From acf81f97412be44d60be03a0a2e3ca62f4a5146b Mon Sep 17 00:00:00 2001

From: Yu Watanabe <watanabe.yu+github@gmail.com>

Date: Wed, 1 Sep 2021 09:24:15 +0900

Subject: [PATCH] udev-node: split out permission handling from udev_node_add()

And then merge udev_node_add() and udev_node_update_old_links().

(cherry picked from commit 2f48561e0db3cd63f65e9311b4d69282b4ac605d)

Related: #1977994

---

 src/udev/udev-event.c |   9 +-

 src/udev/udev-node.c  | 204 +++++++++++++++++++-----------------------

 src/udev/udev-node.h  |  12 ++-

 3 files changed, 106 insertions(+), 119 deletions(-)

diff --git a/src/udev/udev-event.c b/src/udev/udev-event.c

index b28089be71..8b9f8aecfe 100644

--- a/src/udev/udev-event.c

+++ b/src/udev/udev-event.c

@@ -895,9 +895,6 @@ static int update_devnode(UdevEvent *event) {

         if (r < 0)

                 return log_device_error_errno(dev, r, "Failed to get devnum: %m");

-        /* remove/update possible left-over symlinks from old database entry */

-        (void) udev_node_update_old_links(dev, event->dev_db_clone);

-

         if (!uid_is_valid(event->uid)) {

                 r = device_get_devnode_uid(dev, &event->uid);

                 if (r < 0 && r != -ENOENT)

@@ -921,7 +918,11 @@ static int update_devnode(UdevEvent *event) {

         bool apply_mac = device_for_action(dev, SD_DEVICE_ADD);

-        return udev_node_add(dev, apply_mac, event->mode, event->uid, event->gid, event->seclabel_list);

+        r = udev_node_apply_permissions(dev, apply_mac, event->mode, event->uid, event->gid, event->seclabel_list);

+        if (r < 0)

+                return log_device_error_errno(dev, r, "Failed to apply devnode permissions: %m");

+

+        return udev_node_update(dev, event->dev_db_clone);

 }

 static int event_execute_rules_on_remove(

diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c

index 9e52906571..7cc9ee3670 100644

--- a/src/udev/udev-node.c

+++ b/src/udev/udev-node.c

@@ -356,45 +356,117 @@ static int link_update(sd_device *dev, const char *slink_in, bool add) {

         return i < LINK_UPDATE_MAX_RETRIES ? 0 : -ELOOP;

 }

-int udev_node_update_old_links(sd_device *dev, sd_device *dev_old) {

-        const char *name;

+static int device_get_devpath_by_devnum(sd_device *dev, char **ret) {

+        const char *subsystem;

+        dev_t devnum;

+        int r;

+

+        assert(dev);

+        assert(ret);

+

+        r = sd_device_get_subsystem(dev, &subsystem);

+        if (r < 0)

+                return r;

+

+        r = sd_device_get_devnum(dev, &devnum);

+        if (r < 0)

+                return r;

+

+        return device_path_make_major_minor(streq(subsystem, "block") ? S_IFBLK : S_IFCHR, devnum, ret);

+}

+

+int udev_node_update(sd_device *dev, sd_device *dev_old) {

+        _cleanup_free_ char *filename = NULL;

+        const char *devnode, *devlink;

         int r;

         assert(dev);

         assert(dev_old);

-        /* update possible left-over symlinks */

-        FOREACH_DEVICE_DEVLINK(dev_old, name) {

-                const char *name_current;

-                bool found = false;

+        r = sd_device_get_devname(dev, &devnode);

+        if (r < 0)

+                return log_device_debug_errno(dev, r, "Failed to get devnode: %m");

-                /* check if old link name still belongs to this device */

-                FOREACH_DEVICE_DEVLINK(dev, name_current)

-                        if (streq(name, name_current)) {

-                                found = true;

-                                break;

