netlink-socket: Log Generic Netlink family names.

The ids for Generic Netlink family names aren't very helpful because they
can vary from machine to machine and even from one boot to the next.  So
this change logs their names too.

This only affects logging at DBG level.

Reviewed by Ethan Jackson <ethan@nicira.com>.

diff --git a/lib/netlink-socket.c b/lib/netlink-socket.c
index 27811d8..f4bf864 100644 (file)
--- a/lib/netlink-socket.c
+++ b/lib/netlink-socket.c
@@ -24,6 +24,8 @@
 #include <unistd.h>
 #include "coverage.h"
 #include "dynamic-string.h"
+#include "hash.h"
+#include "hmap.h"
 #include "netlink.h"
 #include "netlink-protocol.h"
 #include "ofpbuf.h"
@@ -91,6 +93,7 @@ nl_sock_create(int protocol, struct nl_sock **sockp)
     }
     sock->protocol = protocol;
     sock->any_groups = false;
+    sock->dump = NULL;
 
     retval = alloc_pid(&sock->pid);
     if (retval) {
@@ -705,10 +708,61 @@ nl_sock_wait(const struct nl_sock *sock, short int events)
 \f
 /* Miscellaneous.  */
 
+struct genl_family {
+    struct hmap_node hmap_node;
+    uint16_t id;
+    char *name;
+};
+
+static struct hmap genl_families = HMAP_INITIALIZER(&genl_families);
+
 static const struct nl_policy family_policy[CTRL_ATTR_MAX + 1] = {
     [CTRL_ATTR_FAMILY_ID] = {.type = NL_A_U16},
 };
 
+static struct genl_family *
+find_genl_family_by_id(uint16_t id)
+{
+    struct genl_family *family;
+
+    HMAP_FOR_EACH_IN_BUCKET (family, hmap_node, hash_int(id, 0),
+                             &genl_families) {
+        if (family->id == id) {
+            return family;
+        }
+    }
+    return NULL;
+}
+
+static void
+define_genl_family(uint16_t id, const char *name)
+{
+    struct genl_family *family = find_genl_family_by_id(id);
+
+    if (family) {
+        if (!strcmp(family->name, name)) {
+            return;
+        }
+        free(family->name);
+    } else {
+        family = xmalloc(sizeof *family);
+        family->id = id;
+        hmap_insert(&genl_families, &family->hmap_node, hash_int(id, 0));
+    }
+    family->name = xstrdup(name);
+}
+
+static const char *
+genl_family_to_name(uint16_t id)
+{
+    if (id == GENL_ID_CTRL) {
+        return "control";
+    } else {
+        struct genl_family *family = find_genl_family_by_id(id);
+        return family ? family->name : "unknown";
+    }
+}
+
 static int do_lookup_genl_family(const char *name)
 {
     struct nl_sock *sock;
@@ -742,9 +796,12 @@ static int do_lookup_genl_family(const char *name)
     retval = nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]);
     if (retval == 0) {
         retval = -EPROTO;
+    } else {
+        define_genl_family(retval, name);
     }
     nl_sock_destroy(sock);
     ofpbuf_delete(reply);
+
     return retval;
 }
 
@@ -811,7 +868,7 @@ free_pid(uint32_t pid)
 }
 \f
 static void
-nlmsghdr_to_string(const struct nlmsghdr *h, struct ds *ds)
+nlmsghdr_to_string(const struct nlmsghdr *h, int protocol, struct ds *ds)
 {
     struct nlmsg_flag {
         unsigned int bits;
@@ -842,6 +899,8 @@ nlmsghdr_to_string(const struct nlmsghdr *h, struct ds *ds)
         ds_put_cstr(ds, "(overrun)");
     } else if (h->nlmsg_type < NLMSG_MIN_TYPE) {
         ds_put_cstr(ds, "(reserved)");
+    } else if (protocol == NETLINK_GENERIC) {
+        ds_put_format(ds, "(%s)", genl_family_to_name(h->nlmsg_type));
     } else {
         ds_put_cstr(ds, "(family-defined)");
     }
@@ -868,7 +927,7 @@ nlmsg_to_string(const struct ofpbuf *buffer, int protocol)
     struct ds ds = DS_EMPTY_INITIALIZER;
     const struct nlmsghdr *h = ofpbuf_at(buffer, 0, NLMSG_HDRLEN);
     if (h) {
-        nlmsghdr_to_string(h, &ds);
+        nlmsghdr_to_string(h, protocol, &ds);
         if (h->nlmsg_type == NLMSG_ERROR) {
             const struct nlmsgerr *e;
             e = ofpbuf_at(buffer, NLMSG_HDRLEN,
@@ -879,7 +938,7 @@ nlmsg_to_string(const struct ofpbuf *buffer, int protocol)
                     ds_put_format(&ds, "(%s)", strerror(-e->error));
                 }
                 ds_put_cstr(&ds, ", in-reply-to(");
-                nlmsghdr_to_string(&e->msg, &ds);
+                nlmsghdr_to_string(&e->msg, protocol, &ds);
                 ds_put_cstr(&ds, "))");
             } else {
                 ds_put_cstr(&ds, " error(truncated)");