ip-address: Support filtering by slave type, too

This patch allows to query all interfaces enslaved to a bridge or bond
using the following syntax:

| ip addr show type bridge_slave

Filtering has to be done in userspace since the kernel does not support
filtering on IFLA_INFO_SLAVE_KIND.

Functionality introduced in this patch is not fully complete since it
does not allow to match on type and slave type at the same time, but it
doesn't prevent implementing a dedicated slave_type match, either.

Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 8766530f7fa7c11b11779b98343039042f8b87fd..56f68eb21c0fc27a1d77e8286b0ea68163c18741 100644 (file)
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -61,6 +61,7 @@ static struct
        int group;
        int master;
        char *kind;
+       char *slave_kind;
 } filter;
 
 static int do_link;
@@ -206,18 +207,27 @@ static void print_linkmode(FILE *f, struct rtattr *tb)
                fprintf(f, "mode %s ", link_modes[mode]);
 }
 
-static char *parse_link_kind(struct rtattr *tb)
+static char *parse_link_kind(struct rtattr *tb, bool slave)
 {
        struct rtattr *linkinfo[IFLA_INFO_MAX+1];
+       int attr = slave ? IFLA_INFO_SLAVE_KIND : IFLA_INFO_KIND;
 
        parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb);
 
-       if (linkinfo[IFLA_INFO_KIND])
-               return RTA_DATA(linkinfo[IFLA_INFO_KIND]);
+       if (linkinfo[attr])
+               return RTA_DATA(linkinfo[attr]);
 
        return "";
 }
 
+static int match_link_kind(struct rtattr **tb, char *kind, bool slave)
+{
+       if (!tb[IFLA_LINKINFO])
+               return -1;
+
+       return strcmp(parse_link_kind(tb[IFLA_LINKINFO], slave), kind);
+}
+
 static void print_linktype(FILE *fp, struct rtattr *tb)
 {
        struct rtattr *linkinfo[IFLA_INFO_MAX+1];
@@ -680,16 +690,11 @@ int print_linkinfo_brief(const struct sockaddr_nl *who,
        } else if (filter.master > 0)
                return -1;
 
-       if (filter.kind) {
-               if (tb[IFLA_LINKINFO]) {
-                       char *kind = parse_link_kind(tb[IFLA_LINKINFO]);
+       if (filter.kind && match_link_kind(tb, filter.kind, 0))
+               return -1;
 
-                       if (strcmp(kind, filter.kind))
-                               return -1;
-               } else {
-                       return -1;
-               }
-       }
+       if (filter.slave_kind && match_link_kind(tb, filter.slave_kind, 1))
+               return -1;
 
        if (n->nlmsg_type == RTM_DELLINK)
                fprintf(fp, "Deleted ");
@@ -781,16 +786,11 @@ int print_linkinfo(const struct sockaddr_nl *who,
        } else if (filter.master > 0)
                return -1;
 
-       if (filter.kind) {
-               if (tb[IFLA_LINKINFO]) {
-                       char *kind = parse_link_kind(tb[IFLA_LINKINFO]);
+       if (filter.kind && match_link_kind(tb, filter.kind, 0))
+               return -1;
 
-                       if (strcmp(kind, filter.kind))
-                               return -1;
-               } else {
-                       return -1;
-               }
-       }
+       if (filter.slave_kind && match_link_kind(tb, filter.slave_kind, 1))
+               return -1;
 
        if (n->nlmsg_type == RTM_DELLINK)
                fprintf(fp, "Deleted ");
@@ -1621,8 +1621,16 @@ static int ipaddr_list_flush_or_save(int argc, char **argv, int action)
                                invarg("Device does not exist\n", *argv);
                        filter.master = ifindex;
                } else if (strcmp(*argv, "type") == 0) {
+                       int soff;
+
                        NEXT_ARG();
-                       filter.kind = *argv;
+                       soff = strlen(*argv) - strlen("_slave");
+                       if (!strcmp(*argv + soff, "_slave")) {
+                               (*argv)[soff] = '\0';
+                               filter.slave_kind = *argv;
+                       } else {
+                               filter.kind = *argv;
+                       }
                } else {
                        if (strcmp(*argv, "dev") == 0) {
                                NEXT_ARG();