[MAXPATHLEN];
> > - int old_netns = -1, new_netns = -1, ret = 0;
> >
> > if (!c->is_running(c))
> > goto out;
> >
> > /* Save reference to old netns */
> > - old_netns = open("/proc/self/ns/net", O_RDONLY);
> > - if (old_netns < 0) {
> > + *old_netns = open("/proc/self/ns/net", O_RDONLY);
> > + if (*old_netns < 0) {
> > SYSERROR("failed to open /proc/self/ns/net");
> > goto out;
> > }
> > @@ -1205,16 +1208,93 @@ char** lxcapi_get_ips(struct lxc_container *c,
> char* interface, char* family, in
> > if (ret < 0 || ret >= MAXPATHLEN)
> > goto out;
> >
> > - new_netns = open(new_netns_path, O_RDONLY);
> > - if (new_netns < 0) {
> > + *new_netns = open(new_netns_path, O_RDONLY);
> > + if (*new_netns < 0) {
> > SYSERROR("failed to open %s", new_netns_path);
> > goto out;
> > }
> >
> > - if (setns(new_netns, CLONE_NEWNET)) {
> > + if (setns(*new_netns, CLONE_NEWNET)) {
> > SYSERROR("failed to setns");
> > goto out;
> > }
> > + return true;
> > +out:
> > + exit_from_ns(c, old_netns, new_netns);
> > + return false;
> > +}
> > +
> > +char** lxcapi_get_interfaces(struct lxc_container *c)
> > +{
> > + int count = 0;
> > + struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > + char **interfaces = NULL, **temp;
> > + int old_netns = -1, new_netns = -1;
> > +
> > + if (!enter_to_ns(c, &old_netns, &new_netns))
> > + goto out;
> > +
> > + /* Grab the list of interfaces */
> > + if (getifaddrs(&interfaceArray)) {
> > + SYSERROR("failed to get interfaces list");
> > + goto out;
> > + }
> > +
> > + /* Iterate through the interfaces */
> > + for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr =
> tempIfAddr->ifa_next) {
> > + if (tempIfAddr->ifa_addr == NULL)
> > + continue;
> > +
> > + if(tempIfAddr->ifa_addr->sa_family != AF_PACKET) {
> > + continue;
> > + }
> > +
> > + count += 1;
> > + temp = realloc(interfaces, count * sizeof(*interfaces));
> > + if (!temp) {
> > + count -= 1;
> > + goto out;
> > + }
> > + interfaces = temp;
> > + interfaces[count - 1] = strdup(tempIfAddr->ifa_name);
> > + }
> > +
> > +out:
> > + if(interfaceArray)
> > + freeifaddrs(interfaceArray);
> > +
> > + exit_from_ns(c, &old_netns, &new_netns);
> > +
> > + /* Append NULL to the array */
> > + if (count) {
> > + count++;
> > + temp = realloc(interfaces, count * sizeof(*interfaces));
> > + if (!temp) {
> > + int i;
> > + for (i = 0; i < count-1; i++)
> > + free(interfaces[i]);
> > + free(interfaces);
> > + return NULL;
> > + }
> > + interfaces = temp;
> > + interfaces[count - 1] = NULL;
> > + }
> > +
> > + return interfaces;
> > +}
> > +
> > +char** lxcapi_get_ips(struct lxc_container *c, char* interface, char*
> family, int scope)
> > +{
> > + int count = 0;
> > + struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > + char addressOutputBuffer[INET6_ADDRSTRLEN];
> > + void *tempAddrPtr = NULL;
> > + char **addresses = NULL, **temp;
> > + char *address = NULL;
> > + int old_netns = -1, new_netns = -1;
> > +
> > + if (!enter_to_ns(c, &old_netns, &new_netns))
> > + goto out;
> >
> > /* Grab the list of interfaces */
> > if (getifaddrs(&interfaceArray)) {
> > @@ -1241,8 +1321,6 @@ char** lxcapi_get_ips(struct lxc_container *c,
> char* interface, char* family, in
> >
> > if (interface && strcmp(interface, tempIfAddr->ifa_name))
> > continue;
> > - else if (!interface && strcmp("lo", tempIfAddr->ifa_name)
> == 0)
> > - continue;
> >
> > address = (char
> *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
> > tempAddrPtr,
> > @@ -1265,13 +1343,7 @@ out:
> > if(interfaceArray)
> > freeifaddrs(interfaceArray);
> >
> > - /* Switch back to original netns */
> > - if (old_netns >= 0 && setns(old_netns, CLONE_NEWNET))
> > - SYSERROR("failed to setns");
> > - if (new_netns >= 0)
> > - close(new_netns);
> > - if (old_netns >= 0)
> > - close(old_netns);
> > + exit_from_ns(c, &old_netns, &new_netns);
> >
> > /* Append NULL to the array */
> > if (count) {
> > @@ -2576,6 +2648,7 @@ struct lxc_container *lxc_container_new(const char
> *name, const char *configpath
> > c->get_config_path = lxcapi_get_config_path;
> > c->set_config_path = lxcapi_set_config_path;
> > c->clone = lxcapi_clone;
> > + c->get_interfaces = lxcapi_get_interfaces;
> > c->get_ips = lxcapi_get_ips;
> > c->attach = lxcapi_attach;
> > c->attach_run_wait = lxcapi_attach_run_wait;
> > diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
> > index f9ae43b..f17d975 100644
> > --- a/src/lxc/lxccontainer.h
> > +++ b/src/lxc/lxccontainer.h
> > @@ -90,6 +90,7 @@ struct lxc_container {
> > * the length which was our would be printed. */
> > int (*get_config_item)(struct lxc_container *c, const char *key,
> char *retv, int inlen);
> > int (*get_keys)(struct lxc_container *c, const char *key, char
> *retv, int inlen);
> > + char** (*get_interfaces)(struct lxc_container *c);
> > char** (*get_ips)(struct lxc_container *c, char* interface, char*
> family, int scope);
> > /*
> > * get_cgroup_item returns the number of bytes read, or an error
> (<0).
> > --
> > 1.8.1.2
> >
> >
> >
> ------------------------------------------------------------------------------
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> > _______________________________________________
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> > Lxc-devel at lists.sourceforge.net
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>
> --
> Stéphane Graber
> Ubuntu developer
> http://www.ubuntu.com
>
--
S.Çağlar Onur <caglar at 10ur.org>
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