Remove __contains__ from mock object for consistency with actual
[samba.git] / client / cifs.upcall.c
index 82b9f7b91ba46fd36798bc91b4475d39177e0b02..42632a0da09308ebc1f54256932b489626253c18 100644 (file)
@@ -26,64 +26,171 @@ create dns_resolver * * /usr/local/sbin/cifs.upcall %k
 */
 
 #include "includes.h"
+#include "../libcli/auth/spnego.h"
+#include "smb_krb5.h"
 #include <keyutils.h>
+#include <getopt.h>
 
 #include "cifs_spnego.h"
 
-const char *CIFSSPNEGO_VERSION = "1.2";
+#define        CIFS_DEFAULT_KRB5_DIR           "/tmp"
+#define        CIFS_DEFAULT_KRB5_PREFIX        "krb5cc_"
+
+#define        MAX_CCNAME_LEN                  PATH_MAX + 5
+
+const char *CIFSSPNEGO_VERSION = "1.3";
 static const char *prog = "cifs.upcall";
-typedef enum _secType {
+typedef enum _sectype {
        NONE = 0,
        KRB5,
        MS_KRB5
-} secType_t;
+} sectype_t;
+
+/* does the ccache have a valid TGT? */
+static time_t
+get_tgt_time(const char *ccname) {
+       krb5_context context;
+       krb5_ccache ccache;
+       krb5_cc_cursor cur;
+       krb5_creds creds;
+       krb5_principal principal;
+       time_t credtime = 0;
+       char *realm = NULL;
+       TALLOC_CTX *mem_ctx;
+
+       if (krb5_init_context(&context)) {
+               syslog(LOG_DEBUG, "%s: unable to init krb5 context", __func__);
+               return 0;
+       }
 
-/*
- * given a process ID, get the value of the KRB5CCNAME environment variable
- * in the context of that process. On error, just return NULL.
- */
-static char *
-get_krb5_ccname(pid_t pid)
+       if (krb5_cc_resolve(context, ccname, &ccache)) {
+               syslog(LOG_DEBUG, "%s: unable to resolve krb5 cache", __func__);
+               goto err_cache;
+       }
+
+       if (krb5_cc_set_flags(context, ccache, 0)) {
+               syslog(LOG_DEBUG, "%s: unable to set flags", __func__);
+               goto err_cache;
+       }
+
+       if (krb5_cc_get_principal(context, ccache, &principal)) {
+               syslog(LOG_DEBUG, "%s: unable to get principal", __func__);
+               goto err_princ;
+       }
+
+       if (krb5_cc_start_seq_get(context, ccache, &cur)) {
+               syslog(LOG_DEBUG, "%s: unable to seq start", __func__);
+               goto err_ccstart;
+       }
+
+       if ((realm = smb_krb5_principal_get_realm(context, principal)) == NULL) {
+               syslog(LOG_DEBUG, "%s: unable to get realm", __func__);
+               goto err_ccstart;
+       }
+
+       mem_ctx = talloc_init("cifs.upcall");
+       while (!credtime && !krb5_cc_next_cred(context, ccache, &cur, &creds)) {
+               char *name;
+               if (smb_krb5_unparse_name(mem_ctx, context, creds.server, &name)) {
+                       syslog(LOG_DEBUG, "%s: unable to unparse name", __func__);
+                       goto err_endseq;
+               }
+               if (krb5_realm_compare(context, creds.server, principal) &&
+                   strnequal(name, KRB5_TGS_NAME, KRB5_TGS_NAME_SIZE) &&
+                   strnequal(name+KRB5_TGS_NAME_SIZE+1, realm, strlen(realm)) &&
+                   creds.times.endtime > time(NULL))
+                       credtime = creds.times.endtime;
+                krb5_free_cred_contents(context, &creds);
+               TALLOC_FREE(name);
+        }
+err_endseq:
+       TALLOC_FREE(mem_ctx);
+        krb5_cc_end_seq_get(context, ccache, &cur);
+err_ccstart:
+       krb5_free_principal(context, principal);
+err_princ:
+#if defined(KRB5_TC_OPENCLOSE)
+       krb5_cc_set_flags(context, ccache, KRB5_TC_OPENCLOSE);
+#endif
+       krb5_cc_close(context, ccache);
+err_cache:
+       krb5_free_context(context);
+       return credtime;
+}
+
+static int
+krb5cc_filter(const struct dirent *dirent)
 {
-       int fd;
-       ssize_t len, left;
+       if (strstr(dirent->d_name, CIFS_DEFAULT_KRB5_PREFIX))
+               return 1;
+       else
+               return 0;
+}
 
