From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [RFC PATCH iproute2] link dump filter Date: Mon, 7 Jul 2014 08:49:06 -0700 Message-ID: <20140707084906.264c6cd3@samsung-9> References: <1404428835-21011-1-git-send-email-roopa@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, shm@cumulusnetworks.com, nolan@cumulusnetworks.com, sfeldma@cumulusnetworks.com, jhs@mojatatu.com To: roopa@cumulusnetworks.com Return-path: Received: from mail-wi0-f175.google.com ([209.85.212.175]:56156 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756501AbaGIQyf (ORCPT ); Wed, 9 Jul 2014 12:54:35 -0400 Received: by mail-wi0-f175.google.com with SMTP id ho1so3135518wib.2 for ; Wed, 09 Jul 2014 09:54:33 -0700 (PDT) In-Reply-To: <1404428835-21011-1-git-send-email-roopa@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 3 Jul 2014 16:07:15 -0700 roopa@cumulusnetworks.com wrote: > From: Roopa Prabhu > > This patch avoids a full link wildump request when the user has specified > a single link. Uses RTM_GETLINK without the NLM_F_DUMP flag. > > This helps on a system with large number of interfaces. > > This patch currently only uses the link ifindex in the filter. > Hoping to provide a subsequent kernel patch to do link dump filtering on > other attributes in the kernel. > > In iplink_get, to be safe, this patch currently sets the answer buffer > size to the max size that libnetlink rtnl_talk can copy. The current api > does not seem to provide a way to indicate the answer buf size. Good, should be same size as all the other buffers. > > Signed-off-by: Roopa Prabhu > --- > ip/ip_common.h | 1 + > ip/ipaddress.c | 20 +++++++++++++++++--- > ip/iplink.c | 32 ++++++++++++++++++++++++++++++++ > 3 files changed, 50 insertions(+), 3 deletions(-) > > diff --git a/ip/ip_common.h b/ip/ip_common.h > index ac1e4c1..e56d1ac 100644 > --- a/ip/ip_common.h > +++ b/ip/ip_common.h > @@ -51,6 +51,7 @@ extern int do_ipl2tp(int argc, char **argv); > extern int do_tcp_metrics(int argc, char **argv); > extern int do_ipnetconf(int argc, char **argv); > extern int do_iptoken(int argc, char **argv); > +extern int iplink_get(unsigned int flags, char *name, __u32 filt_mask); > > static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb) > { > diff --git a/ip/ipaddress.c b/ip/ipaddress.c > index 8138e86..d111fab 100644 > --- a/ip/ipaddress.c > +++ b/ip/ipaddress.c > @@ -1241,9 +1241,23 @@ static int ipaddr_list_flush_or_save(int argc, char **argv, int action) > exit(0); > } > > - if (rtnl_wilddump_request(&rth, preferred_family, RTM_GETLINK) < 0) { > - perror("Cannot send dump request"); > - exit(1); > + if (filter_dev && filter.group == -1 && do_link == 1) { > + /* > + * If only filter_dev present and none of the other > + * link filters are present, use RTM_GETLINK to get > + * the link device > + */ move comment before if > + if (iplink_get(0, filter_dev, RTEXT_FILTER_VF) < 0) { > + perror("Cannot send link get request"); > + exit(1); > + } > + exit(0); > + } else { Since code always does exit, the else is redundant. > + if (rtnl_wilddump_request(&rth, preferred_family, > + RTM_GETLINK) < 0) { > + perror("Cannot send dump request"); > + exit(1); > + } > } > > if (rtnl_dump_filter(&rth, store_nlmsg, &linfo) < 0) { > diff --git a/ip/iplink.c b/ip/iplink.c > index 0d020ef..7ac2813 100644 > --- a/ip/iplink.c > +++ b/ip/iplink.c > @@ -703,6 +703,38 @@ static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv) > return 0; > } > > +int iplink_get(unsigned int flags, char *name, __u32 filt_mask) > +{ > + int len; > + struct iplink_req req; > + char answer[16384]; > + > + memset(&req, 0, sizeof(req)); > + > + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); > + req.n.nlmsg_flags = NLM_F_REQUEST|flags; > + req.n.nlmsg_type = RTM_GETLINK; > + req.i.ifi_family = preferred_family; > + > + if (name) { > + len = strlen(name) + 1; > + if (len == 1) > + invarg("\"\" is not a valid device identifier\n", > + "name"); > + if (len > IFNAMSIZ) > + invarg("\"name\" too long\n", name); > + addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, len); > + } > + addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask); > + > + if (rtnl_talk(&rth, &req.n, 0, 0, (struct nlmsghdr *)answer) < 0) > + return -2; > + > + print_linkinfo(NULL, (struct nlmsghdr *)answer, stdout); > + > + return 0; > +} > + > #if IPLINK_IOCTL_COMPAT > static int get_ctl_fd(void) > {