diff mbox series

[iproute2-next,v2,2/2] ip: allow to use alternative names as handle

Message ID 20191002105645.30756-3-jiri@resnulli.us
State Changes Requested
Delegated to: David Ahern
Headers show
Series ip: add support for alternative names | expand

Commit Message

Jiri Pirko Oct. 2, 2019, 10:56 a.m. UTC 
From: Jiri Pirko <jiri@mellanox.com>

Extend ll_name_to_index() to get the index of a netdevice using
alternative interface name. Allow alternative long names to pass checks
in couple of ip link/addr commands.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
rfc->v1:
- added patch description
---
 ip/iplink.c  |  5 +++--
 lib/ll_map.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 3 deletions(-)

Comments

David Ahern Oct. 7, 2019, 9:52 p.m. UTC | #1 
On 10/2/19 4:56 AM, Jiri Pirko wrote:
> @@ -1106,7 +1106,8 @@ int iplink_get(char *name, __u32 filt_mask)
>  
>  	if (name) {
>  		addattr_l(&req.n, sizeof(req),
> -			  IFLA_IFNAME, name, strlen(name) + 1);
> +			  !check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME,

If this trick works here ...

> +			  name, strlen(name) + 1);
>  	}
>  	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
>  
> diff --git a/lib/ll_map.c b/lib/ll_map.c
> index e0ed54bf77c9..04dfb0f2320b 100644
> --- a/lib/ll_map.c
> +++ b/lib/ll_map.c
> @@ -70,7 +70,7 @@ static struct ll_cache *ll_get_by_name(const char *name)
>  		struct ll_cache *im
>  			= container_of(n, struct ll_cache, name_hash);
>  
> -		if (strncmp(im->name, name, IFNAMSIZ) == 0)
> +		if (strcmp(im->name, name) == 0)
>  			return im;
>  	}
>  
> @@ -240,6 +240,43 @@ int ll_index_to_flags(unsigned idx)
>  	return im ? im->flags : -1;
>  }
>  
> +static int altnametoindex(const char *name)
> +{
> +	struct {
> +		struct nlmsghdr		n;
> +		struct ifinfomsg	ifm;
> +		char			buf[1024];
> +	} req = {
> +		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
> +		.n.nlmsg_flags = NLM_F_REQUEST,
> +		.n.nlmsg_type = RTM_GETLINK,
> +	};
> +	struct rtnl_handle rth = {};
> +	struct nlmsghdr *answer;
> +	struct ifinfomsg *ifm;
> +	int rc = 0;
> +
> +	if (rtnl_open(&rth, 0) < 0)
> +		return 0;
> +
> +	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK,
> +		  RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS);
> +	addattr_l(&req.n, sizeof(req), IFLA_ALT_IFNAME, name, strlen(name) + 1);

then why is altnametoindex even needed? why not just use the same check
in the current ll_link_get?

> +
> +	if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0)
> +		goto out;
> +
> +	ifm = NLMSG_DATA(answer);
> +	rc = ifm->ifi_index;
> +
> +	free(answer);
> +
> +	rtnl_close(&rth);
> +out:
> +	return rc;
> +}
> +
> +
>  unsigned ll_name_to_index(const char *name)
>  {
>  	const struct ll_cache *im;
> @@ -257,6 +294,8 @@ unsigned ll_name_to_index(const char *name)
>  		idx = if_nametoindex(name);
>  	if (idx == 0)
>  		idx = ll_idx_a2n(name);
> +	if (idx == 0)
> +		idx = altnametoindex(name);

And then this ordering does not need to be fixed (altname check should
come before if_nametoindex.

>  	return idx;
>  }
>  
>
Jiri Pirko Oct. 9, 2019, 12:41 p.m. UTC | #2 
Mon, Oct 07, 2019 at 11:52:46PM CEST, dsahern@gmail.com wrote:
>On 10/2/19 4:56 AM, Jiri Pirko wrote:
>> @@ -1106,7 +1106,8 @@ int iplink_get(char *name, __u32 filt_mask)
>>  
>>  	if (name) {
>>  		addattr_l(&req.n, sizeof(req),
>> -			  IFLA_IFNAME, name, strlen(name) + 1);
>> +			  !check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME,
>
>If this trick works here ...
>
>> +			  name, strlen(name) + 1);
>>  	}
>>  	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
>>  
>> diff --git a/lib/ll_map.c b/lib/ll_map.c
>> index e0ed54bf77c9..04dfb0f2320b 100644
>> --- a/lib/ll_map.c
>> +++ b/lib/ll_map.c
>> @@ -70,7 +70,7 @@ static struct ll_cache *ll_get_by_name(const char *name)
>>  		struct ll_cache *im
>>  			= container_of(n, struct ll_cache, name_hash);
>>  
>> -		if (strncmp(im->name, name, IFNAMSIZ) == 0)
>> +		if (strcmp(im->name, name) == 0)
>>  			return im;
>>  	}
>>  
>> @@ -240,6 +240,43 @@ int ll_index_to_flags(unsigned idx)
>>  	return im ? im->flags : -1;
>>  }
>>  
>> +static int altnametoindex(const char *name)
>> +{
>> +	struct {
>> +		struct nlmsghdr		n;
>> +		struct ifinfomsg	ifm;
>> +		char			buf[1024];
>> +	} req = {
>> +		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
>> +		.n.nlmsg_flags = NLM_F_REQUEST,
>> +		.n.nlmsg_type = RTM_GETLINK,
>> +	};
>> +	struct rtnl_handle rth = {};
>> +	struct nlmsghdr *answer;
>> +	struct ifinfomsg *ifm;
>> +	int rc = 0;
>> +
>> +	if (rtnl_open(&rth, 0) < 0)
>> +		return 0;
>> +
>> +	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK,
>> +		  RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS);
>> +	addattr_l(&req.n, sizeof(req), IFLA_ALT_IFNAME, name, strlen(name) + 1);
>
>then why is altnametoindex even needed? why not just use the same check
>in the current ll_link_get?