-       /*
-        * FIXME: sysconf for ARG_MAX instead? Kernel seems to be limited to a
-        * page however, so it may not matter.
-        */
-       char buf[4096];
-       char *p, *value = NULL;
-       
-       buf[4095] = '\0';
-       snprintf(buf, 4095, "/proc/%d/environ", pid);
-       fd = open(buf, O_RDONLY);
-       if (fd < 0)
+/* search for a credcache that looks like a likely candidate */
+static char *
+find_krb5_cc(const char *dirname, uid_t uid)
+{
+       struct dirent **namelist;
+       struct stat sbuf;
+       char ccname[MAX_CCNAME_LEN], *credpath, *best_cache = NULL;
+       int i, n;
+       time_t cred_time, best_time = 0;
+
+       n = scandir(dirname, &namelist, krb5cc_filter, NULL);
+       if (n < 0) {
+               syslog(LOG_DEBUG, "%s: scandir error on directory '%s': %s",
+                                 __func__, dirname, strerror(errno));
                return NULL;
+       }
 
-       /* FIXME: don't assume that we get it all in the first read? */
-       len = read(fd, buf, 4096);
-       close(fd);
-       if (len < 0)
-               return NULL;
+       for (i = 0; i < n; i++) {
+               snprintf(ccname, sizeof(ccname), "FILE:%s/%s", dirname,
+                        namelist[i]->d_name);
+               credpath = ccname + 5;
+               syslog(LOG_DEBUG, "%s: considering %s", __func__, credpath);
 
-       left = len;
-       p = buf;
+               if (lstat(credpath, &sbuf)) {
+                       syslog(LOG_DEBUG, "%s: stat error on '%s': %s",
+                                         __func__, credpath, strerror(errno));
+                       free(namelist[i]);
+                       continue;
+               }
+               if (sbuf.st_uid != uid) {
+                       syslog(LOG_DEBUG, "%s: %s is owned by %u, not %u",
+                                       __func__, credpath, sbuf.st_uid, uid);
+                       free(namelist[i]);
+                       continue;
+               }
+               if (!S_ISREG(sbuf.st_mode)) {
+                       syslog(LOG_DEBUG, "%s: %s is not a regular file",
+                                       __func__, credpath);
+                       free(namelist[i]);
+                       continue;
+               }
+               if (!(cred_time = get_tgt_time(ccname))) {
+                       syslog(LOG_DEBUG, "%s: %s is not a valid credcache.",
+                                       __func__, ccname);
+                       free(namelist[i]);
+                       continue;
+               }
 
-       /* can't have valid KRB5CCNAME if there are < 13 bytes left */
-       while (left > 12) {
-               if (strncmp("KRB5CCNAME=", p, 11)) {
-                       p += strnlen(p, left);
-                       ++p;
-                       left = buf + len - p;
+               if (cred_time <= best_time) {
+                       syslog(LOG_DEBUG, "%s: %s expires sooner than current "
+                                         "best.", __func__, ccname);
+                       free(namelist[i]);
                        continue;
                }
-               p += 11;
-               left -= 11;
-               value = SMB_STRNDUP(p, left);
-               break;
+
+               syslog(LOG_DEBUG, "%s: %s is valid ccache", __func__, ccname);
+               free(best_cache);
+               best_cache = SMB_STRNDUP(ccname, MAX_CCNAME_LEN);
+               best_time = cred_time;
+               free(namelist[i]);
        }
-       return value;
+       free(namelist);
+
+       return best_cache;
 }
 
