cifs.upcall: allow users to specify dedicated keytab on command-line

Currently cifs.upcall only looks at the default system keytab
(/etc/krb5.keytab). It's often the case however that a dedicated keytab
is desirable. Allow administrators to set one on the command-line.

Reported-by: steve <steve@steve-ss.com>
Signed-off-by: Jeff Layton <jlayton@samba.org>

diff --git a/cifs.upcall.8.in b/cifs.upcall.8.in
index 3ae0562d14771c4bfd8bef4dc6d84a23e303a902..50f79d18331d2a8b956cf0f5a8ca07fd0c5cb9dd 100644 (file)
--- a/cifs.upcall.8.in
+++ b/cifs.upcall.8.in
@@ -22,7 +22,7 @@
 cifs.upcall \- Userspace upcall helper for Common Internet File System (CIFS)
 .SH "SYNOPSIS"
 .HP \w'\ 'u
-cifs\&.upcall [\-\-trust\-dns|\-t] [\-\-version|\-v] [\-\-legacy\-uid|\-l] [--krb5conf=/path/to/krb5.conf|-k /path/to/...] {keyid}
+cifs\&.upcall [\-\-trust\-dns|\-t] [\-\-version|\-v] [\-\-legacy\-uid|\-l] [--krb5conf=/path/to/krb5.conf|-k /path/to/krb5.conf] [--keytab=/path/to/keytab|-K /path/to/keytab] {keyid}
 .SH "DESCRIPTION"
 .PP
 This tool is part of the cifs-utils suite\&.
@@ -44,6 +44,11 @@ This option allows administrators to set an alternate location for the
 krb5.conf file that cifs.upcall will use.
 .RE
 .PP
+\--keytab=/path/to/keytab|-K /path/to/keytab
+.RS 4
+This option allows administrators to specify a keytab file to be used. When a user has no credential cache already established, cifs.upcall will attempt to use this keytab to acquire them. The default is the system-wide keytab /etc/krb5.keytab.
+.RE
+.PP
 \-\-trust\-dns|\-t
 .RS 4
 With krb5 upcalls, the name used as the host portion of the service principal defaults to the hostname portion of the UNC\&. This option allows the upcall program to reverse resolve the network address of the server in order to get the hostname\&.

diff --git a/cifs.upcall.c b/cifs.upcall.c
index 6c0b9de11cc2a05b2c01ba672324a94ed2a5d5a7..c16bdfd144e863e357538d635c7ee5c9192821f1 100644 (file)
--- a/cifs.upcall.c
+++ b/cifs.upcall.c
@@ -805,13 +805,14 @@ lowercase_string(char *c)
 
 static void usage(void)
 {
-       fprintf(stderr, "Usage: %s [-k /path/to/krb5.conf] [-t] [-v] [-l] key_serial\n", prog);
+       fprintf(stderr, "Usage: %s [ -K /path/to/keytab] [-k /path/to/krb5.conf] [-t] [-v] [-l] key_serial\n", prog);
 }
 
 const struct option long_options[] = {
        {"krb5conf", 1, NULL, 'k'},
        {"legacy-uid", 0, NULL, 'l'},
        {"trust-dns", 0, NULL, 't'},
+       {"keytab", 1, NULL, 'K'},
        {"version", 0, NULL, 'v'},
        {NULL, 0, NULL, 0}
 };
@@ -839,7 +840,7 @@ int main(const int argc, char *const argv[])
 
        openlog(prog, 0, LOG_DAEMON);
 
-       while ((c = getopt_long(argc, argv, "ck:ltv", long_options, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "ck:K:ltv", long_options, NULL)) != -1) {
                switch (c) {
                case 'c':
                        /* legacy option -- skip it */
@@ -853,6 +854,9 @@ int main(const int argc, char *const argv[])
                                goto out;
                        }
                        break;
+               case 'K':
+                       keytab_name = optarg;
+                       break;
                case 'l':
                        legacy_uid++;
                        break;