[PATCH] af_netlink - convert to seq_file

[Stephen Hemminger <shemminger@xxxxxxxx>]

Convert af_netlink to use seq_file interface.
Tested on 2.6.0-test4 bk latest.

diff -Nru a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
--- a/net/netlink/af_netlink.c  Tue Sep  2 11:56:11 2003
+++ b/net/netlink/af_netlink.c  Tue Sep  2 11:56:11 2003
@@ -40,6 +40,7 @@
 #include <linux/netdevice.h>
 #include <linux/rtnetlink.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/smp_lock.h>
 #include <linux/notifier.h>
 #include <linux/security.h>
@@ -964,62 +965,108 @@
 
 #endif
 
-
 #ifdef CONFIG_PROC_FS
-static int netlink_read_proc(char *buffer, char **start, off_t offset,
-                            int length, int *eof, void *data)
+static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
 {
-       off_t pos=0;
-       off_t begin=0;
-       int len=0;
        int i;
        struct sock *s;
        struct hlist_node *node;
-       
-       len+= sprintf(buffer,"sk       Eth Pid    Groups   "
-                     "Rmem     Wmem     Dump     Locks\n");
-       
+       loff_t off = 0;
+
        for (i=0; i<MAX_LINKS; i++) {
-               read_lock(&nl_table_lock);
                sk_for_each(s, node, &nl_table[i]) {
-                       struct netlink_opt *nlk = nlk_sk(s);
+                       if (off == pos) {
+                               seq->private = (void *) i;
+                               return s;
+                       }
+                       ++off;
+               }
+       }
+       return NULL;
+}
 
-                       len+=sprintf(buffer+len,"%p %-3d %-6d %08x %-8d %-8d %p 
%d",
-                                    s,
-                                    s->sk_protocol,
-                                    nlk->pid,
-                                    nlk->groups,
-                                    atomic_read(&s->sk_rmem_alloc),
-                                    atomic_read(&s->sk_wmem_alloc),
-                                    nlk->cb,
-                                    atomic_read(&s->sk_refcnt)
-                                    );
+static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       read_lock(&nl_table_lock);
+       return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : (void *) 1;
+}
+
+static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+       struct sock *s;
+
+       ++*pos;
 
-                       buffer[len++]='\n';
+       if (v == (void *) 1) 
+               return netlink_seq_socket_idx(seq, 0);
                
-                       pos=begin+len;
-                       if(pos<offset) {
-                               len=0;
-                               begin=pos;
-                       }
-                       if(pos>offset+length) {
-                               read_unlock(&nl_table_lock);
-                               goto done;
+       s = sk_next(v);
+       if (!s) {
+               int i = (int) seq->private; 
+
+               while (++i < MAX_LINKS) {
+                       s = sk_head(&nl_table[i]);
+                       if (s) {
+                               seq->private = (void *) i;
+                               break;
                        }
                }
-               read_unlock(&nl_table_lock);
        }
-       *eof = 1;
+       return s;
+}
 
-done:
-       *start=buffer+(offset-begin);
-       len-=(offset-begin);
-       if(len>length)
-               len=length;
-       if(len<0)
-               len=0;
-       return len;
+static void netlink_seq_stop(struct seq_file *seq, void *v)
+{
+       read_unlock(&nl_table_lock);
+}
+
+
+static int netlink_seq_show(struct seq_file *seq, void *v)
+{
+       if (v == (void *)1) 
+               seq_puts(seq,
+                        "sk       Eth Pid    Groups   "
+                        "Rmem     Wmem     Dump     Locks\n");
+       else {
+               struct sock *s = v;
+               struct netlink_opt *nlk = nlk_sk(s);
+
+               seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
+                          s,
+                          s->sk_protocol,
+                          nlk->pid,
+                          nlk->groups,
+                          atomic_read(&s->sk_rmem_alloc),
+                          atomic_read(&s->sk_wmem_alloc),
+                          nlk->cb,
+                          atomic_read(&s->sk_refcnt)
+                       );
+
+       }
+       return 0;
 }
+
+struct seq_operations netlink_seq_ops = {
+       .start  = netlink_seq_start,
+       .next   = netlink_seq_next,
+       .stop   = netlink_seq_stop,
+       .show   = netlink_seq_show,
+};
+
+
+static int netlink_seq_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &netlink_seq_ops);
+}
+
+static struct file_operations netlink_seq_fops = {
+       .owner          = THIS_MODULE,
+       .open           = netlink_seq_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
 #endif
 
 int netlink_register_notifier(struct notifier_block *nb)
@@ -1069,7 +1116,7 @@
        }
        sock_register(&netlink_family_ops);
 #ifdef CONFIG_PROC_FS
-       create_proc_read_entry("net/netlink", 0, 0, netlink_read_proc, NULL);
+       proc_net_fops_create("netlink", 0, &netlink_seq_fops);
 #endif
        /* The netlink device handler may be needed early. */ 
        rtnetlink_init();
@@ -1079,7 +1126,7 @@
 static void __exit netlink_proto_exit(void)
 {
        sock_unregister(PF_NETLINK);
-       remove_proc_entry("net/netlink", NULL);
+       proc_net_remove("netlink");
 }
 
 core_initcall(netlink_proto_init);