tc: improve the qdisc show command

Before can be possible show only all qeueue disciplines on an interface.
There wasn't a way to get the qdisc info by handle or parent, only full
dump of the disciplines with a following grep/sed usage.

Now new and old options work as expected to filter a qdisc by handle or
parent.

Full syntax of the qdisc show command:

tc qdisc { show | list } [ dev STRING ] [ QDISC_ID ] [ invisible ]
  QDISC_ID := { root | ingress | handle QHANDLE | parent CLASSID }

This change doesn't require any changes in the kernel.

Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/man/man8/tc.8 b/man/man8/tc.8
index 235216b6419483dfca927645f2f8b11552117826..305bc569752b2da20c21460163c57f04ece6ab88 100644 (file)
--- a/man/man8/tc.8
+++ b/man/man8/tc.8
@@ -77,9 +77,13 @@ tc \- show / manipulate traffic control settings
 .B tc
 .RI "[ " OPTIONS " ]"
 .RI "[ " FORMAT " ]"
-.B qdisc show [ dev
+.B qdisc { show | list } [ dev
 \fIDEV\fR
-.B ]
+.B ] [ root | ingress | handle
+\fIQHANDLE\fR
+.B | parent
+\fICLASSID\fR
+.B ] [ invisible ]
 .P
 .B tc
 .RI "[ " OPTIONS " ]"

diff --git a/tc/tc_qdisc.c b/tc/tc_qdisc.c
index 181fe2f0403f5bc5b3f2c009a5912f550c9d0d7c..8eb08c342113d96d8f08b2a1aa1735ff104eb548 100644 (file)
--- a/tc/tc_qdisc.c
+++ b/tc/tc_qdisc.c
@@ -35,11 +35,12 @@ static int usage(void)
                "       [ ingress_block BLOCK_INDEX ] [ egress_block BLOCK_INDEX ]\n"
                "       [ [ QDISC_KIND ] [ help | OPTIONS ] ]\n"
                "\n"
-               "       tc qdisc show [ dev STRING ] [ ingress | clsact ] [ invisible ]\n"
+               "       tc qdisc { show | list } [ dev STRING ] [ QDISC_ID ] [ invisible ]\n"
                "Where:\n"
                "QDISC_KIND := { [p|b]fifo | tbf | prio | cbq | red | etc. }\n"
                "OPTIONS := ... try tc qdisc add <desired QDISC_KIND> help\n"
-               "STAB_OPTIONS := ... try tc qdisc add stab help\n");
+               "STAB_OPTIONS := ... try tc qdisc add stab help\n"
+               "QDISC_ID := { root | ingress | handle QHANDLE | parent CLASSID }\n");
        return -1;
 }
 
@@ -212,6 +213,8 @@ static int tc_qdisc_modify(int cmd, unsigned int flags, int argc, char **argv)
 }
 
 static int filter_ifindex;
+static __u32 filter_parent;
+static __u32 filter_handle;
 
 int print_qdisc(struct nlmsghdr *n, void *arg)
 {
@@ -235,6 +238,12 @@ int print_qdisc(struct nlmsghdr *n, void *arg)
        if (filter_ifindex && filter_ifindex != t->tcm_ifindex)
                return 0;
 
+       if (filter_handle && filter_handle != t->tcm_handle)
+               return 0;
+
+       if (filter_parent && filter_parent != t->tcm_parent)
+               return 0;
+
        parse_rtattr_flags(tb, TCA_MAX, TCA_RTA(t), len, NLA_F_NESTED);
 
        if (tb[TCA_KIND] == NULL) {
@@ -344,21 +353,55 @@ int print_qdisc(struct nlmsghdr *n, void *arg)
 
 static int tc_qdisc_list(int argc, char **argv)
 {
-       struct tcmsg t = { .tcm_family = AF_UNSPEC };
+       struct {
+               struct nlmsghdr n;
+               struct tcmsg t;
+               char buf[256];
+       } req = {
+               .n.nlmsg_type = RTM_GETQDISC,
+               .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
+               .t.tcm_family = AF_UNSPEC,
+       };
+
        char d[IFNAMSIZ] = {};
        bool dump_invisible = false;
+       __u32 handle;
 
