[PATCH v2] cifs: add ipv6 parsing

[PATCH v2] cifs: add ipv6 parsing

[Elijah Conners]

CIFS currently lacks IPv6 parsing, presenting complications for CIFS
over IPv6.

To parse both IPv4 and IPv6 addresses, the parse_srvaddr() function
was altered; parse_srvaddr() now returns void. To retrieve the IP
address from parse_srvaddr(), the parameters *out6 and *out32, an
in6_addr and a __be32 respectively, are provided. The value of
root_server_addr is determined by if those parameters are set or not.

The parsing in parse_srvaddr() was updated slightly. The character addr
can hold up to 46 characters, the longest a possible IPv6 address can
be. In the while loop, isdigit() has been replaced with isxdigit() to
account for letters present in IPv6 addresses, and *start is also
checked for being a colon. Finally, the function uses inet_pton() to
determine if the address is an IPv6 address; if so, *out6 is equal to
in6, set by inet_pton, otherwise, *out32 is set to in_aton(addr).

Signed-off-by: Elijah Conners <business@elijahpepe.com>
---
 fs/cifs/cifsroot.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/fs/cifs/cifsroot.c b/fs/cifs/cifsroot.c
index 9e91a5a40aae..0246e0792d8e 100644
--- a/fs/cifs/cifsroot.c
+++ b/fs/cifs/cifsroot.c
@@ -14,6 +14,7 @@
 #include <linux/in.h>
 #include <linux/inet.h>
 #include <net/ipconfig.h>
+#include <arpa/inet.h>
 
 #define DEFAULT_MNT_OPTS \
 	"vers=1.0,cifsacl,mfsymlinks,rsize=1048576,wsize=65536,uid=0,gid=0," \
@@ -22,19 +23,24 @@
 static char root_dev[2048] __initdata = "";
 static char root_opts[1024] __initdata = DEFAULT_MNT_OPTS;
 
-static __be32 __init parse_srvaddr(char *start, char *end)
-{
-	/* TODO: ipv6 support */
-	char addr[sizeof("aaa.bbb.ccc.ddd")];
+static void __init parse_srvaddr(char *start, char *end, struct in6_addr *out6, __be32 *out32)
+{	
+	char addr[INET6_ADDRSTRLEN];
+	struct in6_addr in6;
 	int i = 0;
 
 	while (start < end && i < sizeof(addr) - 1) {
-		if (isdigit(*start) || *start == '.')
+		if (isxdigit(*start) || *start == '.' || *start == ':')
 			addr[i++] = *start;
 		start++;
 	}
 	addr[i] = '\0';
-	return in_aton(addr);
+
+	if (inet_pton(AF_INET6, addr, &in6) > 0) {
+		*out6 = in6;
+	} else {
+		*out32 = in_aton(addr);
+	}
 }
 
 /* cifsroot=//<server-ip>/<share>[,options] */
@@ -42,7 +48,8 @@ static int __init cifs_root_setup(char *line)
 {
 	char *s;
 	int len;
-	__be32 srvaddr = htonl(INADDR_NONE);
+	struct in6_addr addr6;
+	__be32 addr32;
 
 	ROOT_DEV = Root_CIFS;
 
@@ -60,7 +67,7 @@ static int __init cifs_root_setup(char *line)
 			return 1;
 		}
 		strlcpy(root_dev, line, len);
-		srvaddr = parse_srvaddr(&line[2], s);
+		parse_srvaddr(&line[2], s, &addr6, &addr32);
 		if (*s) {
 			int n = snprintf(root_opts,
 					 sizeof(root_opts), "%s,%s",
@@ -73,7 +80,11 @@ static int __init cifs_root_setup(char *line)
 		}
 	}
 
-	root_server_addr = srvaddr;
+	if (addr6.is_set) {
+		root_server_addr = addr6;
+	} else if (addr32.is_set) {
+		root_server_addr = addr32;
+	}
 
 	return 1;
 }
-- 
2.29.2.windows.2

Re: [PATCH v2] cifs: add ipv6 parsing

[Steve French]

Can you fix the whitespace error and make sure it merges (cifsroot.c
hasn't changed in over a year so should be easy). I got this error
when trying to apply the patch.

