[PATCH 3/3] genl: ctrl: support dumping netlink policy

[Johannes Berg]

Support dumping the netlink policy of a given generic netlink
family, the policy (with any sub-policies if appropriate) is
exported by the kernel in a general fashion.

Signed-off-by: Johannes Berg <johan...@sipsolutions.net>
---
 genl/ctrl.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/genl/ctrl.c b/genl/ctrl.c
index 0fb464b01cfb..68099fe97f1a 100644
--- a/genl/ctrl.c
+++ b/genl/ctrl.c
@@ -28,13 +28,15 @@
 static int usage(void)
 {
        fprintf(stderr,"Usage: ctrl <CMD>\n" \
-                      "CMD   := get <PARMS> | list | monitor\n" \
+                      "CMD   := get <PARMS> | list | monitor | policy 
<PARMS>\n" \
                       "PARMS := name <name> | id <id>\n" \
                       "Examples:\n" \
                       "\tctrl ls\n" \
                       "\tctrl monitor\n" \
                       "\tctrl get name foobar\n" \
-                      "\tctrl get id 0xF\n");
+                      "\tctrl get id 0xF\n"
+                      "\tctrl policy name foobar\n"
+                      "\tctrl policy id 0xF\n");
        return -1;
 }
 
@@ -123,7 +125,8 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
            ghdr->cmd != CTRL_CMD_DELFAMILY &&
            ghdr->cmd != CTRL_CMD_NEWFAMILY &&
            ghdr->cmd != CTRL_CMD_NEWMCAST_GRP &&
-           ghdr->cmd != CTRL_CMD_DELMCAST_GRP) {
+           ghdr->cmd != CTRL_CMD_DELMCAST_GRP &&
+           ghdr->cmd != CTRL_CMD_GETPOLICY) {
                fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
                return 0;
        }
@@ -136,7 +139,7 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
        }
 
        attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
-       parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
+       parse_rtattr_flags(tb, CTRL_ATTR_MAX, attrs, len, NLA_F_NESTED);
 
        if (tb[CTRL_ATTR_FAMILY_NAME]) {
                char *name = RTA_DATA(tb[CTRL_ATTR_FAMILY_NAME]);
@@ -159,6 +162,9 @@ static int print_ctrl(struct rtnl_ctrl_data *ctrl,
                __u32 *ma = RTA_DATA(tb[CTRL_ATTR_MAXATTR]);
                fprintf(fp, " max attribs: %d ",*ma);
        }
+       if (tb[CTRL_ATTR_POLICY])
+               nl_print_policy(tb[CTRL_ATTR_POLICY], fp);
+
        /* end of family definitions .. */
        fprintf(fp,"\n");
        if (tb[CTRL_ATTR_OPS]) {
@@ -235,7 +241,9 @@ static int ctrl_list(int cmd, int argc, char **argv)
                exit(1);
        }
 
-       if (cmd == CTRL_CMD_GETFAMILY) {
+       if (cmd == CTRL_CMD_GETFAMILY || cmd == CTRL_CMD_GETPOLICY) {
+               req.g.cmd = cmd;
+
                if (argc != 2) {
                        fprintf(stderr, "Wrong number of params\n");
                        return -1;
@@ -260,7 +268,9 @@ static int ctrl_list(int cmd, int argc, char **argv)
                        fprintf(stderr, "Wrong params\n");
                        goto ctrl_done;
                }
+       }
 
+       if (cmd == CTRL_CMD_GETFAMILY) {
                if (rtnl_talk(&rth, nlh, &answer) < 0) {
                        fprintf(stderr, "Error talking to the kernel\n");
                        goto ctrl_done;
@@ -273,7 +283,7 @@ static int ctrl_list(int cmd, int argc, char **argv)
 
        }
 
-       if (cmd == CTRL_CMD_UNSPEC) {
+       if (cmd == CTRL_CMD_UNSPEC || cmd == CTRL_CMD_GETPOLICY) {
                nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
                nlh->nlmsg_seq = rth.dump = ++rth.seq;
 
@@ -324,6 +334,8 @@ static int parse_ctrl(struct genl_util *a, int argc, char 
**argv)
            matches(*argv, "show") == 0 ||
            matches(*argv, "lst") == 0)
                return ctrl_list(CTRL_CMD_UNSPEC, argc-1, argv+1);
+       if (matches(*argv, "policy") == 0)
+               return ctrl_list(CTRL_CMD_GETPOLICY, argc-1, argv+1);
        if (matches(*argv, "help") == 0)
                return usage();
 
-- 
2.26.2