ifupdown: stop emitting annoying/misleading error messages.

Patch by Gabriel Somlo <somlo at cmu.edu>

debianutils/which.c

@@ -3,6 +3,7 @@
  * Which implementation for busybox
  *
  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
  *
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  *
@@ -10,74 +11,33 @@
  */
 
 #include "busybox.h"
-#include <string.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/stat.h>
-
-
-static int is_executable_file(char *a, struct stat *b)
-{
-	return (!access(a,X_OK) && !stat(a, b) && S_ISREG(b->st_mode));
-}
 
 int which_main(int argc, char **argv)
 {
-	int status;
-	size_t i, count;
-	char *path_list, *p;
+	int status = EXIT_SUCCESS;
+	char *p;
 
 	if (argc <= 1 || argv[1][0] == '-') {
 		bb_show_usage();
 	}
-	argc--;
-
-	path_list = getenv("PATH");
-	if (path_list != NULL) {
-		count = 1;
-		p = path_list;
-		while ((p = strchr(p, ':')) != NULL) {
-			*p++ = 0;
-			count++;
-		}
-	} else {
-		path_list = "/bin\0/sbin\0/usr/bin\0/usr/sbin\0/usr/local/bin";
-		count = 5;
-	}
-
-	status = EXIT_SUCCESS;
-	while (argc-- > 0) {
-		struct stat stat_b;
-		char *buf;
 
+	while (--argc > 0) {
 		argv++;
-		buf = argv[0];
-
-		/* If filename is either absolute or contains slashes,
-		 * stat it */
-		if (strchr(buf, '/')) {
-			if (is_executable_file(buf, &stat_b)) {
-				puts(buf);
-				goto next;
+		if (strchr(*argv, '/')) {
+			if (execable_file(*argv)) {
+				puts(*argv);
+				continue;
 			}
 		} else {
-			/* File doesn't contain slashes */
-			p = path_list;
-			for (i = 0; i < count; i++) {
-				/* Empty component in PATH is treated as . */
-				buf = concat_path_file(p[0] ? p : ".", argv[0]);
-				if (is_executable_file(buf, &stat_b)) {
-					puts(buf);
-					free(buf);
-					goto next;
-				}
-				free(buf);
-				p += strlen(p) + 1;
+			p = find_execable(*argv);
+			if (p) {
+				puts(p);
+				free(p);
+				continue;
 			}
 		}
 		status = EXIT_FAILURE;
- next:		/* nothing */;
 	}
+
 	bb_fflush_stdout_and_exit(status);
 }

include/libbb.h

@@ -430,6 +430,10 @@ char *last_char_is(const char *s, int c);
 
 char *fgets_str(FILE *file, const char *terminating_string);
 
+int execable_file(const char *name);
+char *find_execable(const char *filename);
+int exists_execable(const char *filename);
+
 extern USE_DESKTOP(long long) int uncompress(int fd_in, int fd_out);
 extern int inflate(int in, int out);
 

libbb/Kbuild

@@ -28,7 +28,7 @@ lib-y:= \
 	getopt32.o default_error_retval.o wfopen_input.o speed_table.o \
 	perror_nomsg_and_die.o perror_nomsg.o skip_whitespace.o bb_askpass.o \
 	warn_ignoring_args.o concat_subpath_file.o vfork_daemon_rexec.o \
-	bb_do_delay.o uuencode.o info_msg.o vinfo_msg.o
+	bb_do_delay.o uuencode.o info_msg.o vinfo_msg.o execable.o
 
 # conditionally compiled objects:
 lib-$(CONFIG_FEATURE_MOUNT_LOOP) += loop.o

networking/ifupdown.c

@@ -133,7 +133,7 @@ static int count_netmask_bits(char *dotted_quad)
 }
 #endif
 
-static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
+static void addstr(char **buf, size_t *len, size_t *pos, const char *str, size_t str_length)
 {
 	if (*pos + str_length >= *len) {
 		char *newbuf;
@@ -150,7 +150,7 @@ static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_l
 	(*buf)[*pos] = '\0';
 }
 
