[NET]: show bound packet types

Show what protocols are bound to what packet types in /proc/net/ptype
Uses kallsyms to decode function pointers if possible.
Example:
	Type Device      Function
	ALL  eth1     packet_rcv_spkt+0x0
	0800          ip_rcv+0x0
	0806          arp_rcv+0x0
	86dd          :ipv6:ipv6_rcv+0x0

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 8ddc2ab..3af0bdc 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2216,6 +2216,135 @@ static const struct file_operations softnet_seq_fops = {
        .release = seq_release,
 };
 
+static void *ptype_get_idx(loff_t pos)
+{
+       struct packet_type *pt = NULL;
+       loff_t i = 0;
+       int t;
+
+       list_for_each_entry_rcu(pt, &ptype_all, list) {
+               if (i == pos)
+                       return pt;
+               ++i;
+       }
+
+       for (t = 0; t < 16; t++) {
+               list_for_each_entry_rcu(pt, &ptype_base[t], list) {
+                       if (i == pos)
+                               return pt;
+                       ++i;
+               }
+       }
+       return NULL;
+}
+
+static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       rcu_read_lock();
+       return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+       struct packet_type *pt;
+       struct list_head *nxt;
+       int hash;
+
+       ++*pos;
+       if (v == SEQ_START_TOKEN)
+               return ptype_get_idx(0);
+
+       pt = v;
+       nxt = pt->list.next;
+       if (pt->type == htons(ETH_P_ALL)) {
+               if (nxt != &ptype_all)
+                       goto found;
+               hash = 0;
+               nxt = ptype_base[0].next;
+       } else
+               hash = ntohs(pt->type) & 15;
+
+       while (nxt == &ptype_base[hash]) {
+               if (++hash >= 16)
+                       return NULL;
+               nxt = ptype_base[hash].next;
+       }
+found:
+       return list_entry(nxt, struct packet_type, list);
+}
+
+static void ptype_seq_stop(struct seq_file *seq, void *v)
+{
+       rcu_read_unlock();
+}
+
+static void ptype_seq_decode(struct seq_file *seq, void *sym)
+{
+#ifdef CONFIG_KALLSYMS
+       unsigned long offset = 0, symsize;
+       const char *symname;
+       char *modname;
+       char namebuf[128];
+
+       symname = kallsyms_lookup((unsigned long)sym, &symsize, &offset,
+                                 &modname, namebuf);
+
+       if (symname) {
+               char *delim = ":";
+
+               if (!modname)
+                       modname = delim = "";
+               seq_printf(seq, "%s%s%s%s+0x%lx", delim, modname, delim,
+                          symname, offset);
+               return;
+       }
+#endif
+
+       seq_printf(seq, "[%p]", sym);
+}
+
+static int ptype_seq_show(struct seq_file *seq, void *v)
+{
+       struct packet_type *pt = v;
+
+       if (v == SEQ_START_TOKEN)
+               seq_puts(seq, "Type Device      Function\n");
+       else {
+               if (pt->type == htons(ETH_P_ALL))
+                       seq_puts(seq, "ALL ");
+               else
+                       seq_printf(seq, "%04x", ntohs(pt->type));
+
+               seq_printf(seq, " %-8s ",
+                          pt->dev ? pt->dev->name : "");
+               ptype_seq_decode(seq,  pt->func);
+               seq_putc(seq, '\n');
+       }
+
+       return 0;
+}
+
+static const struct seq_operations ptype_seq_ops = {
+       .start = ptype_seq_start,
+       .next  = ptype_seq_next,
+       .stop  = ptype_seq_stop,
+       .show  = ptype_seq_show,
+};
+
+static int ptype_seq_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &ptype_seq_ops);
+}
+
+static const struct file_operations ptype_seq_fops = {
+       .owner   = THIS_MODULE,
+       .open    = ptype_seq_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = seq_release,
+};
+
+
 #ifdef CONFIG_WIRELESS_EXT
 extern int wireless_proc_init(void);
 #else
@@ -2230,6 +2359,9 @@ static int __init dev_proc_init(void)
                goto out;
        if (!proc_net_fops_create("softnet_stat", S_IRUGO, &softnet_seq_fops))
                goto out_dev;
+       if (!proc_net_fops_create("ptype", S_IRUGO, &ptype_seq_fops))
+               goto out_dev2;
+
        if (wireless_proc_init())
                goto out_softnet;
        rc = 0;
@@ -2237,6 +2369,8 @@ out:
        return rc;
 out_softnet:
        proc_net_remove("softnet_stat");
+out_dev2:
+       proc_net_remove("ptype");
 out_dev:
        proc_net_remove("dev");
        goto out;