[PATCH] add callout config type to udev

This patch adds a callout config type to udev, so external programs can be
called to get serial numbers or id's that are not available as a sysfs
attribute.

diff --git a/namedev.c b/namedev.c
index 782b73d0b9c8ce0add6b15ca1403646cf8a8231e..abed8685c8e7076af3d40c97a4a8af419fadde2c 100644 (file)
--- a/namedev.c
+++ b/namedev.c
@@ -31,6 +31,7 @@
 #include <ctype.h>
 #include <unistd.h>
 #include <errno.h>
+#include <sys/wait.h>
 
 #include "list.h"
 #include "udev.h"
@@ -42,6 +43,7 @@
 #define TYPE_NUMBER    "NUMBER"
 #define TYPE_TOPOLOGY  "TOPOLOGY"
 #define TYPE_REPLACE   "REPLACE"
+#define TYPE_CALLOUT   "CALLOUT"
 
 static LIST_HEAD(config_device_list);
 
@@ -78,6 +80,12 @@ static void dump_dev(struct config_device *dev)
                        dev->attr.name, dev->kernel_name,
                        dev->attr.owner, dev->attr.group, dev->attr.mode);
                break;
+       case CALLOUT:
+               dbg("CALLOUT name = '%s', program ='%s', bus = '%s', id = '%s'"
+                       " owner = '%s', group = '%s', mode = '%#o'",
+                       dev->attr.name, dev->exec_program, dev->bus, dev->id,
+                       dev->attr.owner, dev->attr.group, dev->attr.mode);
+               break;
        default:
                dbg("Unknown type of device!");
        }
@@ -330,6 +338,38 @@ static int namedev_init_config(void)
                        strcpy(dev.attr.name, temp3);
                        dbg("REPLACE name = %s, kernel_name = %s", dev.attr.name, dev.kernel_name);
                }
+               if (strcasecmp(temp2, TYPE_CALLOUT) == 0) {
+                       /* number type */
+                       dev.type = CALLOUT;
+
+                       /* PROGRAM="executable" */
+                       retval = get_value("PROGRAM", &temp, &temp3);
+                       if (retval)
+                               continue;
+                       strcpy(dev.exec_program, temp3);
+
+                       /* BUS="bus" */
+                       temp2 = strsep(&temp, ",");
+                       retval = get_value("BUS", &temp, &temp3);
+                       if (retval)
+                               continue;
+                       strcpy(dev.bus, temp3);
+
+                       /* ID="id" */
+                       temp2 = strsep(&temp, ",");
+                       retval = get_value("ID", &temp, &temp3);
+                       if (retval)
+                               continue;
+                       strcpy(dev.id, temp3);
+
+                       /* NAME="new_name" */
+                       temp2 = strsep(&temp, ",");
+                       retval = get_value("NAME", &temp, &temp3);
+                       if (retval)
+                               continue;
+                       strcpy(dev.attr.name, temp3);
+                       dbg("CALLOUT name = %s, program = %s", dev.attr.name, dev.exec_program);
+               }
 
                retval = add_dev(&dev);
                if (retval) {
@@ -417,6 +457,78 @@ static int get_default_mode(struct sysfs_class_device *class_dev)
 }
 
