chiark / gitweb /
[PATCH] cleanup callout fork
authorkay.sievers@vrfy.org <kay.sievers@vrfy.org>
Thu, 11 Mar 2004 09:36:12 +0000 (01:36 -0800)
committerGreg KH <gregkh@suse.de>
Wed, 27 Apr 2005 04:35:09 +0000 (21:35 -0700)
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.

namedev.c
namedev.h
test/udev-test.pl

index 1e42499..a914237 100644 (file)
--- 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");
index 16a8bff..68100d4 100644 (file)
--- a/namedev.h
+++ b/namedev.h
@@ -51,7 +51,6 @@ struct sysfs_class_device;
 #define ATTR_PARTITIONS                "all_partitions"
 #define PARTITIONS_COUNT       15
 
-#define PROGRAM_MAXARG         10
 #define MAX_SYSFS_PAIRS                5
 
 #define RULEFILE_EXT           ".rules"
index 38ea018..dadec56 100644 (file)
@@ -262,6 +262,24 @@ BUS="scsi", PROGRAM="/bin/echo -n foo3 foo4 foo5 foo6 foo7 foo8 foo9", KERNEL="s
 EOF
        },
        {
+               desc     => "program with subshell",
+               subsys   => "block",
+               devpath  => "block/sda/sda3",
+               expected => "bar9" ,
+               conf     => <<EOF
+BUS="scsi", PROGRAM="/bin/sh -c 'echo foo3 foo4 foo5 foo6 foo7 foo8 foo9 | sed  s/foo9/bar9/'", KERNEL="sda3", NAME="%c{7}"
+EOF
+       },
+       {
+               desc     => "program arguments combined with apostrophes",
+               subsys   => "block",
+               devpath  => "block/sda/sda3",
+               expected => "foo7" ,
+               conf     => <<EOF
+BUS="scsi", PROGRAM="/bin/echo -n 'foo3 foo4'   'foo5   foo6   foo7 foo8'", KERNEL="sda3", NAME="%c{5}"
+EOF
+       },
+       {
                desc     => "characters before the %c{N} substitution",
                subsys   => "block",
                devpath  => "block/sda/sda3",