 /*
@@ -105,7 +212,7 @@ get_krb5_ccname(pid_t pid)
  *     sess_key-       pointer for SessionKey data to be stored
  *
  * ret: 0 - success, others - failure
-*/
+ */
 static int
 handle_krb5_mech(const char *oid, const char *principal, DATA_BLOB *secblob,
                 DATA_BLOB *sess_key, const char *ccname)
@@ -113,12 +220,20 @@ handle_krb5_mech(const char *oid, const char *principal, DATA_BLOB *secblob,
        int retval;
        DATA_BLOB tkt, tkt_wrapped;
 
+       syslog(LOG_DEBUG, "%s: getting service ticket for %s", __func__,
+                         principal);
+
        /* get a kerberos ticket for the service and extract the session key */
        retval = cli_krb5_get_ticket(principal, 0, &tkt, sess_key, 0, ccname,
-                                    NULL);
+                                    NULL, NULL);
 
-       if (retval)
+       if (retval) {
+               syslog(LOG_DEBUG, "%s: failed to obtain service ticket (%d)",
+                                 __func__, retval);
                return retval;
+       }
+
+       syslog(LOG_DEBUG, "%s: obtained service ticket", __func__);
 
        /* wrap that up in a nice GSS-API wrapping */
        tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
@@ -131,19 +246,27 @@ handle_krb5_mech(const char *oid, const char *principal, DATA_BLOB *secblob,
        return retval;
 }
 
-#define DKD_HAVE_HOSTNAME      1
-#define DKD_HAVE_VERSION       2
-#define DKD_HAVE_SEC           4
-#define DKD_HAVE_IPV4          8
-#define DKD_HAVE_IPV6          16
-#define DKD_HAVE_UID           32
-#define DKD_HAVE_PID           64
+#define DKD_HAVE_HOSTNAME      0x1
+#define DKD_HAVE_VERSION       0x2
+#define DKD_HAVE_SEC           0x4
+#define DKD_HAVE_IP            0x8
+#define DKD_HAVE_UID           0x10
+#define DKD_HAVE_PID           0x20
 #define DKD_MUSTHAVE_SET (DKD_HAVE_HOSTNAME|DKD_HAVE_VERSION|DKD_HAVE_SEC)
 
-static int
-decode_key_description(const char *desc, int *ver, secType_t *sec,
-                          char **hostname, uid_t *uid, pid_t *pid)
+struct decoded_args {
+       int             ver;
+       char            *hostname;
+       char            *ip;
+       uid_t           uid;
+       pid_t           pid;
+       sectype_t       sec;
+};
+
+static unsigned int
+decode_key_description(const char *desc, struct decoded_args *arg)
 {
+       int len;
        int retval = 0;
        char *pos;
        const char *tkn = desc;
@@ -151,27 +274,34 @@ decode_key_description(const char *desc, int *ver, secType_t *sec,
        do {
                pos = index(tkn, ';');
                if (strncmp(tkn, "host=", 5) == 0) {
-                       int len;
 
