X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev.c;h=67b86e5916ced757a921bbbd442bee3e876c6298;hp=971ac10809bedb81be6584cc64a16da5e6b91719;hb=5aebfbcb62614fc2bf2b1579d62e3fe272c6751a;hpb=85511f02466297b7dca07c3fe5491230f3f06d14 diff --git a/udev.c b/udev.c index 971ac1080..67b86e591 100644 --- a/udev.c +++ b/udev.c @@ -27,12 +27,19 @@ #include #include #include +#include #include "udev.h" #include "udev_version.h" +#include "namedev.h" +#include "udevdb.h" +#include "libsysfs/libsysfs.h" +/* global variables */ +char **main_argv; +char **main_envp; -static char *get_action(void) +static inline char *get_action(void) { char *action; @@ -40,231 +47,156 @@ static char *get_action(void) return action; } - -static char *get_device(void) +static inline char *get_devpath(void) { - static char device[255]; - char *temp; - - temp = getenv("DEVPATH"); - if (temp == NULL) - return NULL; - strcpy(device, SYSFS_ROOT); - strcat(device, temp); + char *devpath; - return device; + devpath = getenv("DEVPATH"); + return devpath; } -/* - * Right now the major/minor of a device is stored in a file called - * "dev" in sysfs. - * The number is stored as: - * MMmm - * MM is the major - * mm is the minor - * The value is in hex. - * Yes, this will probably change when we go to a bigger major/minor - * range, and will have to be changed at that time. - */ -static int get_major_minor (char *dev, int *major, int *minor) +static inline char *get_seqnum(void) { - char filename[255]; - char line[20]; - char temp[3]; - int fd; - int retval = 0; - - /* add the dev file to the directory and see if it's present */ - strncpy(filename, dev, sizeof(filename)); - strncat(filename, DEV_FILE, sizeof(filename)); - fd = open(filename, O_RDONLY); - if (fd < 0) { - dbg("Can't open %s", filename); - return -ENODEV; - } - - /* get the major/minor */ - retval = read(fd, line, sizeof(line)); - if (retval < 0) { - dbg("read error on %s", dev); - goto exit; - } + char *seqnum; - temp[0] = line[0]; - temp[1] = line[1]; - temp[2] = 0x00; - *major = (int)strtol(&temp[0], NULL, 16); - - temp[0] = line[2]; - temp[1] = line[3]; - temp[2] = 0x00; - *minor = (int)strtol(&temp[0], NULL, 16); - - dbg("found major = %d, minor = %d", *major, *minor); - - retval = 0; -exit: - close(fd); - return retval; + seqnum = getenv("SEQNUM"); + return seqnum; } -/* - * Here would go a call to the naming deamon, to get the name we want to have - * for this device. But for now, let's just default to whatever the kernel is - * calling the device as that will keep the "old-style" naming policy - */ -static char *get_name(char *dev, int major, int minor) -{ - static char name[100]; - char *temp; +#ifdef USE_DBUS - temp = strrchr(dev, '/'); - if (temp == NULL) - return NULL; - strncpy(name, &temp[1], sizeof(name)); - - dbg("name is %s", name); - - return &name[0]; -} - -/* - * Again, this will live in the naming deamon +/** Global variable for the connection the to system message bus or #NULL + * if we cannot connect or acquire the org.kernel.udev service */ -static int get_mode(char *name, char *dev, int major, int minor) -{ - /* just default everyone to rw for the world! */ - return 0666; -} +DBusConnection* sysbus_connection; -/* - * We also want to add some permissions here, and possibly some symlinks - */ -static int create_node(char *name, char type, int major, int minor, int mode) +/** Disconnect from the system message bus */ +static void sysbus_disconnect() { - char *argv[7]; - char mode_string[100]; - char type_string[3]; - char major_string[20]; - char minor_string[20]; - char filename[255]; - int retval = 0; - - strncpy(filename, UDEV_ROOT, sizeof(filename)); - strncat(filename, name, sizeof(filename)); - - snprintf(mode_string, sizeof(mode_string), "--mode=%#o", mode); - snprintf(type_string, sizeof(type_string), "%c", type); - snprintf(major_string, sizeof(major_string), "%d", major); - snprintf(minor_string, sizeof(minor_string), "%d", minor); - - argv[0] = MKNOD; - argv[1] = mode_string; - argv[2] = filename; - argv[3] = type_string; - argv[4] = major_string; - argv[5] = minor_string; - argv[6] = NULL; - dbg ("executing %s %s %s %s %s %s", - argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]); - switch (fork()) { - case 