[PATCH iproute2 v2] link dump filter
From: <hidden>
Date: 2014-07-16 14:12:46
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Roopa Prabhu <redacted>
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.
changelog from RFC to v1:
- incorporated comments from stephen (fixed comment and fixed if/else block)
changelog from v1 to v2:
- fix whitespaces error
Signed-off-by: Roopa Prabhu <redacted>
---
ip/ip_common.h | 1 +
ip/ipaddress.c | 13 +++++++++++++
ip/iplink.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+)
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..a8f1b07 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c@@ -1241,6 +1241,19 @@ static int ipaddr_list_flush_or_save(int argc, char **argv, int action) exit(0); } + /* + * If only filter_dev present and none of the other + * link filters are present, use RTM_GETLINK to get + * the link device + */ + if (filter_dev && filter.group == -1 && do_link == 1) { + if (iplink_get(0, filter_dev, RTEXT_FILTER_VF) < 0) { + perror("Cannot send link get request"); + exit(1); + } + exit(0); + } + if (rtnl_wilddump_request(&rth, preferred_family, RTM_GETLINK) < 0) { perror("Cannot send dump request"); exit(1);
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) {
--
1.7.10.4