From c8e27b6f334931d5a609af6b50c9e0756e88b672 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn@samba.org>
Date: Fri, 2 Nov 2018 18:04:28 +0100
Subject: [PATCH] lib:replace: Add getprogname()

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---
 lib/replace/replace.c | 71 +++++++++++++++++++++++++++++++++++++++++++
 lib/replace/replace.h |  5 +++
 lib/replace/wscript   |  1 +
 3 files changed, 77 insertions(+)

diff --git a/lib/replace/replace.c b/lib/replace/replace.c
index 113137c2992..e38df98ea3a 100644
--- a/lib/replace/replace.c
+++ b/lib/replace/replace.c
@@ -978,3 +978,74 @@ int rep_memset_s(void *dest, size_t destsz, int ch, size_t count)
 	return 0;
 }
 #endif /* HAVE_MEMSET_S */
+
+#ifndef HAVE_GETPROGNAME
+# ifndef _GNU_SOURCE
+# define PROGNAME_SIZE 32
+static char rep_progname[PROGNAME_SIZE];
+# endif /* _GNU_SOURCE */
+
+const char *rep_getprogname(void)
+{
+#ifdef _GNU_SOURCE
+	return program_invocation_short_name;
+#else /* _GNU_SOURCE */
+	FILE *fp = NULL;
+	char cmdline[4096] = {0};
+	char *p = NULL;
+	pid_t pid;
+	size_t nread;
+	int len;
+
+	if (rep_progname[0] != '\0') {
+		return rep_progname;
+	}
+
+	len = snprintf(rep_progname, sizeof(rep_progname), "%s", "<unknown>");
+	if (len <= 0) {
+		return "<unknown>";
+	}
+
+	pid = getpid();
+	if (pid <= 1 || pid == (pid_t)-1) {
+		return rep_progname;
+	}
+
+	len = snprintf(cmdline,
+		       sizeof(cmdline),
+		       "/proc/%u/cmdline",
+		       (unsigned int)pid);
+	if (len <= 0 || len == sizeof(cmdline)) {
+		return rep_progname;
+	}
+
+	fp = fopen(cmdline, "r");
+	if (fp == NULL) {
+		return rep_progname;
+	}
+
+	nread = fread(cmdline, 1, sizeof(cmdline) - 1, fp);
+	if (nread == 0) {
+		return rep_progname;
+	}
+
+	cmdline[nread] = '\0';
+
+	p = strrchr(cmdline, '/');
+	if (p != NULL) {
+		p++;
+	} else {
+		p = cmdline;
+	}
+
+	len = strlen(p);
+	if (len > PROGNAME_SIZE) {
+		p[PROGNAME_SIZE - 1] = '\0';
+	}
+
+	(void)snprintf(rep_progname, sizeof(rep_progname), "%s", p);
+
+	return rep_progname;
+#endif /* _GNU_SOURCE */
+}
+#endif /* HAVE_GETPROGNAME */
diff --git a/lib/replace/replace.h b/lib/replace/replace.h
index de4e20c4454..732a8226858 100644
--- a/lib/replace/replace.h
+++ b/lib/replace/replace.h
@@ -933,6 +933,11 @@ void rep_setproctitle_init(int argc, char *argv[], char *envp[]);
 int rep_memset_s(void *dest, size_t destsz, int ch, size_t count);
 #endif
 
+#ifndef HAVE_GETPROGNAME
+#define getprogname rep_getprogname
+const char *rep_getprogname(void);
+#endif
+
 #ifndef FALL_THROUGH
 # ifdef HAVE_FALLTHROUGH_ATTRIBUTE
 #  define FALL_THROUGH __attribute__ ((fallthrough))
diff --git a/lib/replace/wscript b/lib/replace/wscript
index 8adfffe9584..c8693a3f2e1 100644
--- a/lib/replace/wscript
+++ b/lib/replace/wscript
@@ -426,6 +426,7 @@ def configure(conf):
     conf.CHECK_FUNCS('getgrent_r getgrgid_r getgrnam_r getgrouplist getpagesize')
     conf.CHECK_FUNCS('getpwent_r getpwnam_r getpwuid_r epoll_create')
     conf.CHECK_FUNCS('port_create')
+    conf.CHECK_FUNCS('getprogname')
 
     conf.SET_TARGET_TYPE('attr', 'EMPTY')
 
-- 
2.34.1