        while (argc > 0) {
                if (strcmp(*argv, "dev") == 0) {
                        NEXT_ARG();
                        strncpy(d, *argv, sizeof(d)-1);
+               } else if (strcmp(*argv, "root") == 0) {
+                       if (filter_parent)
+                               invarg("parent is already specified", *argv);
+                       else if (filter_handle)
+                               invarg("handle is already specified", *argv);
+                       filter_parent = TC_H_ROOT;
                } else if (strcmp(*argv, "ingress") == 0 ||
-                          strcmp(*argv, "clsact") == 0) {
-                       if (t.tcm_parent) {
-                               fprintf(stderr, "Duplicate parent ID\n");
-                               usage();
-                       }
-                       t.tcm_parent = TC_H_INGRESS;
+                               strcmp(*argv, "clsact") == 0) {
+                       if (filter_parent)
+                               invarg("parent is already specified", *argv);
+                       else if (filter_handle)
+                               invarg("handle is already specified", *argv);
+                       filter_parent = TC_H_INGRESS;
+               } else if (matches(*argv, "parent") == 0) {
+                       if (filter_parent)
+                               invarg("parent is already specified", *argv);
+                       else if (filter_handle)
+                               invarg("handle is already specified", *argv);
+                       NEXT_ARG();
+                       if (get_tc_classid(&handle, *argv))
+                               invarg("invalid parent ID", *argv);
+                       filter_parent = handle;
+               } else if (matches(*argv, "handle") == 0) {
+                       if (filter_parent)
+                               invarg("parent is already specified", *argv);
+                       else if (filter_handle)
+                               invarg("handle is already specified", *argv);
+                       NEXT_ARG();
+                       if (get_qdisc_handle(&handle, *argv))
+                               invarg("invalid handle ID", *argv);
+                       filter_handle = handle;
                } else if (matches(*argv, "help") == 0) {
                        usage();
                } else if (strcmp(*argv, "invisible") == 0) {
@@ -374,32 +417,18 @@ static int tc_qdisc_list(int argc, char **argv)
        ll_init_map(&rth);
 
        if (d[0]) {
-               t.tcm_ifindex = ll_name_to_index(d);
-               if (!t.tcm_ifindex)
+               req.t.tcm_ifindex = ll_name_to_index(d);
+               if (!req.t.tcm_ifindex)
                        return -nodev(d);
-               filter_ifindex = t.tcm_ifindex;
+               filter_ifindex = req.t.tcm_ifindex;
        }
 
        if (dump_invisible) {
-               struct {
-                       struct nlmsghdr n;
-                       struct tcmsg t;
-                       char buf[256];
-               } req = {
-                       .n.nlmsg_type = RTM_GETQDISC,
-                       .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
-               };
-
-               req.t.tcm_family = AF_UNSPEC;
-
                addattr(&req.n, 256, TCA_DUMP_INVISIBLE);
-               if (rtnl_dump_request_n(&rth, &req.n) < 0) {
-                       perror("Cannot send dump request");
-                       return 1;
-               }
+       }
 
-       } else if (rtnl_dump_request(&rth, RTM_GETQDISC, &t, sizeof(t)) < 0) {
-               perror("Cannot send dump request");
+       if (rtnl_dump_request_n(&rth, &req.n) < 0) {
+               perror("Cannot send request");
                return 1;
        }
 
@@ -427,10 +456,6 @@ int do_qdisc(int argc, char **argv)
                return tc_qdisc_modify(RTM_NEWQDISC, NLM_F_REPLACE, argc-1, argv+1);
        if (matches(*argv, "delete") == 0)
                return tc_qdisc_modify(RTM_DELQDISC, 0,  argc-1, argv+1);
-#if 0
-       if (matches(*argv, "get") == 0)
-               return tc_qdisc_get(RTM_GETQDISC, 0,  argc-1, argv+1);
-#endif
        if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
            || matches(*argv, "lst") == 0)
                return tc_qdisc_list(argc-1, argv+1);