Good point. Reworked. Thanks!


>
>> +
>> +	if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0)
>> +		goto out;
>> +
>> +	ifm = NLMSG_DATA(answer);
>> +	rc = ifm->ifi_index;
>> +
>> +	free(answer);
>> +
>> +	rtnl_close(&rth);
>> +out:
>> +	return rc;
>> +}
>> +
>> +
>>  unsigned ll_name_to_index(const char *name)
>>  {
>>  	const struct ll_cache *im;
>> @@ -257,6 +294,8 @@ unsigned ll_name_to_index(const char *name)
>>  		idx = if_nametoindex(name);
>>  	if (idx == 0)
>>  		idx = ll_idx_a2n(name);
>> +	if (idx == 0)
>> +		idx = altnametoindex(name);
>
>And then this ordering does not need to be fixed (altname check should
>come before if_nametoindex.
>
>>  	return idx;
>>  }
>>  
>> 
>
diff mbox series

Patch

diff --git a/ip/iplink.c b/ip/iplink.c
index e3f8a28fe94c..1684e259b538 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -931,7 +931,7 @@  int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
 				NEXT_ARG();
 			if (dev != name)
 				duparg2("dev", *argv);
-			if (check_ifname(*argv))
+			if (check_altifname(*argv))
 				invarg("\"dev\" not a valid ifname", *argv);
 			dev = *argv;
 		}
@@ -1106,7 +1106,8 @@  int iplink_get(char *name, __u32 filt_mask)
 
 	if (name) {
 		addattr_l(&req.n, sizeof(req),
-			  IFLA_IFNAME, name, strlen(name) + 1);
+			  !check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME,
+			  name, strlen(name) + 1);
 	}
 	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
 
diff --git a/lib/ll_map.c b/lib/ll_map.c
index e0ed54bf77c9..04dfb0f2320b 100644
--- a/lib/ll_map.c
+++ b/lib/ll_map.c
@@ -70,7 +70,7 @@  static struct ll_cache *ll_get_by_name(const char *name)
 		struct ll_cache *im
 			= container_of(n, struct ll_cache, name_hash);
 
-		if (strncmp(im->name, name, IFNAMSIZ) == 0)
+		if (strcmp(im->name, name) == 0)
 			return im;
 	}
 
@@ -240,6 +240,43 @@  int ll_index_to_flags(unsigned idx)
 	return im ? im->flags : -1;
 }
 
+static int altnametoindex(const char *name)
+{
+	struct {
+		struct nlmsghdr		n;
+		struct ifinfomsg	ifm;
+		char			buf[1024];
+	} req = {
+		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+		.n.nlmsg_flags = NLM_F_REQUEST,
+		.n.nlmsg_type = RTM_GETLINK,
+	};
+	struct rtnl_handle rth = {};
+	struct nlmsghdr *answer;
+	struct ifinfomsg *ifm;
+	int rc = 0;
+
+	if (rtnl_open(&rth, 0) < 0)
+		return 0;
+
+	addattr32(&req.n, sizeof(req), IFLA_EXT_MASK,
+		  RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS);
+	addattr_l(&req.n, sizeof(req), IFLA_ALT_IFNAME, name, strlen(name) + 1);
+
+	if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0)
+		goto out;
+
+	ifm = NLMSG_DATA(answer);
+	rc = ifm->ifi_index;
+
+	free(answer);
+
+	rtnl_close(&rth);
+out:
+	return rc;
+}
+
+
 unsigned ll_name_to_index(const char *name)
 {
 	const struct ll_cache *im;
@@ -257,6 +294,8 @@  unsigned ll_name_to_index(const char *name)
 		idx = if_nametoindex(name);
 	if (idx == 0)
 		idx = ll_idx_a2n(name);
+	if (idx == 0)
+		idx = altnametoindex(name);
 	return idx;
 }