[PATCH 08/12] nfsd: add more information to client info file

["J. Bruce Fields" <bfields@redhat.com>]

From: "J. Bruce Fields" <bfields@redhat.com>

Add ip address, full client-provided identifier, and minor version.
There's much more that could possibly be useful but this is a start.

As with open owners, client identifiers are opaque binary data, but some
clients happen to include useful information in ascii.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/nfsd/nfs4state.c      | 18 ++++++++++++++++++
 fs/seq_file.c            | 17 +++++++++++++++++
 include/linux/seq_file.h |  2 ++
 3 files changed, 37 insertions(+)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c665ce9af773..876c035d2a91 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -42,6 +42,7 @@
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/jhash.h>
+#include <linux/string_helpers.h>
 #include "xdr4.h"
 #include "xdr4cb.h"
 #include "vfs.h"
@@ -2193,6 +2194,19 @@ find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask)
 	return s;
 }
 
+static void seq_escape_quotable_mem(struct seq_file *m, char *data, int len)
+{
+	/* List taken from kstrdup_quotable: */
+	seq_escape_mem(m, data, len, ESCAPE_HEX, "\f\n\r\t\v\a\e\\\"");
+}
+
+static void seq_quote_mem(struct seq_file *m, char *data, int len)
+{
+	seq_printf(m, "\"");
+	seq_escape_quotable_mem(m, data, len);
+	seq_printf(m, "\"");
+}
+
 static int client_info_show(struct seq_file *m, void *v)
 {
 	struct inode *inode = m->private;
@@ -2206,6 +2220,10 @@ static int client_info_show(struct seq_file *m, void *v)
 	clp = container_of(nc, struct nfs4_client, cl_nfsdfs);
 	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
 	seq_printf(m, "clientid: %llx\n", clid);
+	seq_printf(m, "address: %pISpc\n", (struct sockaddr *)&clp->cl_addr);
+	seq_printf(m, "name: ");
+	seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
+	seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
 	drop_client(clp);
 
 	return 0;
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 1dea7a8a5255..bb646e0c5b9c 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -383,6 +383,23 @@ void seq_escape(struct seq_file *m, const char *s, const char *esc)
 }
 EXPORT_SYMBOL(seq_escape);
 
+/**
+ * seq_escape_mem - copy data to buffer, escaping some characters
+ *
+ * See string_escape_mem for explanations of the arguments.
+ */
+void seq_escape_mem(struct seq_file *m, const char *src, size_t isz,
+		    unsigned int flags, const char *only)
+{
+	char *buf;
+	size_t size = seq_get_buf(m, &buf);
+	int ret;
+
+	ret = string_escape_mem(src, isz, buf, size, flags, only);
+	seq_commit(m, ret < size ? ret : -1);
+}
+EXPORT_SYMBOL(seq_escape_mem);
+
 void seq_vprintf(struct seq_file *m, const char *f, va_list args)
 {
 	int len;
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index a121982af0f5..de6ace9e5e6b 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -127,6 +127,8 @@ void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
 		    unsigned long long v, unsigned int width);
 
 void seq_escape(struct seq_file *m, const char *s, const char *esc);
+void seq_escape_mem(struct seq_file *m, const char *src, size_t isz,
+		    unsigned int flags, const char *only);
 
 void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
 		  int rowsize, int groupsize, const void *buf, size_t len,
-- 
2.21.0