From d1aa08257312f1439c1ab7c8a18e3856f9530f46 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 23 Jun 2008 12:36:45 -0400 Subject: [PATCH] NFS: Support raw IPv6 address hostnames during NFS mount operation Traditionally the mount command has looked for a ":" to separate the server's hostname from the export path in the mounted on device name, like this: mount server:/export /mounted/on/dir The server's hostname is "server" and the export path is "/export". You can also substitute a specific IPv4 network address for the server hostname, like this: mount 192.168.0.55:/export /mounted/on/dir Raw IPv6 addresses present a problem, however, because they look something like this: fe80::200:5aff:fe00:30b Note the use of colons. To get around the presence of colons, copy the Solaris convention used for mounting IPv6 servers by address: wrap a raw IPv6 address with square brackets. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 90 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 82 insertions(+), 8 deletions(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index c4ee8b3a27c1..ea4abd266a7a 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1195,14 +1195,9 @@ static int nfs_try_mount(struct nfs_parsed_mount_data *args, return status; } -/* - * Split "dev_name" into "hostname:export_path". - * - * Note: caller frees hostname and export path, even on error. - */ -static int nfs_parse_devname(const char *dev_name, - char **hostname, size_t maxnamlen, - char **export_path, size_t maxpathlen) +static int nfs_parse_simple_hostname(const char *dev_name, + char **hostname, size_t maxnamlen, + char **export_path, size_t maxpathlen) { size_t len; char *colon, *comma; @@ -1256,6 +1251,85 @@ out_path: return -ENAMETOOLONG; } +/* + * Hostname has square brackets around it because it contains one or + * more colons. We look for the first closing square bracket, and a + * colon must follow it. + */ +static int nfs_parse_protected_hostname(const char *dev_name, + char **hostname, size_t maxnamlen, + char **export_path, size_t maxpathlen) +{ + size_t len; + char *start, *end; + + start = (char *)(dev_name + 1); + + end = strchr(start, ']'); + if (end == NULL) + goto out_bad_devname; + if (*(end + 1) != ':') + goto out_bad_devname; + + len = end - start; + if (len > maxnamlen) + goto out_hostname; + + /* N.B. caller will free nfs_server.hostname in all cases */ + *hostname = kstrndup(start, len, GFP_KERNEL); + if (*hostname == NULL) + goto out_nomem; + + end += 2; + len = strlen(end); + if (len > maxpathlen) + goto out_path; + *export_path = kstrndup(end, len, GFP_KERNEL); + if (!*export_path) + goto out_nomem; + + return 0; + +out_bad_devname: + dfprintk(MOUNT, "NFS: device name not in host:path format\n"); + return -EINVAL; + +out_nomem: + dfprintk(MOUNT, "NFS: not enough memory to parse device name\n"); + return -ENOMEM; + +out_hostname: + dfprintk(MOUNT, "NFS: server hostname too long\n"); + return -ENAMETOOLONG; + +out_path: + dfprintk(MOUNT, "NFS: export pathname too long\n"); + return -ENAMETOOLONG; +} + +/* + * Split "dev_name" into "hostname:export_path". + * + * The leftmost colon demarks the split between the server's hostname + * and the export path. If the hostname starts with a left square + * bracket, then it may contain colons. + * + * Note: caller frees hostname and export path, even on error. + */ +static int nfs_parse_devname(const char *dev_name, + char **hostname, size_t maxnamlen, + char **export_path, size_t maxpathlen) +{ + if (*dev_name == '[') + return nfs_parse_protected_hostname(dev_name, + hostname, maxnamlen, + export_path, maxpathlen); + + return nfs_parse_simple_hostname(dev_name, + hostname, maxnamlen, + export_path, maxpathlen); +} + /* * Validate the NFS2/NFS3 mount data * - fills in the mount root filehandle -- 2.20.1