Applying: cifs: add ipv6 parsing
.git/rebase-apply/patch:26: trailing whitespace.
{
error: fs/cifs/cifsroot.c: does not match index
Patch failed at 0001 cifs: add ipv6 parsing

On Mon, Dec 5, 2022 at 11:25 PM Elijah Conners <business@elijahpepe.com> wrote:
>
> CIFS currently lacks IPv6 parsing, presenting complications for CIFS
> over IPv6.
>
> To parse both IPv4 and IPv6 addresses, the parse_srvaddr() function
> was altered; parse_srvaddr() now returns void. To retrieve the IP
> address from parse_srvaddr(), the parameters *out6 and *out32, an
> in6_addr and a __be32 respectively, are provided. The value of
> root_server_addr is determined by if those parameters are set or not.
>
> The parsing in parse_srvaddr() was updated slightly. The character addr
> can hold up to 46 characters, the longest a possible IPv6 address can
> be. In the while loop, isdigit() has been replaced with isxdigit() to
> account for letters present in IPv6 addresses, and *start is also
> checked for being a colon. Finally, the function uses inet_pton() to
> determine if the address is an IPv6 address; if so, *out6 is equal to
> in6, set by inet_pton, otherwise, *out32 is set to in_aton(addr).
>
> Signed-off-by: Elijah Conners <business@elijahpepe.com>
> ---
>  fs/cifs/cifsroot.c | 29 ++++++++++++++++++++---------
>  1 file changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/fs/cifs/cifsroot.c b/fs/cifs/cifsroot.c
> index 9e91a5a40aae..0246e0792d8e 100644
> --- a/fs/cifs/cifsroot.c
> +++ b/fs/cifs/cifsroot.c
> @@ -14,6 +14,7 @@
>  #include <linux/in.h>
>  #include <linux/inet.h>
>  #include <net/ipconfig.h>
> +#include <arpa/inet.h>
>
>  #define DEFAULT_MNT_OPTS \
>         "vers=1.0,cifsacl,mfsymlinks,rsize=1048576,wsize=65536,uid=0,gid=0," \
> @@ -22,19 +23,24 @@
>  static char root_dev[2048] __initdata = "";
>  static char root_opts[1024] __initdata = DEFAULT_MNT_OPTS;
>
> -static __be32 __init parse_srvaddr(char *start, char *end)
> -{
> -       /* TODO: ipv6 support */
> -       char addr[sizeof("aaa.bbb.ccc.ddd")];
> +static void __init parse_srvaddr(char *start, char *end, struct in6_addr *out6, __be32 *out32)
> +{
> +       char addr[INET6_ADDRSTRLEN];
> +       struct in6_addr in6;
>         int i = 0;
>
>         while (start < end && i < sizeof(addr) - 1) {
> -               if (isdigit(*start) || *start == '.')
> +               if (isxdigit(*start) || *start == '.' || *start == ':')
>                         addr[i++] = *start;
>                 start++;
>         }
>         addr[i] = '\0';
> -       return in_aton(addr);
> +
> +       if (inet_pton(AF_INET6, addr, &in6) > 0) {
> +               *out6 = in6;
> +       } else {
> +               *out32 = in_aton(addr);
> +       }
>  }
>
>  /* cifsroot=//<server-ip>/<share>[,options] */
> @@ -42,7 +48,8 @@ static int __init cifs_root_setup(char *line)
>  {
>         char *s;
>         int len;
> -       __be32 srvaddr = htonl(INADDR_NONE);
> +       struct in6_addr addr6;
> +       __be32 addr32;
>
>         ROOT_DEV = Root_CIFS;
>
> @@ -60,7 +67,7 @@ static int __init cifs_root_setup(char *line)
>                         return 1;
>                 }
>                 strlcpy(root_dev, line, len);
> -               srvaddr = parse_srvaddr(&line[2], s);
> +               parse_srvaddr(&line[2], s, &addr6, &addr32);
>                 if (*s) {
>                         int n = snprintf(root_opts,
>                                          sizeof(root_opts), "%s,%s",
> @@ -73,7 +80,11 @@ static int __init cifs_root_setup(char *line)
>                 }
>         }
>
> -       root_server_addr = srvaddr;
> +       if (addr6.is_set) {
> +               root_server_addr = addr6;
> +       } else if (addr32.is_set) {
> +               root_server_addr = addr32;
> +       }
>
>         return 1;
>  }
> --
> 2.29.2.windows.2
>
>


-- 
Thanks,

Steve