0: - /* we are the child, so lets run the program */ - execv (MKNOD, argv); - exit(0); - break; - case (-1): - dbg ("fork failed."); - retval = -EFAULT; - break; - default: - break; - } - return retval; -} + if (sysbus_connection == NULL) + return; -static int remove_node(char *name) -{ - return 0; + dbus_connection_disconnect(sysbus_connection); + sysbus_connection = NULL; } -static int do_it(char *action, char *name, char type, int major, int minor, int mode) +/** Connect to the system message bus */ +static void sysbus_connect() { - if (strcmp(action, "add") == 0) - return create_node(name, type, major, minor, mode); - - if (strcmp(action, "remove") == 0) - return remove_node(name); - - dbg("Unknown action: %s", action); - return -EINVAL; + DBusError error; + + /* Connect to a well-known bus instance, the system bus */ + dbus_error_init(&error); + sysbus_connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error); + if (sysbus_connection == NULL) { + dbg("cannot connect to system message bus, error %s: %s", + error.name, error.message); + dbus_error_free(&error); + return; + } + + /* Acquire the org.kernel.udev service such that listeners + * know that the message is really from us and not from a + * random attacker. See the file udev_sysbus_policy.conf for + * details. + * + * Note that a service can have multiple owners (though there + * is a concept of a primary owner for reception of messages) + * so no race is introduced if two copies of udev is running + * at the same time. + */ + dbus_bus_acquire_service(sysbus_connection, "org.kernel.udev", 0, + &error); + if (dbus_error_is_set(&error)) { + printf("cannot acquire org.kernel.udev service, error %s: %s'", + error.name, error.message); + sysbus_disconnect(); + return; + } } -int main(int argc, char *argv[]) +#endif /* USE_DBUS */ + +int main(int argc, char **argv, char **envp) { - char *subsystem; char *action; - char *device; - char *name; - char type; - int major; - int minor; - int mode; + char *devpath; + char *subsystem; int retval = -EINVAL; + main_argv = argv; + main_envp = envp; + + dbg("version %s", UDEV_VERSION); + if (argc != 2) { dbg ("unknown number of arguments"); goto exit; } - /* for now, the block layer is the only place where block devices are */ subsystem = argv[1]; - if (strcmp(subsystem, "block") == 0) - type = 'b'; - else - type = 'c'; - action = get_action(); - if (!action) { - dbg ("no action?"); + devpath = get_devpath(); + if (!devpath) { + dbg ("no devpath?"); goto exit; } + dbg("looking at '%s'", devpath); - device = get_device(); - if (!device) { - dbg ("no device?"); + /* we only care about class devices and block stuff */ + if (!strstr(devpath, "class") && + !strstr(devpath, "block")) { + dbg("not a block or class device"); goto exit; } - dbg("looking at %s", device); - retval = get_major_minor(device, &major, &minor); - if (retval) { - dbg ("get_major_minor failed"); + /* but we don't care about net class devices */ + if (strcmp(subsystem, "net") == 0) { + dbg("don't care about net devices"); goto exit; } - name = get_name(device, major, minor); - if (name == NULL) { - dbg ("get_name failed"); - retval = -ENODEV; + action = get_action(); + if (!action) { + dbg ("no action?"); goto exit; } - mode = get_mode(name, device, major, minor); - if (mode < 0) { - dbg ("get_mode failed"); - retval = -EINVAL; + /* initialize our configuration */ + udev_init_config(); + +#ifdef USE_DBUS + /* connect to the system message bus */ + sysbus_connect(); +#endif /* USE_DBUS */ + + /* initialize udev database */ + retval = udevdb_init(UDEVDB_DEFAULT); + if (retval != 0) { + dbg("unable to initialize database"); goto exit; } - retval = do_it(action, name, type, major, minor, mode); - if (retval) { - dbg ("do_it failed"); - goto exit; + /* initialize the naming deamon */ + namedev_init(); + + if (strcmp(action, "add") == 0) + retval = udev_add_device(devpath, subsystem); + + else if (strcmp(action, "remove") == 0) + retval = udev_remove_device(devpath, subsystem); + + else { + dbg("unknown action '%s'", action); + retval = -EINVAL; } + udevdb_exit(); + +#ifdef USE_DBUS + /* disconnect from the system message bus */ + sysbus_disconnect(); +#endif /* USE_DBUS */ - retval = 0; exit: return retval; } -