-                        }

+        if (DEBUG_LOGGING) {

+                const char *id = NULL;

-                if (found)

+                (void) device_get_device_id(dev, &id;;

+                log_device_debug(dev, "Handling device node '%s', devnum=%s", devnode, strna(id));

+        }

+

+        /* update possible left-over symlinks */

+        FOREACH_DEVICE_DEVLINK(dev_old, devlink) {

+                /* check if old link name still belongs to this device */

+                if (device_has_devlink(dev, devlink))

                         continue;

                 log_device_debug(dev,

-                                 "Updating old device symlink '%s', which is no longer belonging to this device.",

-                                 name);

+                                 "Removing/updating old device symlink '%s', which is no longer belonging to this device.",

+                                 devlink);

-                r = link_update(dev, name, false);

+                r = link_update(dev, devlink, /* add = */ false);

                 if (r < 0)

                         log_device_warning_errno(dev, r,

-                                                 "Failed to update device symlink '%s', ignoring: %m",

-                                                 name);

+                                                 "Failed to remove/update device symlink '%s', ignoring: %m",

+                                                 devlink);

         }

+        /* create/update symlinks, add symlinks to name index */

+        FOREACH_DEVICE_DEVLINK(dev, devlink) {

+                r = link_update(dev, devlink, /* add = */ true);

+                if (r < 0)

+                        log_device_warning_errno(dev, r,

+                                                 "Failed to create/update device symlink '%s', ignoring: %m",

+                                                 devlink);

+        }

+

+        r = device_get_devpath_by_devnum(dev, &filename);

+        if (r < 0)

+                return log_device_debug_errno(dev, r, "Failed to get device path: %m");

+

+        /* always add /dev/{block,char}/$major:$minor */

+        r = node_symlink(dev, devnode, filename);

+        if (r < 0)

+                return log_device_warning_errno(dev, r, "Failed to create device symlink '%s': %m", filename);

+

+        return 0;

+}

+

+int udev_node_remove(sd_device *dev) {

+        _cleanup_free_ char *filename = NULL;

+        const char *devlink;

+        int r;

+

+        assert(dev);

+

+        /* remove/update symlinks, remove symlinks from name index */

+        FOREACH_DEVICE_DEVLINK(dev, devlink) {

+                r = link_update(dev, devlink, /* add = */ false);

+                if (r < 0)

+                        log_device_warning_errno(dev, r,

+                                                 "Failed to remove/update device symlink '%s', ignoring: %m",

+                                                 devlink);

+        }

+

+        r = device_get_devpath_by_devnum(dev, &filename);

+        if (r < 0)

+                return log_device_debug_errno(dev, r, "Failed to get device path: %m");

+

+        /* remove /dev/{block,char}/$major:$minor */

+        if (unlink(filename) < 0 && errno != ENOENT)

+                return log_device_debug_errno(dev, errno, "Failed to remove '%s': %m", filename);

+

         return 0;

 }

-static int node_permissions_apply(sd_device *dev, bool apply_mac,

-                                  mode_t mode, uid_t uid, gid_t gid,

-                                  OrderedHashmap *seclabel_list) {

+int udev_node_apply_permissions(

+                sd_device *dev,

+                bool apply_mac,

+                mode_t mode,

+                uid_t uid,

+                gid_t gid,

+                OrderedHashmap *seclabel_list) {

+

         const char *devnode, *subsystem, *id = NULL;

         bool apply_mode, apply_uid, apply_gid;

         _cleanup_close_ int node_fd = -1;

@@ -511,95 +583,5 @@ static int node_permissions_apply(sd_device *dev, bool apply_mac,

         if (r < 0)

                 log_device_debug_errno(dev, r, "Failed to adjust timestamp of node %s: %m", devnode);

-        return r;

-}

-

-static int xsprintf_dev_num_path_from_sd_device(sd_device *dev, char **ret) {

-        const char *subsystem;

-        dev_t devnum;

-        int r;

