From: J. Ali Harlow <ali@juiblex.co.uk>
Date: Sat, 14 Feb 2009 11:35:32 +0000 (+0000)
Subject: Refactor run_script for improved readability
X-Git-Tag: 0.1~25
X-Git-Url: http://project.juiblex.co.uk/git/?a=commitdiff_plain;h=f78e7d58d56439b7e6f7ba076e22f09937b69156;p=razor2.git%2F.git

Refactor run_script for improved readability
---

diff --git a/librazor/rpm.c b/librazor/rpm.c
index 8ca7bdd..51acc52 100644
--- a/librazor/rpm.c
+++ b/librazor/rpm.c
@@ -736,25 +736,76 @@ create_path(struct installer *installer, const char *path, unsigned int mode)
 	}
 }
 
-static int
-run_script(struct installer *installer,
-	   unsigned int program_tag, unsigned int script_tag)
+static int chroot_push(const char *root)
 {
+	int fd;
 #if HAVE_CHROOT
-	int pid, status, fd[2];
-#if HAVE_LUA
-	int save_root, retval;
+	if (geteuid() == 0) {
+		fd = open("/", O_RDONLY, 0);
+		if (chroot(root) < 0) {
+			fprintf(stderr, "failed to chroot to %s: %s\n",
+				root, strerror(errno));
+			exit(-1);
+		}
+	} else
+#endif
+		fd = -1;
+	return fd;
+}
+
+static void chroot_pop(int fd)
+{
+#if HAVE_CHROOT
+	if (fd >= 0) {
+		fchdir(fd);
+		close(fd);
+		chroot(".");
+	}
 #endif
-#else	/* HAVE_CHROOT */
+}
+
+static int
+run_script_lua(const char *root, unsigned int script_tag, const char *script)
+{
+	int root_fd, retval;
+#if HAVE_LUA
+	const char *name;
+
+	switch(script_tag) {
+		case RPMTAG_PREIN:
+			name = "%pre";
+			break;
+		case RPMTAG_POSTIN:
+			name = "%post";
+			break;
+		case RPMTAG_PREUN:
+			name = "%preun";
+			break;
+		case RPMTAG_POSTUN:
+			name = "%postun";
+			break;
+		default:
+			name = "script";
+			break;
+	}
+	root_fd = chroot_push(root);
+	retval = run_lua_script(root_fd < 0 ? root : NULL, name, script, -1);
+	chroot_pop(root_fd);
+#else	/* HAVE_LUA */
+	fprintf(stderr, "lua not available to run script\n");
+	retval = -1;
+#endif	/* HAVE_LUA */
+
+	return retval;
+}
+
+static int
+run_script_external(const char *root, const char *program, const char *script)
+{
+	int root_fd, retval;
 	FILE *fp;
-#endif	/* HAVE_CHROOT */
-	const char *script = NULL, *program = NULL;
 
-	program = razor_rpm_get_indirect(installer->rpm, program_tag, NULL);
-	script = razor_rpm_get_indirect(installer->rpm, script_tag, NULL);
-	if (program == NULL && script == NULL) {
-		return 0;
-	} else if (program == NULL) {
+	if (program == NULL) {
 #if MSWIN_API
 		program = getenv("COMSPEC");
 		if (program) {
@@ -767,107 +818,44 @@ run_script(struct installer *installer,
 #else
 		program = "/bin/sh";
 #endif
-	} else if (!strcmp(program, "<lua>")) {
-#if HAVE_LUA
-		const char *name;
-
-		switch(script_tag) {
-			case RPMTAG_PREIN:
-				name = "%pre";
-				break;
-			case RPMTAG_POSTIN:
-				name = "%post";
-				break;
-			case RPMTAG_PREUN:
-				name = "%preun";
-				break;
-			case RPMTAG_POSTUN:
-				name = "%postun";
-				break;
-			default:
-				name = "script";
-				break;
-		}
-#if HAVE_CHROOT
-		if (geteuid() == 0) {
-			save_root = open("/", O_RDONLY, 0);
-			if (chroot(installer->root) < 0) {
-				fprintf(stderr, "failed to chroot to %s: %s\n",
-					installer->root, strerror(errno));
-				exit(-1);
-			}
-			retval = run_lua_script(NULL, name, script, -1);
-			fchdir(save_root);
-			close(save_root);
-			chroot(".");
-		} else
-#endif
-		{
-			retval = run_lua_script(installer->root, name, script,
-						-1);
-		}
-		return retval;
-#else	/* HAVE_LUA */
-		fprintf(stderr, "lua not available to run script\n");
-		return -1;
-#endif	/* HAVE_LUA */
 	}
 
-#if HAVE_CHROOT
-	if (pipe(fd) < 0) {
-		fprintf(stderr, "failed to create pipe\n");
-		return -1;
-	}
-	pid = fork();
-	if (pid < 0) {
-		perror("failed to fork");
-	} else if (pid == 0) {
-		if (dup2(fd[0], STDIN_FILENO) < 0) {
-			perror("failed redirect stdin");
-			exit(-1);
-		}
-		if (close(fd[0]) < 0 || close(fd[1]) < 0) {
-			perror("failed to close pipe");
-			exit(-1);
-		}
-		if (chroot(installer->root) < 0) {
-			fprintf(stderr, "failed to chroot to %s: %s\n",
-				installer->root, strerror(errno));
-			exit(-1);
-		}
-		printf("executing program %s in chroot %s\n",
-		       program, installer->root);
-		if (execl(program, program, NULL)) {
-			fprintf(stderr, "failed to exec %s: %s\n", program,
-				strerror(errno));
-			exit(-1);
-		}
-	} else {
-		if (script && razor_write(fd[1], script, strlen(script)) < 0) {
-			perror("failed to pipe script");
-			return -1;
-		}
-		if (close(fd[0]) || close(fd[1])) {
-			perror("failed to close pipe");
-			return -1;
-		}
-		if (wait(&status) < 0) {
-			perror("wait for child failed");
-			return -1;
-		}
-		if (status)
-			printf("script exited with status %d\n", status);
-	}
-#else
+	root_fd = chroot_push(root);
 	fp = popen(program, "w");
-	if (fwrite(script, strlen(script), 1, fp) != 1) {
-		perror("failed to pipe script");
-		return -1;
-	}
-	pclose(fp);
-#endif
 
-	return 0;
+	if (!fp) {
+		perror(program);
+		retval = -1;
+	} else if (fwrite(script, strlen(script), 1, fp) != 1) {
+		perror("failed to write script to program");
+		retval = -1;
+	} else
+		retval = 0;
+
+	if (fp)
+		pclose(fp);
+	chroot_pop(root_fd);
+
+	return retval;
+}
+
+static int
+run_script(struct installer *installer,
+	   unsigned int program_tag, unsigned int script_tag)
+{
+	int retval;
+	const char *script = NULL, *program = NULL;
+
+	program = razor_rpm_get_indirect(installer->rpm, program_tag, NULL);
+	script = razor_rpm_get_indirect(installer->rpm, script_tag, NULL);
+	if (program == NULL && script == NULL)
+		retval = 0;
+	else if (strcmp(program, "<lua>") == 0)
+		retval = run_script_lua(installer->root, script_tag, script);
+	else
+		retval = run_script_external(installer->root, program, script);
+
+	return retval;
 }
 
 static int