-                       if (pos == NULL) {
+                       if (pos == NULL)
                                len = strlen(tkn);
-                       } else {
+                       else
                                len = pos - tkn;
-                       }
+
                        len -= 4;
-                       SAFE_FREE(*hostname);
-                       *hostname = SMB_XMALLOC_ARRAY(char, len);
-                       strlcpy(*hostname, tkn + 5, len);
+                       SAFE_FREE(arg->hostname);
+                       arg->hostname = SMB_XMALLOC_ARRAY(char, len);
+                       strlcpy(arg->hostname, tkn + 5, len);
                        retval |= DKD_HAVE_HOSTNAME;
-               } else if (strncmp(tkn, "ipv4=", 5) == 0) {
-                       /* BB: do we need it if we have hostname already? */
-               } else if (strncmp(tkn, "ipv6=", 5) == 0) {
-                       /* BB: do we need it if we have hostname already? */
+               } else if (!strncmp(tkn, "ip4=", 4) ||
+                          !strncmp(tkn, "ip6=", 4)) {
+                       if (pos == NULL)
+                               len = strlen(tkn);
+                       else
+                               len = pos - tkn;
+
+                       len -= 3;
+                       SAFE_FREE(arg->ip);
+                       arg->ip = SMB_XMALLOC_ARRAY(char, len);
+                       strlcpy(arg->ip, tkn + 4, len);
+                       retval |= DKD_HAVE_IP;
                } else if (strncmp(tkn, "pid=", 4) == 0) {
                        errno = 0;
-                       *pid = strtol(tkn + 4, NULL, 0);
+                       arg->pid = strtol(tkn + 4, NULL, 0);
                        if (errno != 0) {
-                               syslog(LOG_WARNING, "Invalid pid format: %s",
+                               syslog(LOG_ERR, "Invalid pid format: %s",
                                       strerror(errno));
                                return 1;
                        } else {
@@ -180,16 +310,16 @@ decode_key_description(const char *desc, int *ver, secType_t *sec,
                } else if (strncmp(tkn, "sec=", 4) == 0) {
                        if (strncmp(tkn + 4, "krb5", 4) == 0) {
                                retval |= DKD_HAVE_SEC;
-                               *sec = KRB5;
+                               arg->sec = KRB5;
                        } else if (strncmp(tkn + 4, "mskrb5", 6) == 0) {
                                retval |= DKD_HAVE_SEC;
-                               *sec = MS_KRB5;
+                               arg->sec = MS_KRB5;
                        }
                } else if (strncmp(tkn, "uid=", 4) == 0) {
                        errno = 0;
-                       *uid = strtol(tkn + 4, NULL, 16);
+                       arg->uid = strtol(tkn + 4, NULL, 16);
                        if (errno != 0) {
-                               syslog(LOG_WARNING, "Invalid uid format: %s",
+                               syslog(LOG_ERR, "Invalid uid format: %s",
                                       strerror(errno));
                                return 1;
                        } else {
@@ -197,10 +327,9 @@ decode_key_description(const char *desc, int *ver, secType_t *sec,
                        }
                } else if (strncmp(tkn, "ver=", 4) == 0) {      /* if version */
                        errno = 0;
-                       *ver = strtol(tkn + 4, NULL, 16);
+                       arg->ver = strtol(tkn + 4, NULL, 16);
                        if (errno != 0) {
-                               syslog(LOG_WARNING,
-                                      "Invalid version format: %s",
+                               syslog(LOG_ERR, "Invalid version format: %s",
                                       strerror(errno));
                                return 1;
                        } else {
@@ -226,7 +355,7 @@ cifs_resolver(const key_serial_t key, const char *key_descr)
        for (c = 1; c <= 4; c++) {
                keyend = index(keyend+1, ';');
                if (!keyend) {
-                       syslog(LOG_WARNING, "invalid key description: %s",
+                       syslog(LOG_ERR, "invalid key description: %s",
                                        key_descr);
                        return 1;
                }
@@ -236,20 +365,19 @@ cifs_resolver(const key_serial_t key, const char *key_descr)
        /* resolve name to ip */
        c = getaddrinfo(keyend, NULL, NULL, &addr);
        if (c) {
-               syslog(LOG_WARNING, "unable to resolve hostname: %s [%s]",
+               syslog(LOG_ERR, "unable to resolve hostname: %s [%s]",
                                keyend, gai_strerror(c));
                return 1;
        }
 
