[PATCH v2] net/9p/fd: support ipv6 for trans=tcp

Joshua Murphy
2025-01-17T21:52:33Z

Allows specifying an IPv6 address when mounting a remote 9p file system.

Signed-off-by: Joshua Murphy <joshuamurphy@posteo.net>
---
v1 -> v2:
Simplified support using inet_pton_with_scope, initialized
sockaddr_storage variables to zero, and removed unneeded argument
from p9_bind_privport.

net/9p/trans_fd.c | 36 ++++++++++++++++++++----------------
1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 196060dc6..eaf72067e 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -11,6 +11,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/in.h>
+#include <linux/in6.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
@@ -973,45 +974,48 @@ static inline int valid_ipaddr4(const char *buf)

static int p9_bind_privport(struct socket *sock)
{
- struct sockaddr_in cl;
+ struct sockaddr_storage stor = { 0 };
int port, err = -EINVAL;

- memset(&cl, 0, sizeof(cl));
- cl.sin_family = AF_INET;
- cl.sin_addr.s_addr = htonl(INADDR_ANY);
+ stor.ss_family = sock->ops->family;
+ inet_addr_is_any((struct sockaddr *) &stor);
for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
- cl.sin_port = htons((ushort)port);
- err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
+ if (stor.ss_family == AF_INET)
+ ((struct sockaddr_in *) &stor)->sin_port = htons((ushort)port);
+ else
+ ((struct sockaddr_in6 *) &stor)->sin6_port = htons((ushort)port);
+ err = kernel_bind(sock, (struct sockaddr *) &stor, sizeof(stor));
if (err != -EADDRINUSE)
break;
}
return err;
}

-
static int
p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
{
int err;
+ char port_str[6];
struct socket *csocket;
- struct sockaddr_in sin_server;
+ struct sockaddr_storage stor = { 0 };
struct p9_fd_opts opts;

err = parse_opts(args, &opts);
if (err < 0)
return err;

- if (addr == NULL || valid_ipaddr4(addr) < 0)
- return -EINVAL;
+ sprintf(port_str, "%u", opts.port);
+ err = inet_pton_with_scope(current->nsproxy->net_ns, AF_UNSPEC, addr,
+ port_str, &stor);
+ if (addr == NULL || err < 0) {
+ return err;
+ }

csocket = NULL;

client->trans_opts.tcp.port = opts.port;
client->trans_opts.tcp.privport = opts.privport;
- sin_server.sin_family = AF_INET;
- sin_server.sin_addr.s_addr = in_aton(addr);
- sin_server.sin_port = htons(opts.port);
- err = __sock_create(current->nsproxy->net_ns, PF_INET,
+ err = __sock_create(current->nsproxy->net_ns, stor.ss_family,
SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
if (err) {
pr_err("%s (%d): problem creating socket\n",
@@ -1030,8 +1034,8 @@ p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
}

err = READ_ONCE(csocket->ops)->connect(csocket,
- (struct sockaddr *)&sin_server,
- sizeof(struct sockaddr_in), 0);
+ (struct sockaddr *) &stor,
+ sizeof(stor), 0);
if (err < 0) {
pr_err("%s (%d): problem connecting socket to %s\n",
__func__, task_pid_nr(current), addr);
--
2.48.1