#include <errno.h>

#include "sd-device.h"

#include "acl-util.h"

#include "alloc-util.h"

#include "device-util.h"

#include "devnode-acl.h"

#include "dirent-util.h"

#include "escape.h"

#include "fd-util.h"

#include "format-util.h"

#include "set.h"

#include "string-util.h"

#include "util.h"

static int flush_acl(acl_t acl) {

acl_entry_t i;

int found;

bool changed = false;

assert(acl);

for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);

found > 0;

found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {

acl_tag_t tag;

if (acl_get_tag_type(i, &tag) < 0)

return -errno;

if (tag != ACL_USER)

continue;

if (acl_delete_entry(acl, i) < 0)

return -errno;

changed = true;

}

if (found < 0)

return -errno;

return changed;

}

int devnode_acl(const char *path,

bool flush,

bool del, uid_t old_uid,

bool add, uid_t new_uid) {

acl_t acl;

int r = 0;

bool changed = false;

assert(path);

acl = acl_get_file(path, ACL_TYPE_ACCESS);

if (!acl)

return -errno;

if (flush) {

r = flush_acl(acl);

if (r < 0)

goto finish;

if (r > 0)

changed = true;

} else if (del && old_uid > 0) {

acl_entry_t entry;

r = acl_find_uid(acl, old_uid, &entry);

if (r < 0)

goto finish;

if (r > 0) {

if (acl_delete_entry(acl, entry) < 0) {

r = -errno;

goto finish;

}

changed = true;

}

}

if (add && new_uid > 0) {

acl_entry_t entry;

acl_permset_t permset;

int rd, wt;

r = acl_find_uid(acl, new_uid, &entry);

if (r < 0)

goto finish;

if (r == 0) {

if (acl_create_entry(&acl, &entry) < 0) {

r = -errno;

goto finish;

}

if (acl_set_tag_type(entry, ACL_USER) < 0 ||

acl_set_qualifier(entry, &new_uid) < 0) {

r = -errno;

goto finish;

}

}

if (acl_get_permset(entry, &permset) < 0) {

r = -errno;

goto finish;

}

rd = acl_get_perm(permset, ACL_READ);

if (rd < 0) {

r = -errno;

goto finish;

}

wt = acl_get_perm(permset, ACL_WRITE);

if (wt < 0) {

r = -errno;

goto finish;

}

if (!rd || !wt) {

if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0) {

r = -errno;

goto finish;

}

changed = true;

}

}

if (!changed)

goto finish;

if (acl_calc_mask(&acl) < 0) {

r = -errno;

goto finish;

}

if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0) {

r = -errno;

goto finish;

}

r = 0;

finish:

acl_free(acl);

return r;

}

int devnode_acl_all(const char *seat,

bool flush,

bool del, uid_t old_uid,

bool add, uid_t new_uid) {

_cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;

_cleanup_set_free_free_ Set *nodes = NULL;

_cleanup_closedir_ DIR *dir = NULL;

struct dirent *dent;

sd_device *d;

char *n;

int r;

nodes = set_new(&path_hash_ops);

if (!nodes)

return -ENOMEM;

r = sd_device_enumerator_new(&e);

if (r < 0)

return r;

if (isempty(seat))

seat = "seat0";

/* We can only match by one tag in libudev. We choose

r = sd_device_enumerator_add_match_tag(e, "uaccess");

if (r < 0)

return r;

FOREACH_DEVICE(e, d) {

const char *node, *sn;

/* Make sure the tag is still in place */

if (sd_device_has_current_tag(d, "uaccess") <= 0)

continue;

if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))

sn = "seat0";

if (!streq(seat, sn))

continue;

/* In case people mistag devices with nodes, we need to ignore this */

if (sd_device_get_devname(d, &node) < 0)

continue;

log_device_debug(d, "Found udev node %s for seat %s", node, seat);

r = set_put_strdup(&nodes, node);

if (r < 0)

return r;

}

/* udev exports "dead" device nodes to allow module on-demand loading,

dir = opendir("/run/udev/static_node-tags/uaccess");

if (dir) {

FOREACH_DIRENT(dent, dir, return -errno) {

_cleanup_free_ char *unescaped_devname = NULL;

if (cunescape(dent->d_name, UNESCAPE_RELAX, &unescaped_devname) < 0)

return -ENOMEM;

n = path_join("/dev", unescaped_devname);

if (!n)

return -ENOMEM;

log_debug("Found static node %s for seat %s", n, seat);

r = set_consume(nodes, n);

if (r == -EEXIST)

continue;

if (r < 0)

return r;

}

}

r = 0;

SET_FOREACH(n, nodes) {

int k;

log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"→"UID_FMT"%s%s)",

n, seat, old_uid, new_uid,

del ? " del" : "", add ? " add" : "");

k = devnode_acl(n, flush, del, old_uid, add, new_uid);

if (k == -ENOENT)

log_debug("Device %s disappeared while setting ACLs", n);

else if (k < 0 && r == 0)

r = k;

}

return r;

}