Relevant BUGIDs: 232194

Purpose of commit: new feature

Commit summary:
---------------
If you are looking for an object that you can blindly dlopen() and
use to bind to pam w/ modules, this commit is for you. Its not fully
integrated into the build tree, but I'd like some feedback before
wiring it in as a regular feature.

1 files changed, 180 insertions, 0 deletions

diff --git a/dynamic/pam.c b/dynamic/pam.c
new file mode 100644
index 00000000..6dd376c2
--- /dev/null
+++ b/dynamic/pam.c
@@ -0,0 +1,180 @@
+/*
+ * $Id$
+ *
+ * If you want to dynamically load libpam using dlopen() or something,
+ * then dlopen( ' this shared object ' ); It takes care of exporting
+ * the right symbols to any modules loaded by libpam.
+ */
+
+#include <stdio.h>
+#include <dlfcn.h>
+#include <security/pam_appl.h>
+#include <security/_pam_macros.h>
+
+#ifndef LIBPAMPATH
+#define LIBPAMPATH "/lib/libpam.so"
+#endif
+
+static void *libpam_h = NULL;
+
+#define CONFIRM_PAM_FUNCTION(x, y, z, err) \
+    do { \
+        union { const void *tpointer; y (*fn) z ; } fptr; \
+	fptr.tpointer = dlsym(libpam_h, #x); real_##x = fptr.fn; \
+	if (real_##x == NULL) { \
+	    D(("unable to resolve '" #x "': %s", dlerror())); \
+	    return err; \
+	} \
+    } while (0)
+
+
+extern void _init(void);
+
+void _init()
+{
+    if (libpam_h == NULL) {
+	libpam_h = dlopen(LIBPAMPATH, RTLD_GLOBAL|RTLD_NOW);
+    }
+}
+
+extern void _fini(void);
+
+void _fini()
+{
+    if (libpam_h != NULL) {
+	dlclose(libpam_h);
+    }
+}
+
+int pam_start(const char *service_name, const char *user,
+	      const struct pam_conv *pam_conversation,
+	      pam_handle_t **pamh)
+{
+    static int (*real_pam_start)(const char *, const char *,
+				 const struct pam_conv *,
+				 pam_handle_t **);
+    CONFIRM_PAM_FUNCTION(pam_start, int, (const char *, const char *,
+					  const struct pam_conv *,
+					  pam_handle_t **), PAM_ABORT);
+    return real_pam_start(service_name, user, pam_conversation, pamh);
+}
+
+int pam_end(pam_handle_t *pamh, int pam_status)
+{
+    static int (*real_pam_end)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_end, int, (pam_handle_t *, int), PAM_ABORT);
+    return real_pam_end(pamh, pam_status);
+}
+
+int pam_set_item(pam_handle_t *pamh, int item_type, const void *item)
+{
+    static int (*real_pam_set_item)(pam_handle_t *, int, const void *);
+    CONFIRM_PAM_FUNCTION(pam_set_item, int,
+			 (pam_handle_t *, int, const void *), PAM_ABORT);
+    return real_pam_set_item(pamh, item_type, item);
+}
+
+int pam_get_item(const pam_handle_t *pamh, int item_type, const void **item)
+{
+    static int (*real_pam_get_item)(const pam_handle_t *, int, const void **);
+    CONFIRM_PAM_FUNCTION(pam_get_item, int,
+			 (const pam_handle_t *, int, const void **),
+			 PAM_ABORT);
+    return real_pam_get_item(pamh, item_type, item);
+}
+
+int pam_fail_delay(pam_handle_t *pamh, unsigned int musec_delay)
+{
+    static int (*real_pam_fail_delay)(pam_handle_t *, unsigned int);
+    CONFIRM_PAM_FUNCTION(pam_fail_delay, int, (pam_handle_t *, unsigned int),
+			 PAM_ABORT);
+    return real_pam_fail_delay(pamh, musec_delay);
+}
+
+typedef const char * const_char_pointer;
+
+const_char_pointer pam_strerror(pam_handle_t *pamh, int errnum)
+{
+    static const_char_pointer (*real_pam_strerror)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_strerror, const_char_pointer,
+			 (pam_handle_t *, int), NULL);
+    return real_pam_strerror(pamh, errnum);
+}
+
+int pam_putenv(pam_handle_t *pamh, const char *name_value)
+{
+    static int (*real_pam_putenv)(pam_handle_t *, const char *);
+    CONFIRM_PAM_FUNCTION(pam_putenv, int, (pam_handle_t *, const char *),
+			 PAM_ABORT);
+    return real_pam_putenv(pamh, name_value);
+}
+
+const_char_pointer pam_getenv(pam_handle_t *pamh, const char *name)
+{
+    static const_char_pointer (*real_pam_getenv)(pam_handle_t *, const char *);
+    CONFIRM_PAM_FUNCTION(pam_getenv, const_char_pointer,
+			 (pam_handle_t *, const char *), NULL);
+    return real_pam_getenv(pamh, name);
+}
+
+typedef char ** char_ppointer;
+char_ppointer pam_getenvlist(pam_handle_t *pamh)
+{
+    static char_ppointer (*real_pam_getenvlist)(pam_handle_t *);
+    CONFIRM_PAM_FUNCTION(pam_getenvlist, char_ppointer, (pam_handle_t *),
+			 NULL);
+    return real_pam_getenvlist(pamh);
+}
+
+/* Authentication management */
+
+int pam_authenticate(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_authenticate)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_authenticate, int, (pam_handle_t *, int),
+			 PAM_ABORT);
+    return real_pam_authenticate(pamh, flags);
+}
+
+int pam_setcred(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_setcred)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_setcred, int, (pam_handle_t *, int), PAM_ABORT);
+    return real_pam_setcred(pamh, flags);
+}
+
+/* Account Management API's */
+
+int pam_acct_mgmt(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_acct_mgmt)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_acct_mgmt, int, (pam_handle_t *, int), PAM_ABORT);
+    return real_pam_acct_mgmt(pamh, flags);
+}
+
+/* Session Management API's */
+
+int pam_open_session(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_open_session)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_open_session, int, (pam_handle_t *, int),
+			 PAM_ABORT);
+    return real_pam_open_session(pamh, flags);
+}
+
+int pam_close_session(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_close_session)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_close_session, int, (pam_handle_t *, int),
+			 PAM_ABORT);
+    return real_pam_close_session(pamh, flags);
+}
+
+/* Password Management API's */
+
+int pam_chauthtok(pam_handle_t *pamh, int flags)
+{
+    static int (*real_pam_chauthtok)(pam_handle_t *, int);
+    CONFIRM_PAM_FUNCTION(pam_chauthtok, int, (pam_handle_t *, int), PAM_ABORT);
+    return real_pam_chauthtok(pamh, flags);
+}