From 6bb9c4e01fd8a032f8c8aaad2b2f35aca7814c4e Mon Sep 17 00:00:00 2001
From: Vincent Bernat <bernat@luffy.cx>
Date: Tue, 29 Sep 2009 17:10:10 +0200
Subject: [PATCH] Add support for libc not defining __progname symbol.

This may happen with ancient releases of uClibc.
---
 configure.ac   |  1 +
 m4/progname.m4 | 14 ++++++++++++++
 src/agent.c    |  4 ++++
 src/lldpctl.c  | 10 +++++++---
 src/lldpd.c    |  8 ++++++--
 src/lldpd.h    |  2 +-
 src/log.c      |  6 ++----
 7 files changed, 35 insertions(+), 10 deletions(-)
 create mode 100644 m4/progname.m4

diff --git a/configure.ac b/configure.ac
index 99ca1401..fba0ae1a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -116,6 +116,7 @@ AC_TYPE_SSIZE_T
 AC_TYPE_UINT16_T
 AC_TYPE_UINT32_T
 AC_TYPE_UINT8_T
+lldp_CHECK___PROGNAME
 
 # Checks for library functions.
 AC_FUNC_CHOWN
diff --git a/m4/progname.m4 b/m4/progname.m4
new file mode 100644
index 00000000..28ac1748
--- /dev/null
+++ b/m4/progname.m4
@@ -0,0 +1,14 @@
+#
+# lldp_CHECK___PROGNAME
+#
+AC_DEFUN([lldp_CHECK___PROGNAME],[
+  AC_CACHE_CHECK([whether libc defines __progname], lldp_cv_check___progname, [
+    AC_TRY_LINK([],
+	[ extern char *__progname; printf("%s", __progname); ],
+	[ lldp_cv_check___progname="yes" ],
+	[ lldp_cv_check___progname="no" ])
+  ])
+  if test x"$lldp_cv_check___progname" = x"yes"; then
+     AC_DEFINE([HAVE___PROGNAME], [1], [Define if libc defines __progname])
+  fi
+])
diff --git a/src/agent.c b/src/agent.c
index 01b50a18..a1bfc8f9 100644
--- a/src/agent.c
+++ b/src/agent.c
@@ -1262,7 +1262,11 @@ void
 agent_init(struct lldpd *cfg, int debug)
 {
 	int rc;
+#ifdef HAVE___PROGNAME
 	extern char *__progname;
+#else
+#  define __progname "lldpd"
+#endif
 
 	LLOG_INFO("Enable SNMP subagent");
 	netsnmp_enable_subagent();
diff --git a/src/lldpctl.c b/src/lldpctl.c
index e0509a39..92256115 100644
--- a/src/lldpctl.c
+++ b/src/lldpctl.c
@@ -35,6 +35,12 @@ TAILQ_HEAD(vlans, lldpd_vlan);
 	    (unsigned int)ntohl(((int)(x >> 32))))
 #define htonll(x) ntohll(x)
 
+#ifdef HAVE___PROGNAME
+extern const char	*__progname;
+#else
+# define __progname "lldpctl"
+#endif
+
 
 struct value_string {
 	int value;
@@ -131,8 +137,6 @@ static const struct value_string operational_mau_type_values[] = {
 static void
 usage(void)
 {
-	extern const char	*__progname;
-
 	fprintf(stderr, "usage: %s [options]\n", __progname);
 	fprintf(stderr, "see manual page lldpctl(8) for more information\n");
 	exit(1);
@@ -1150,7 +1154,7 @@ main(int argc, char *argv[])
 		}
 	}		
 	
-	log_init(debug);
+	log_init(debug, __progname);
 	
 	if ((s = ctl_connect(LLDPD_CTL_SOCKET)) == -1)
 		fatalx("unable to connect to socket " LLDPD_CTL_SOCKET);
diff --git a/src/lldpd.c b/src/lldpd.c
index 2d1b336a..be643252 100644
--- a/src/lldpd.c
+++ b/src/lldpd.c
@@ -86,11 +86,15 @@ static void		 lldpd_med(struct lldpd_chassis *);
 #endif
 
 static char		**saved_argv;
+#ifdef HAVE___PROGNAME
+extern const char	*__progname;
+#else
+# define __progname "lldpd"
+#endif
 
 static void
 usage(void)
 {
-	extern const char	*__progname;
 	fprintf(stderr, "usage: %s [options]\n", __progname);
 	fprintf(stderr, "see manual page lldpd(8) for more information\n");
 	exit(1);
@@ -811,7 +815,7 @@ lldpd_main(int argc, char *argv[])
 		}
 	}
 	
-	log_init(debug);
+	log_init(debug, __progname);
 
 	if (!debug) {
 		int pid;
diff --git a/src/lldpd.h b/src/lldpd.h
index 7ec53642..4db9a07e 100644
--- a/src/lldpd.h
+++ b/src/lldpd.h
@@ -414,7 +414,7 @@ char	*dmi_asset(void);
 #endif
 
 /* log.c */
-void             log_init(int);
+void             log_init(int, const char *);
 void             log_warn(const char *, ...);
 #define LLOG_WARN(x,...) log_warn("%s: " x, __FUNCTION__ , ## __VA_ARGS__)
 void             log_warnx(const char *, ...);
diff --git a/src/log.c b/src/log.c
index 3f85eda9..8e0c0de4 100644
--- a/src/log.c
+++ b/src/log.c
@@ -32,14 +32,12 @@ static void	 vlog(int, const char *, va_list);
 static void	 logit(int, const char *, ...);
 
 void
-log_init(int n_debug)
+log_init(int n_debug, const char *progname)
 {
-	extern char	*__progname;
-
 	debug = n_debug;
 
 	if (!debug)
-		openlog(__progname, LOG_PID | LOG_NDELAY, LOG_DAEMON);
+		openlog(progname, LOG_PID | LOG_NDELAY, LOG_DAEMON);
 
 	tzset();
 }
-- 
2.39.5