        /* conver ip to string form */
-       if (addr->ai_family == AF_INET) {
+       if (addr->ai_family == AF_INET)
                p = &(((struct sockaddr_in *)addr->ai_addr)->sin_addr);
-       } else {
+       else
                p = &(((struct sockaddr_in6 *)addr->ai_addr)->sin6_addr);
-       }
+
        if (!inet_ntop(addr->ai_family, p, ip, sizeof(ip))) {
-               syslog(LOG_WARNING, "%s: inet_ntop: %s",
-                               __FUNCTION__, strerror(errno));
+               syslog(LOG_ERR, "%s: inet_ntop: %s", __func__, strerror(errno));
                freeaddrinfo(addr);
                return 1;
        }
@@ -257,8 +385,8 @@ cifs_resolver(const key_serial_t key, const char *key_descr)
        /* setup key */
        c = keyctl_instantiate(key, ip, strlen(ip)+1, 0);
        if (c == -1) {
-               syslog(LOG_WARNING, "%s: keyctl_instantiate: %s",
-                               __FUNCTION__, strerror(errno));
+               syslog(LOG_ERR, "%s: keyctl_instantiate: %s", __func__,
+                               strerror(errno));
                freeaddrinfo(addr);
                return 1;
        }
@@ -267,45 +395,106 @@ cifs_resolver(const key_serial_t key, const char *key_descr)
        return 0;
 }
 
+/*
+ * Older kernels sent IPv6 addresses without colons. Well, at least
+ * they're fixed-length strings. Convert these addresses to have colon
+ * delimiters to make getaddrinfo happy.
+ */
+static void
+convert_inet6_addr(const char *from, char *to)
+{
+       int i = 1;
+
+       while (*from) {
+               *to++ = *from++;
+               if (!(i++ % 4) && *from)
+                       *to++ = ':';
+       }
+       *to = 0;
+}
+
+static int
+ip_to_fqdn(const char *addrstr, char *host, size_t hostlen)
+{
+       int rc;
+       struct addrinfo hints = { .ai_flags = AI_NUMERICHOST };
+       struct addrinfo *res;
+       const char *ipaddr = addrstr;
+       char converted[INET6_ADDRSTRLEN + 1];
+
+       if ((strlen(ipaddr) > INET_ADDRSTRLEN) && !strchr(ipaddr, ':')) {
+               convert_inet6_addr(ipaddr, converted);
+               ipaddr = converted;
+       }
+
+       rc = getaddrinfo(ipaddr, NULL, &hints, &res);
+       if (rc) {
+               syslog(LOG_DEBUG, "%s: failed to resolve %s to "
+                       "ipaddr: %s", __func__, ipaddr,
+               rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
+               return rc;
+       }
+
+       rc = getnameinfo(res->ai_addr, res->ai_addrlen, host, hostlen,
+                        NULL, 0, NI_NAMEREQD);
+       freeaddrinfo(res);
+       if (rc) {
+               syslog(LOG_DEBUG, "%s: failed to resolve %s to fqdn: %s",
+                       __func__, ipaddr,
+                       rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
+               return rc;
+       }
+
+       syslog(LOG_DEBUG, "%s: resolved %s to %s", __func__, ipaddr, host);
+       return 0;
+}
+
 static void
 usage(void)
 {
-       syslog(LOG_WARNING, "Usage: %s [-c] [-v] key_serial", prog);
-       fprintf(stderr, "Usage: %s [-c] [-v] key_serial\n", prog);
+       syslog(LOG_INFO, "Usage: %s [-t] [-v] key_serial", prog);
+       fprintf(stderr, "Usage: %s [-t] [-v] key_serial\n", prog);
 }
 
+const struct option long_options[] = {
+       { "trust-dns",  0, NULL, 't' },
+       { "version",    0, NULL, 'v' },
+       { NULL,         0, NULL, 0 }
+};
+
 int main(const int argc, char *const argv[])
 {
        struct cifs_spnego_msg *keydata = NULL;
        DATA_BLOB secblob = data_blob_null;
        DATA_BLOB sess_key = data_blob_null;
-       secType_t sectype = NONE;
        key_serial_t key = 0;
        size_t datalen;
+       unsigned int have;
        long rc = 1;
-       uid_t uid = 0;
-       pid_t pid = 0;
-       int kernel_upcall_version = 0;
-       int c, use_cifs_service_prefix = 0;
-       char *buf, *ccname = NULL, *hostname = NULL;
+       int c, try_dns = 0;
+       char *buf, *princ = NULL, *ccname = NULL;
+       char hostbuf[NI_MAXHOST], *host;
+       struct decoded_args arg = { };
        const char *oid;
 