-

-        assert(ret);

-

-        r = sd_device_get_subsystem(dev, &subsystem);

-        if (r < 0)

-                return r;

-

-        r = sd_device_get_devnum(dev, &devnum);

-        if (r < 0)

-                return r;

-

-        return device_path_make_major_minor(streq(subsystem, "block") ? S_IFBLK : S_IFCHR, devnum, ret);

-}

-

-int udev_node_add(sd_device *dev, bool apply,

-                  mode_t mode, uid_t uid, gid_t gid,

-                  OrderedHashmap *seclabel_list) {

-        const char *devnode, *devlink;

-        _cleanup_free_ char *filename = NULL;

-        int r;

-

-        assert(dev);

-

-        r = sd_device_get_devname(dev, &devnode);

-        if (r < 0)

-                return log_device_debug_errno(dev, r, "Failed to get devnode: %m");

-

-        if (DEBUG_LOGGING) {

-                const char *id = NULL;

-

-                (void) device_get_device_id(dev, &id;;

-                log_device_debug(dev, "Handling device node '%s', devnum=%s", devnode, strna(id));

-        }

-

-        r = node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list);

-        if (r < 0)

-                return r;

-

-        /* create/update symlinks, add symlinks to name index */

-        FOREACH_DEVICE_DEVLINK(dev, devlink) {

-                r = link_update(dev, devlink, true);

-                if (r < 0)

-                        log_device_warning_errno(dev, r,

-                                                 "Failed to update device symlink '%s', ignoring: %m",

-                                                 devlink);

-        }

-

-        r = xsprintf_dev_num_path_from_sd_device(dev, &filename);

-        if (r < 0)

-                return log_device_debug_errno(dev, r, "Failed to get device path: %m");

-

-        /* always add /dev/{block,char}/$major:$minor */

-        r = node_symlink(dev, devnode, filename);

-        if (r < 0)

-                return log_device_warning_errno(dev, r, "Failed to create device symlink '%s': %m", filename);

-

-        return 0;

-}

-

-int udev_node_remove(sd_device *dev) {

-        _cleanup_free_ char *filename = NULL;

-        const char *devlink;

-        int r;

-

-        assert(dev);

-

-        /* remove/update symlinks, remove symlinks from name index */

-        FOREACH_DEVICE_DEVLINK(dev, devlink) {

-                r = link_update(dev, devlink, false);

-                if (r < 0)

-                        log_device_warning_errno(dev, r,

-                                                 "Failed to update device symlink '%s', ignoring: %m",

-                                                 devlink);

-        }

-

-        r = xsprintf_dev_num_path_from_sd_device(dev, &filename);

-        if (r < 0)

-                return log_device_debug_errno(dev, r, "Failed to get device path: %m");

-

-        /* remove /dev/{block,char}/$major:$minor */

-        if (unlink(filename) < 0 && errno != ENOENT)

-                return log_device_debug_errno(dev, errno, "Failed to remove '%s': %m", filename);

-

         return 0;

 }

diff --git a/src/udev/udev-node.h b/src/udev/udev-node.h

index 2349f9c471..a34af77146 100644

--- a/src/udev/udev-node.h

+++ b/src/udev/udev-node.h

@@ -8,10 +8,14 @@

 #include "hashmap.h"

-int udev_node_add(sd_device *dev, bool apply,

-                  mode_t mode, uid_t uid, gid_t gid,

-                  OrderedHashmap *seclabel_list);

+int udev_node_apply_permissions(

+                sd_device *dev,

+                bool apply_mac,

+                mode_t mode,

+                uid_t uid,

+                gid_t gid,

+                OrderedHashmap *seclabel_list);

 int udev_node_remove(sd_device *dev);

-int udev_node_update_old_links(sd_device *dev, sd_device *dev_old);

+int udev_node_update(sd_device *dev, sd_device *dev_old);

 size_t udev_node_escape_path(const char *src, char *dest, size_t size);