[PATCH] cleanup callout fork

Here I change the callout fork logic.
The current cersion is unable to read a pipe which is not flushed at once,
Now we read until it's closed.

The maximum argument count is calculated by the strlen now. We have 100
chars for our result buffer so we can't have more than 50 parameters.
So it's much more clear what will happen now and not some magic boundary
where we use shell behind it.

Parameter can be combined to one by using apostrophes.

this on works now:
  BUS="scsi", PROGRAM="/bin/sh -c 'echo foo3 foo4 foo5 foo6 foo7 foo8 foo9 | sed  s/foo9/bar9/'", KERNEL="sda3", NAME="%c{7}"

Two new test are also added.

1 files changed, 48 insertions, 44 deletions

diff --git a/namedev.c b/namedev.c
index 1e424998f6..a9142374f4 100644
--- a/namedev.c
+++ b/namedev.c
@@ -370,22 +370,41 @@ static void fix_kernel_name(struct udevice *udev)
 static int execute_program(char *path, char *value, int len)
 {
 	int retval;
-	int res;
+	int count;
 	int status;
 	int fds[2];
 	pid_t pid;
-	int value_set = 0;
-	char buffer[255];
 	char *pos;
-	char *args[PROGRAM_MAXARG];
+	char arg[PROGRAM_SIZE];
+	char *argv[sizeof(arg) / 2];
 	int i;
 
-	dbg("executing '%s'", path);
+	i = 0;
+	if (strchr(path, ' ')) {
+		strfieldcpy(arg, path);
+		pos = arg;
+		while (pos != NULL) {
+			if (pos[0] == '\'') {
+				/* don't separate if in apostrophes */
+				pos++;
+				argv[i] = strsep(&pos, "\'");
+				while (pos[0] == ' ')
+					pos++;
+		} else {
+				argv[i] = strsep(&pos, " ");
+			}
+			dbg("arg[%i] '%s'", i, argv[i]);
+			i++;
+		}
+	}
+	argv[i] =  NULL;
+
 	retval = pipe(fds);
 	if (retval != 0) {
 		dbg("pipe failed");
 		return -1;
 	}
+
 	pid = fork();
 	switch(pid) {
 	case 0:
@@ -394,28 +413,14 @@ static int execute_program(char *path, char *value, int len)
 
 		/* dup write side of pipe to STDOUT */
 		dup(fds[1]);
-
-		/* copy off our path to use incase we have too many args */
-		strfieldcpymax(buffer, path, sizeof(buffer));
-
-		if (strchr(path, ' ')) {
-			/* exec with arguments */
-			pos = path;
-			for (i=0; i < PROGRAM_MAXARG-1; i++) {
-				args[i] = strsep(&pos, " ");
-				if (args[i] == NULL)
-					break;
-			}
-			if (args[i]) {
-				dbg("too many args - %d, using subshell instead '%s'", i, buffer);
-				retval = execl("/bin/sh", "sh", "-c", buffer, NULL);
-			} else {
-				dbg("execute program '%s'", path);
-				retval = execv(args[0], args);
-			}
+		if (argv[0] !=  NULL) {
+			dbg("execute '%s' with given arguments", argv[0]);
+			retval = execv(argv[0], argv);
 		} else {
+			dbg("execute '%s' with main argument", path);
 			retval = execv(path, main_argv);
 		}
+
 		info(FIELD_PROGRAM " execution of '%s' failed", path);
 		exit(1);
 	case -1:
@@ -425,34 +430,33 @@ static int execute_program(char *path, char *value, int len)
 		/* parent reads from fds[0] */
 		close(fds[1]);
 		retval = 0;
+		i = 0;
 		while (1) {
-			res = read(fds[0], buffer, sizeof(buffer) - 1);
-			if (res <= 0)
+			count = read(fds[0], value + i, len - i-1);
+			if (count <= 0)
 				break;
-			buffer[res] = '\0';
-			if (res > len) {
+
+			i += count;
+			if (i >= len-1) {
 				dbg("result len %d too short", len);
 				retval = -1;
-			}
-			if (value_set) {
-				dbg("result value already set");
-				retval = -1;
-			} else {
-				value_set = 1;
-				strncpy(value, buffer, len);
-				pos = value + strlen(value)-1;
-				if (pos[0] == '\n')
-					pos[0] = '\0';
-				dbg("result is '%s'", value);
+				break;
 			}
 		}
-		close(fds[0]);
-		res = wait(&status);
-		if (res < 0) {
-			dbg("wait failed result %d", res);
+
+		if (count < 0) {
+			dbg("read failed with '%s'", strerror(errno));
 			retval = -1;
 		}
 
+		if (i > 0 && value[i] == '\n')
+			i--;
+		value[i] = '\0';
+		dbg("result is '%s'", value);
+
+		close(fds[0]);
+		wait(&status);
+
 		if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
 			dbg("exec program status 0x%x", status);
 			retval = -1;
@@ -730,7 +734,7 @@ static int match_rule(struct config_device *dev, struct sysfs_class_device *clas
 			apply_format(udev, dev->program, sizeof(dev->program),
 				     class_dev, sysfs_device);
 			if (execute_program(dev->program, udev->program_result, NAME_SIZE) != 0) {
-				dbg(FIELD_PROGRAM " returned nozero");
+				dbg(FIELD_PROGRAM " returned nonzero");
 				goto try_parent;
 			} else {
 				dbg(FIELD_PROGRAM " returned successful");