+       hostbuf[0] = '\0';
+
        openlog(prog, 0, LOG_DAEMON);
 
-       while ((c = getopt(argc, argv, "cv")) != -1) {
+       while ((c = getopt_long(argc, argv, "ctv", long_options, NULL)) != -1) {
                switch (c) {
-               case 'c':{
-                       use_cifs_service_prefix = 1;
+               case 'c':
+                       /* legacy option -- skip it */
                        break;
-                       }
-               case 'v':{
+               case 't':
+                       try_dns++;
+                       break;
+               case 'v':
                        printf("version: %s\n", CIFSSPNEGO_VERSION);
                        goto out;
-                       }
-               default:{
-                       syslog(LOG_WARNING, "unknown option: %c", c);
+               default:
+                       syslog(LOG_ERR, "unknown option: %c", c);
                        goto out;
-                       }
                }
        }
 
@@ -320,96 +509,108 @@ int main(const int argc, char *const argv[])
        key = strtol(argv[optind], NULL, 10);
        if (errno != 0) {
                key = 0;
-               syslog(LOG_WARNING, "Invalid key format: %s", strerror(errno));
+               syslog(LOG_ERR, "Invalid key format: %s", strerror(errno));
                goto out;
        }
 
        rc = keyctl_describe_alloc(key, &buf);
        if (rc == -1) {
-               syslog(LOG_WARNING, "keyctl_describe_alloc failed: %s",
+               syslog(LOG_ERR, "keyctl_describe_alloc failed: %s",
                       strerror(errno));
                rc = 1;
                goto out;
        }
 
+       syslog(LOG_DEBUG, "key description: %s", buf);
+
        if ((strncmp(buf, "cifs.resolver", sizeof("cifs.resolver")-1) == 0) ||
            (strncmp(buf, "dns_resolver", sizeof("dns_resolver")-1) == 0)) {
                rc = cifs_resolver(key, buf);
                goto out;
        }
 
-       rc = decode_key_description(buf, &kernel_upcall_version, &sectype,
-                                   &hostname, &uid, &pid);
-       if ((rc & DKD_MUSTHAVE_SET) != DKD_MUSTHAVE_SET) {
-               syslog(LOG_WARNING,
-                      "unable to get from description necessary params");
+       have = decode_key_description(buf, &arg);
+       SAFE_FREE(buf);
+       if ((have & DKD_MUSTHAVE_SET) != DKD_MUSTHAVE_SET) {
+               syslog(LOG_ERR, "unable to get necessary params from key "
+                               "description (0x%x)", have);
                rc = 1;
-               SAFE_FREE(buf);
                goto out;
        }
-       SAFE_FREE(buf);
 
-       if (kernel_upcall_version > CIFS_SPNEGO_UPCALL_VERSION) {
-               syslog(LOG_WARNING,
-                      "incompatible kernel upcall version: 0x%x",
-                      kernel_upcall_version);
+       if (arg.ver > CIFS_SPNEGO_UPCALL_VERSION) {
+               syslog(LOG_ERR, "incompatible kernel upcall version: 0x%x",
+                               arg.ver);
                rc = 1;
                goto out;
        }
 
-       if (rc & DKD_HAVE_PID)
-               ccname = get_krb5_ccname(pid);
-
-       if (rc & DKD_HAVE_UID) {
-               rc = setuid(uid);
+       if (have & DKD_HAVE_UID) {
+               rc = setuid(arg.uid);
                if (rc == -1) {
-                       syslog(LOG_WARNING, "setuid: %s", strerror(errno));
+                       syslog(LOG_ERR, "setuid: %s", strerror(errno));
                        goto out;
                }
+
+               ccname = find_krb5_cc(CIFS_DEFAULT_KRB5_DIR, arg.uid);
        }
 