 
+static int exec_callout(struct config_device *dev, char *value, int len)
+{
+       int retval;
+       int res;
+       int status;
+       int fds[2];
+       pid_t pid;
+       int value_set = 0;
+       char buffer[256];
+
+       dbg("callout to %s\n", dev->exec_program);
+       retval = pipe(fds);
+       if (retval != 0) {
+               dbg("pipe failed");
+               return -1;
+       }
+       pid = fork();
+       if (pid == -1) {
+               dbg("fork failed");
+               return -1;
+       }
+
+       if (pid == 0) {
+               /*
+                * child 
+                */
+               close(STDOUT_FILENO);
+               dup(fds[1]);    /* dup write side of pipe to STDOUT */
+               retval = execve(dev->exec_program, main_argv, main_envp);
+               if (retval != 0) {
+                       dbg("child execve failed");
+                       exit(1);
+               }
+               return -1; /* avoid compiler warning */
+       } else {
+               /*
+                * Parent reads from fds[0].
+                */
+               close(fds[1]);
+               retval = 0;
+               while (1) {
+                       res = read(fds[0], buffer, sizeof(buffer) - 1);
+                       if (res <= 0)
+                               break;
+                       buffer[res] = '\0';
+                       if (res > len) {
+                               dbg("callout len %d too short\n", len);
+                               retval = -1;
+                       }
+                       if (value_set) {
+                               dbg("callout value already set");
+                               retval = -1;
+                       } else {
+                               value_set = 1;
+                               strncpy(value, buffer, len);
+                       }
+               }
+               close(fds[0]);
+               res = wait(&status);
+               if (res < 0) {
+                       dbg("wait failed result %d", res);
+                       retval = -1;
+               }
+
+               if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
+                       dbg("callout program status 0x%x", status);
+                       retval = -1;
+               }
+       }
+       return retval;
+}
+
 static int get_attr(struct sysfs_class_device *class_dev, struct device_attr *attr)
 {
        struct list_head *tmp;
@@ -587,6 +699,26 @@ label_found:
                        goto done;
                        break;
                        }
+               case CALLOUT:
+                       {
+                       char value[ID_SIZE];
+
+                       if (exec_callout(dev, value, sizeof(value)))
+                               continue;
+                       if (strncmp(value, dev->id, sizeof(value)) != 0)
+                               continue;
+                       strcpy(attr->name, dev->attr.name);
+                       if (dev->attr.mode != 0) {
+                               attr->mode = dev->attr.mode;
+                               strcpy(attr->owner, dev->attr.owner);
+                               strcpy(attr->group, dev->attr.group);
+                       }
+                       dbg("device callout '%s' becomes '%s' - owner = %s, group = %s, mode = %#o",
+                               dev->id, attr->name, 
+                               dev->attr.owner, dev->attr.group, dev->attr.mode);
+                       goto done;
+                       break;
+                       }
                case REPLACE:
                        if (strcmp(dev->kernel_name, class_dev->name) != 0)
                                continue;

diff --git a/namedev.h b/namedev.h
index d986a2376d36249b96fcb876a28ed7b7ad644f47..1f535c4c8b17e36de73258bf5996d4ec0a74f59e 100644 (file)
--- a/namedev.h
+++ b/namedev.h
@@ -40,6 +40,7 @@ enum config_type {
        NUMBER          = 2,
        TOPOLOGY        = 3,
        REPLACE         = 4,
+       CALLOUT         = 5,
 };
 
 #define BUS_SIZE       30
@@ -60,6 +61,7 @@ struct config_device {
        char id[ID_SIZE];
        char place[PLACE_SIZE];
        char kernel_name[NAME_SIZE];
+       char exec_program[FILE_SIZE];
        
        /* what to set the device to */
        struct device_attr attr;

diff --git a/udev.c b/udev.c
index 6e7ac25175b8dc9450b9426cda9a266f538c2288..0aba8c4bf9aa133999dedb8b8e209d078593aaf3 100644 (file)
--- a/udev.c
+++ b/udev.c
@@ -52,13 +52,19 @@ static char *get_device(void)
        return device;
 }
 
-int main(int argc, char *argv[])
+char **main_argv;
+char **main_envp;
+
+int main(int argc, char **argv, char **envp)
 {
        char *action;
        char *device;
        char *subsystem;
        int retval = -EINVAL;
        
+       main_argv = argv;
+       main_envp = envp;
+
        if (argc != 2) {
                dbg ("unknown number of arguments");
                goto exit;

diff --git a/udev.h b/udev.h
index 590a8ed039dc7411f25c66e4bf9948d1fcfd51c4..e9fc2e46eb86392e211d8f9f6ea986ae34f82ebf 100644 (file)
--- a/udev.h
+++ b/udev.h
@@ -57,5 +57,7 @@ struct device_attr {
 extern int udev_add_device(char *device, char *subsystem);
 extern int udev_remove_device(char *device, char *subsystem);
 
+extern char **main_argv;
+extern char **main_envp;
 #endif