From: Chuck Lever Subject: [PATCH 2/4] NFS: Support raw IPv6 address hostnames during NFS mount operation Date: Mon, 23 Jun 2008 12:36:45 -0400 Message-ID: <20080623163644.10539.80258.stgit@ellison.1015granger.net> References: <20080623163129.10539.15565.stgit@ellison.1015granger.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-nfs@vger.kernel.org To: trond.myklebust@netapp.com Return-path: Received: from agminet01.oracle.com ([141.146.126.228]:47384 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754902AbYFWQhN (ORCPT ); Mon, 23 Jun 2008 12:37:13 -0400 In-Reply-To: <20080623163129.10539.15565.stgit-ewv44WTpT0t9HhUboXbp9zCvJB+x5qRC@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- fs/nfs/super.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 82 insertions(+), 8 deletions(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 5e0eefa..98c8110 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1215,14 +1215,9 @@ 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; @@ -1277,6 +1272,85 @@ out_path: } /* + * 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 *