+       host = arg.hostname;
+
        // do mech specific authorization
-       switch (sectype) {
+       switch (arg.sec) {
        case MS_KRB5:
-       case KRB5:{
-                       char *princ;
-                       size_t len;
-
-                       /* for "cifs/" service name + terminating 0 */
-                       len = strlen(hostname) + 5 + 1;
-                       princ = SMB_XMALLOC_ARRAY(char, len);
-                       if (!princ) {
-                               rc = 1;
-                               break;
-                       }
-                       if (use_cifs_service_prefix) {
-                               strlcpy(princ, "cifs/", len);
-                       } else {
-                               strlcpy(princ, "host/", len);
-                       }
-                       strlcpy(princ + 5, hostname, len - 5);
+       case KRB5:
+retry_new_hostname:
+               /* for "cifs/" service name + terminating 0 */
+               datalen = strlen(host) + 5 + 1;
+               princ = SMB_XMALLOC_ARRAY(char, datalen);
+               if (!princ) {
+                       rc = -ENOMEM;
+                       break;
+               }
 
-                       if (sectype == MS_KRB5)
-                               oid = OID_KERBEROS5_OLD;
-                       else
-                               oid = OID_KERBEROS5;
+               if (arg.sec == MS_KRB5)
+                       oid = OID_KERBEROS5_OLD;
+               else
+                       oid = OID_KERBEROS5;
+
+               /*
+                * try getting a cifs/ principal first and then fall back to
+                * getting a host/ principal if that doesn't work.
+                */
+               strlcpy(princ, "cifs/", datalen);
+               strlcpy(princ + 5, host, datalen - 5);
+               rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
+               if (!rc)
+                       break;
 
-                       rc = handle_krb5_mech(oid, princ, &secblob, &sess_key,
-                                             ccname);
-                       SAFE_FREE(princ);
+               memcpy(princ, "host/", 5);
+               rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
+               if (!rc)
                        break;
-               }
-       default:{
-                       syslog(LOG_WARNING, "sectype: %d is not implemented",
-                              sectype);
-                       rc = 1;
+
+               if (!try_dns || !(have & DKD_HAVE_IP))
                        break;
-               }
+
+               rc = ip_to_fqdn(arg.ip, hostbuf, sizeof(hostbuf));
+               if (rc)
+                       break;
+
+               SAFE_FREE(princ);
+               try_dns = 0;
+               host = hostbuf;
+               goto retry_new_hostname;
+       default:
+               syslog(LOG_ERR, "sectype: %d is not implemented", arg.sec);
+               rc = 1;
+               break;
        }
 
-       if (rc) {
+       SAFE_FREE(princ);
+
+       if (rc)
                goto out;
-       }
 
        /* pack SecurityBLob and SessionKey into downcall packet */
        datalen =
@@ -419,7 +620,7 @@ int main(const int argc, char *const argv[])
                rc = 1;
                goto out;
        }
-       keydata->version = kernel_upcall_version;
+       keydata->version = arg.ver;
        keydata->flags = 0;
        keydata->sesskey_len = sess_key.length;
        keydata->secblob_len = secblob.length;
@@ -430,7 +631,7 @@ int main(const int argc, char *const argv[])
        /* setup key */
        rc = keyctl_instantiate(key, keydata, datalen, 0);
        if (rc == -1) {
-               syslog(LOG_WARNING, "keyctl_instantiate: %s", strerror(errno));
+               syslog(LOG_ERR, "keyctl_instantiate: %s", strerror(errno));
                goto out;
        }
 
@@ -448,7 +649,8 @@ out:
        data_blob_free(&secblob);
        data_blob_free(&sess_key);
        SAFE_FREE(ccname);
-       SAFE_FREE(hostname);
+       SAFE_FREE(arg.hostname);
+       SAFE_FREE(arg.ip);
        SAFE_FREE(keydata);
        return rc;
 }