From d387a5c50bca619d56f276a69627c2e1c6e5c548 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 10 Dec 2012 06:10:46 -0500 Subject: cifs: parse the device name into UNC and prepath This should fix a regression that was introduced when the new mount option parser went in. Also, when the unc= and prefixpath= options are provided, check their values against the ones we parsed from the device string. If they differ, then throw a warning that tells the user that we're using the values from the unc= option for now, but that that will change in 3.10. Pavel Shilovsky Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 88 insertions(+), 7 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 94c4484c9ea..7635b5db26a 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1096,6 +1096,52 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol) return 0; } +/* + * Parse a devname into substrings and populate the vol->UNC and vol->prepath + * fields with the result. Returns 0 on success and an error otherwise. + */ +static int +cifs_parse_devname(const char *devname, struct smb_vol *vol) +{ + char *pos; + const char *delims = "/\\"; + size_t len; + + /* make sure we have a valid UNC double delimiter prefix */ + len = strspn(devname, delims); + if (len != 2) + return -EINVAL; + + /* find delimiter between host and sharename */ + pos = strpbrk(devname + 2, delims); + if (!pos) + return -EINVAL; + + /* skip past delimiter */ + ++pos; + + /* now go until next delimiter or end of string */ + len = strcspn(pos, delims); + + /* move "pos" up to delimiter or NULL */ + pos += len; + vol->UNC = kstrndup(devname, pos - devname, GFP_KERNEL); + if (!vol->UNC) + return -ENOMEM; + + convert_delimiter(vol->UNC, '\\'); + + /* If pos is NULL, or is a bogus trailing delimiter then no prepath */ + if (!*pos++ || !*pos) + return 0; + + vol->prepath = kstrdup(pos, GFP_KERNEL); + if (!vol->prepath) + return -ENOMEM; + + return 0; +} + static int cifs_parse_mount_options(const char *mountdata, const char *devname, struct smb_vol *vol) @@ -1181,6 +1227,16 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, vol->backupuid_specified = false; /* no backup intent for a user */ vol->backupgid_specified = false; /* no backup intent for a group */ + /* + * For now, we ignore -EINVAL errors under the assumption that the + * unc= and prefixpath= options will be usable. + */ + if (cifs_parse_devname(devname, vol) == -ENOMEM) { + printk(KERN_ERR "CIFS: Unable to allocate memory to parse " + "device string.\n"); + goto out_nomem; + } + while ((data = strsep(&options, separator)) != NULL) { substring_t args[MAX_OPT_ARGS]; unsigned long option; @@ -1566,18 +1622,31 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, got_ip = true; break; case Opt_unc: - kfree(vol->UNC); + string = vol->UNC; vol->UNC = match_strdup(args); - if (vol->UNC == NULL) + if (vol->UNC == NULL) { + kfree(string); goto out_nomem; + } convert_delimiter(vol->UNC, '\\'); if (vol->UNC[0] != '\\' || vol->UNC[1] != '\\') { - printk(KERN_WARNING "CIFS: UNC Path does not " + kfree(string); + printk(KERN_ERR "CIFS: UNC Path does not " "begin with // or \\\\\n"); goto cifs_parse_mount_err; } + /* Compare old unc= option to new one */ + if (!string || strcmp(string, vol->UNC)) + printk(KERN_WARNING "CIFS: the value of the " + "unc= mount option does not match the " + "device string. Using the unc= option " + "for now. In 3.10, that option will " + "be ignored and the contents of the " + "device string will be used " + "instead. (%s != %s)\n", string, + vol->UNC); break; case Opt_domain: string = match_strdup(args); @@ -1616,10 +1685,22 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, if (*args[0].from == '/' || *args[0].from == '\\') args[0].from++; - kfree(vol->prepath); + string = vol->prepath; vol->prepath = match_strdup(args); - if (vol->prepath == NULL) + if (vol->prepath == NULL) { + kfree(string); goto out_nomem; + } + /* Compare old prefixpath= option to new one */ + if (!string || strcmp(string, vol->prepath)) + printk(KERN_WARNING "CIFS: the value of the " + "prefixpath= mount option does not " + "match the device string. Using the " + "prefixpath= option for now. In 3.10, " + "that option will be ignored and the " + "contents of the device string will be " + "used instead.(%s != %s)\n", string, + vol->prepath); break; case Opt_iocharset: string = match_strdup(args); @@ -1777,8 +1858,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, } #endif if (!vol->UNC) { - cERROR(1, "CIFS mount error: No UNC path (e.g. -o " - "unc=\\\\192.168.1.100\\public) specified"); + cERROR(1, "CIFS mount error: No usable UNC path provided in " + "device string or in unc= option!"); goto cifs_parse_mount_err; } -- cgit v1.2.3