net/utils: generic inet_pton_with_scope helper

Several locations in the stack need to handle ipv4/ipv6
(with scope) and port strings conversion to sockaddr.
Add a helper that takes either AF_INET, AF_INET6 or
AF_UNSPEC (for wildcard) to centralize this handling.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/include/linux/inet.h b/include/linux/inet.h
index 4cca05c9678e760a07c0c8dcd88f73cc90ddfdc1..636ebe87e6f886a2edbb6e3e8bd01b360998127a 100644 (file)
--- a/include/linux/inet.h
+++ b/include/linux/inet.h
@@ -43,6 +43,8 @@
 #define _LINUX_INET_H
 
 #include <linux/types.h>
+#include <net/net_namespace.h>
+#include <linux/socket.h>
 
 /*
  * These mimic similar macros defined in user-space for inet_ntop(3).
@@ -54,4 +56,8 @@
 extern __be32 in_aton(const char *str);
 extern int in4_pton(const char *src, int srclen, u8 *dst, int delim, const char **end);
 extern int in6_pton(const char *src, int srclen, u8 *dst, int delim, const char **end);
+
+extern int inet_pton_with_scope(struct net *net, unsigned short af,
+               const char *src, const char *port, struct sockaddr_storage *addr);
+
 #endif /* _LINUX_INET_H */

diff --git a/net/core/utils.c b/net/core/utils.c
index 6592d7bbed394086a8ba8efcb370fb1d75db4449..f96cf527bb8fcdc67a634ea9cdf9c11213ef4de9 100644 (file)
--- a/net/core/utils.c
+++ b/net/core/utils.c
@@ -26,9 +26,11 @@
 #include <linux/percpu.h>
 #include <linux/init.h>
 #include <linux/ratelimit.h>
+#include <linux/socket.h>
 
 #include <net/sock.h>
 #include <net/net_ratelimit.h>
+#include <net/ipv6.h>
 
 #include <asm/byteorder.h>
 #include <linux/uaccess.h>
@@ -300,6 +302,107 @@ out:
 }
 EXPORT_SYMBOL(in6_pton);
 
+static int inet4_pton(const char *src, u16 port_num,
+               struct sockaddr_storage *addr)
+{
+       struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
+       int srclen = strlen(src);
+
+       if (srclen > INET_ADDRSTRLEN)
+               return -EINVAL;
+
+       if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
+                    '\n', NULL) == 0)
+               return -EINVAL;
+
+       addr4->sin_family = AF_INET;
+       addr4->sin_port = htons(port_num);
+
+       return 0;
+}
+
+static int inet6_pton(struct net *net, const char *src, u16 port_num,
+               struct sockaddr_storage *addr)
+{
+       struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
+       const char *scope_delim;
+       int srclen = strlen(src);
+
+       if (srclen > INET6_ADDRSTRLEN)
+               return -EINVAL;
+
+       if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
+                    '%', &scope_delim) == 0)
+               return -EINVAL;
+
+       if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
+           src + srclen != scope_delim && *scope_delim == '%') {
+               struct net_device *dev;
+               char scope_id[16];
+               size_t scope_len = min_t(size_t, sizeof(scope_id),
+                                        src + srclen - scope_delim - 1);
+
+               memcpy(scope_id, scope_delim + 1, scope_len);
+               scope_id[scope_len] = '\0';
+
+               dev = dev_get_by_name(net, scope_id);
+               if (dev) {
+                       addr6->sin6_scope_id = dev->ifindex;
+                       dev_put(dev);
+               } else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
+                       return -EINVAL;
+               }
+       }
+
+       addr6->sin6_family = AF_INET6;
+       addr6->sin6_port = htons(port_num);
+
+       return 0;
+}
+
+/**
+ * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
+ * @net: net namespace (used for scope handling)
+ * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
+ * @src: the start of the address string
+ * @port: the start of the port string (or NULL for none)
+ * @addr: output socket address
+ *
+ * Return zero on success, return errno when any error occurs.
+ */
+int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
+               const char *src, const char *port, struct sockaddr_storage *addr)
+{
+       u16 port_num;
+       int ret = -EINVAL;
+
+       if (port) {
+               if (kstrtou16(port, 0, &port_num))
+                       return -EINVAL;
+       } else {
+               port_num = 0;
+       }
+
+       switch (af) {
+       case AF_INET:
+               ret = inet4_pton(src, port_num, addr);
+               break;
+       case AF_INET6:
+               ret = inet6_pton(net, src, port_num, addr);
+               break;
+       case AF_UNSPEC:
+               ret = inet4_pton(src, port_num, addr);
+               if (ret)
+                       ret = inet6_pton(net, src, port_num, addr);
+               break;
+       default:
+               pr_err("unexpected address family %d\n", af);
+       };
+
+       return ret;
+}
+EXPORT_SYMBOL(inet_pton_with_scope);
+
 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
                              __be32 from, __be32 to, bool pseudohdr)
 {