From 802014dde0c3b25a48a4c6e5b09d20f52fb94324 Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Tue, 23 Apr 2013 17:47:20 -0700
Subject: [PATCH] Fix fips to work without requiring an absolute path for
 program to run.

With the latest commit that examines the ELF header of the program to
run fips was suddenly requiring that the absolute path of the program
be provided. This was obvisouly not desired.

It's simple enough to search through the PATH environment variable to
find the absolute path of the program to be run and examine that.
---
 execute.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/execute.c b/execute.c
index 8ce88e5..3ed645a 100644
--- a/execute.c
+++ b/execute.c
@@ -115,6 +115,55 @@ exists (const char *path)
 	return 1;
 }
 
+/* Given a program name, search the PATH environment variable and
+ * return the first absolute path to 'program'.
+ *
+ * Returns: A string talloc'ed to 'ctx'.
+ *
+ * Note: This function aborts the current program if 'program' cannot
+ * be located by searching PATH.
+ */
+static char *
+search_path_for_program (void *ctx, const char *program)
+{
+	char *orig_path, *path, *colon, *dir, *candidate;
+	void *local = talloc_new (ctx);
+
+	/* If the program name already contains a slash, then this is
+	 * an absolute (or relative) path. Either way, we don't search
+	 * PATH, since we can directly open this filename. */
+	if (strchr (program, '/'))
+	    return talloc_strdup (ctx, program);
+
+	orig_path = path = getenv ("PATH");
+
+	while (*path) {
+		colon = strchr (path, ':');
+
+		if (colon) {
+			dir = talloc_strndup (local, path, colon - path);
+			path = colon + 1;
+		} else {
+			dir = path;
+			path = path + strlen (path);
+		}
+
+		candidate = talloc_asprintf(local, "%s/%s", dir, program);
+
+		if (exists (candidate)) {
+			talloc_steal (ctx, candidate);
+			talloc_free (local);
+			return candidate;
+		} else {
+			talloc_free (candidate);
+		}
+	}
+
+	fprintf (stderr, "Cannot find program %s (looked in %s)\n",
+		 program, orig_path);
+	exit (1);
+}
+
 /* Is the given elf program 32 or 64 bit?
  *
  * Note: This function aborts the current program if 'program' cannot
@@ -125,10 +174,12 @@ elf_bits (const char *program)
 	Elf *elf;
 	GElf_Ehdr ehdr;
 	int fd, class;
+	void *local = talloc_new (NULL);
+	char *absolute_program = search_path_for_program (local, program);
 
-	fd = open (program, O_RDONLY, 0);
+	fd = open (absolute_program, O_RDONLY, 0);
 	if (fd < 0) {
-		fprintf (stderr, "Failed to open %s: %s\n", program,
+		fprintf (stderr, "Failed to open %s: %s\n", absolute_program,
 			 strerror (errno));
 		exit (1);
 	}
@@ -142,29 +193,31 @@ elf_bits (const char *program)
 	elf = elf_begin (fd, ELF_C_READ, NULL);
 	if (elf == NULL) {
 		fprintf (stderr, "Call to elf_begin on %s failed: %s\n",
-			 program, elf_errmsg(-1));
+			 absolute_program, elf_errmsg(-1));
 		exit (1);
 	}
 
 	if (elf_kind (elf) != ELF_K_ELF) {
-		fprintf (stderr, "Not an ELF object: %s\n", program);
+		fprintf (stderr, "Not an ELF object: %s\n", absolute_program);
 		exit (1);
 	}
 
 	if (gelf_getehdr (elf, &ehdr) == NULL) {
 		fprintf (stderr, "getehdr on %s failed: %s\n",
-			 program, elf_errmsg (-1));
+			 absolute_program, elf_errmsg (-1));
 		exit (1);
 	}
 
 	class = gelf_getclass (elf);
 
 	if (class == ELFCLASSNONE) {
-		fprintf (stderr, "getclass on %s failed: %s\n", program,
-			 elf_errmsg (-1));
+		fprintf (stderr, "getclass on %s failed: %s\n",
+			 absolute_program, elf_errmsg (-1));
 		exit (1);
 	}
 
+	talloc_free (local);
+
 	if (class == ELFCLASS32)
 		return 32;
 	else
-- 
2.43.0