-static int strncmpz(char *l, char *r, size_t llen)
+static int strncmpz(const char *l, const char *r, size_t llen)
 {
 	int i = strncmp(l, r, llen);
 
@@ -161,7 +161,7 @@ static int strncmpz(char *l, char *r, size_t llen)
 	}
 }
 
-static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
+static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
 {
 	int i;
 
@@ -188,7 +188,7 @@ static char *get_var(char *id, size_t idlen, struct interface_defn_t *ifd)
 	return NULL;
 }
 
-static char *parse(char *command, struct interface_defn_t *ifd)
+static char *parse(const char *command, struct interface_defn_t *ifd)
 {
 
 	char *result = NULL;
@@ -294,7 +294,7 @@ static char *parse(char *command, struct interface_defn_t *ifd)
 }
 
 /* execute() returns 1 for success and 0 for failure */
-static int execute(char *command, struct interface_defn_t *ifd, execfn *exec)
+static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
 {
 	char *out;
 	int ret;
@@ -449,43 +449,65 @@ static int static_down(struct interface_defn_t *ifd, execfn *exec)
 	return ((result == 2) ? 2 : 0);
 }
 
+#ifndef CONFIG_APP_UDHCPC
+struct dhcp_client_t
+{
+	const char *name;
+	const char *startcmd;
+	const char *stopcmd;
+};
+
+static const struct dhcp_client_t ext_dhcp_clients[] = {
+	{ "udhcpc",
+		"udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
+		"kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
+	},
+	{ "pump",
+		"pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
+		"pump -i %iface% -k",
+	},
+	{ "dhclient",
+		"dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
+		"kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
+	},
+	{ "dhcpcd",
+		"dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l %leasetime%]] %iface%",
+		"dhcpcd -k %iface%",
+	},
+};
+#endif
+
 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
 {
-	if (execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid -i %iface% "
-			"[[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]", ifd, exec))
-		return 1;
-
-	/* 2006-09-30: The following are deprecated, and should eventually be
-	 * removed. For non-busybox (i.e., other than udhcpc) clients, use
-	 * 'iface foo inet manual' in /etc/network/interfaces, and supply
-	 * start/stop commands explicitly via up/down. */
-
-	if (execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]",
-			ifd, exec)) return 1;
-	if (execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
-			ifd, exec)) return 1;
-	if (execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] "
-			"[[-l %leasetime%]] %iface%", ifd, exec)) return 1;
-
+#ifdef CONFIG_APP_UDHCPC
+	return execute("udhcpc -R -n -p /var/run/udhcpc.%iface%.pid "
+			"-i %iface% [[-H %hostname%]] [[-c %clientid%]] [[-s %script%]]",
+			ifd, exec);
+#else
+	int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
+	for (i = 0; i < nclients; i++) {
+		if (exists_execable(ext_dhcp_clients[i].name))
+			return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
+	}
+	bb_error_msg("no dhcp clients found");
 	return 0;
+#endif
 }
 
 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
 {
-	if (execute("kill -TERM `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
-			ifd, exec)) return 1;
-
-	/* 2006-09-30: The following are deprecated, and should eventually be
-	 * removed. For non-busybox (i.e., other than udhcpc) clients, use
-	 * 'iface foo inet manual' in /etc/network/interfaces, and supply
-	 * start/stop commands explicitly via up/down. */
-
-	if (execute("pump -i %iface% -k", ifd, exec)) return 1;
-	if (execute("kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
-			ifd, exec)) return 1;
-	if (execute("dhcpcd -k %iface%", ifd, exec)) return 1;
-
+#ifdef CONFIG_APP_UDHCPC
+	return execute("kill -TERM "
+	               "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
+#else
+	int i, nclients = sizeof(ext_dhcp_clients) / sizeof(ext_dhcp_clients[0]);
+	for (i = 0; i < nclients; i++) {
+		if (exists_execable(ext_dhcp_clients[i].name))
+			return execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
+	}
+	bb_error_msg("no dhcp clients found, using static interface shutdown");
 	return static_down(ifd, exec);
+#endif
 }
 
 static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)