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am d57125af: Merge "Give secondary users read-only physical cards." into mnc-dev

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* commit 'd57125af1a81f34b162ecd5de81e6f1365aff588':
  Give secondary users read-only physical cards.
This commit is contained in:
Jeff Sharkey 2015-07-29 01:34:37 +00:00 committed by Android Git Automerger
commit d3a5e857e4
1 changed files with 46 additions and 25 deletions
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71
sdcard/sdcard.c
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@ -151,7 +151,7 @@ struct node {
perm_t perm;
userid_t userid;
uid_t uid;
mode_t mode;
bool under_android;
struct node *next; /* per-dir sibling list */
struct node *child; /* first contained file by this dir */
@ -419,11 +419,20 @@ static void attr_from_stat(struct fuse* fuse, struct fuse_attr *attr,
attr->gid = multiuser_get_uid(node->userid, fuse->gid);
}
/* Filter requested mode based on underlying file, and
* pass through file type. */
int visible_mode = node->mode;
if (node->perm != PERM_PRE_ROOT) {
visible_mode = visible_mode & ~fuse->mask;
int visible_mode = 0775 & ~fuse->mask;
if (node->perm == PERM_PRE_ROOT) {
/* Top of multi-user view should always be visible to ensure
* secondary users can traverse inside. */
visible_mode = 0711;
} else if (node->under_android) {
/* Block "other" access to Android directories, since only apps
* belonging to a specific user should be in there; we still
* leave +x open for the default view. */
if (fuse->gid == AID_SDCARD_RW) {
visible_mode = visible_mode & ~0006;
} else {
visible_mode = visible_mode & ~0007;
}
}
int owner_mode = s->st_mode & 0700;
int filtered_mode = visible_mode & (owner_mode | (owner_mode >> 3) | (owner_mode >> 6));
@ -452,7 +461,7 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
node->perm = PERM_INHERIT;
node->userid = parent->userid;
node->uid = parent->uid;
node->mode = parent->mode;
node->under_android = parent->under_android;
/* Derive custom permissions based on parent and current node */
switch (parent->perm) {
@ -463,33 +472,28 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
/* Legacy internal layout places users at top level */
node->perm = PERM_ROOT;
node->userid = strtoul(node->name, NULL, 10);
node->mode = 0771;
break;
case PERM_ROOT:
/* Assume masked off by default. */
node->mode = 0770;
if (!strcasecmp(node->name, "Android")) {
/* App-specific directories inside; let anyone traverse */
node->perm = PERM_ANDROID;
node->mode = 0771;
node->under_android = true;
}
break;
case PERM_ANDROID:
if (!strcasecmp(node->name, "data")) {
/* App-specific directories inside; let anyone traverse */
node->perm = PERM_ANDROID_DATA;
node->mode = 0771;
} else if (!strcasecmp(node->name, "obb")) {
/* App-specific directories inside; let anyone traverse */
node->perm = PERM_ANDROID_OBB;
node->mode = 0771;
/* Single OBB directory is always shared */
node->graft_path = fuse->global->obb_path;
node->graft_pathlen = strlen(fuse->global->obb_path);
} else if (!strcasecmp(node->name, "media")) {
/* App-specific directories inside; let anyone traverse */
node->perm = PERM_ANDROID_MEDIA;
node->mode = 0771;
}
break;
case PERM_ANDROID_DATA:
@ -499,7 +503,6 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
if (appid != 0) {
node->uid = multiuser_get_uid(parent->userid, appid);
}
node->mode = 0770;
break;
}
}
@ -1730,6 +1733,7 @@ static int usage() {
ERROR("usage: sdcard [OPTIONS] <source_path> <label>\n"
" -u: specify UID to run as\n"
" -g: specify GID to run as\n"
" -U: specify user ID that owns device\n"
" -m: source_path is multi-user\n"
" -w: runtime_write mount has full write access\n"
"\n");
@ -1763,7 +1767,7 @@ static int fuse_setup(struct fuse* fuse, gid_t gid, mode_t mask) {
}
static void run(const char* source_path, const char* label, uid_t uid,
gid_t gid, bool multi_user, bool full_write) {
gid_t gid, userid_t userid, bool multi_user, bool full_write) {
struct fuse_global global;
struct fuse fuse_default;
struct fuse fuse_read;
@ -1796,18 +1800,17 @@ static void run(const char* source_path, const char* label, uid_t uid,
global.root.refcount = 2;
global.root.namelen = strlen(source_path);
global.root.name = strdup(source_path);
global.root.userid = 0;
global.root.userid = userid;
global.root.uid = AID_ROOT;
global.root.under_android = false;
strcpy(global.source_path, source_path);
if (multi_user) {
global.root.perm = PERM_PRE_ROOT;
global.root.mode = 0711;
snprintf(global.obb_path, sizeof(global.obb_path), "%s/obb", source_path);
} else {
global.root.perm = PERM_ROOT;
global.root.mode = 0771;
snprintf(global.obb_path, sizeof(global.obb_path), "%s/Android/obb", source_path);
}
@ -1833,11 +1836,25 @@ static void run(const char* source_path, const char* label, uid_t uid,
umask(0);
if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
|| fuse_setup(&fuse_read, AID_EVERYBODY, 0027)
|| fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0027)) {
ERROR("failed to fuse_setup\n");
exit(1);
if (multi_user) {
/* Multi-user storage is fully isolated per user, so "other"
* permissions are completely masked off. */
if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
|| fuse_setup(&fuse_read, AID_EVERYBODY, 0027)
|| fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0027)) {
ERROR("failed to fuse_setup\n");
exit(1);
}
} else {
/* Physical storage is readable by all users on device, but
* the Android directories are masked off to a single user
* deep inside attr_from_stat(). */
if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
|| fuse_setup(&fuse_read, AID_EVERYBODY, full_write ? 0027 : 0022)
|| fuse_setup(&fuse_write, AID_EVERYBODY, full_write ? 0007 : 0022)) {
ERROR("failed to fuse_setup\n");
exit(1);
}
}
/* Drop privs */
@ -1875,6 +1892,7 @@ int main(int argc, char **argv) {
const char *label = NULL;
uid_t uid = 0;
gid_t gid = 0;
userid_t userid = 0;
bool multi_user = false;
bool full_write = false;
int i;
@ -1882,7 +1900,7 @@ int main(int argc, char **argv) {
int fs_version;
int opt;
while ((opt = getopt(argc, argv, "u:g:mw")) != -1) {
while ((opt = getopt(argc, argv, "u:g:U:mw")) != -1) {
switch (opt) {
case 'u':
uid = strtoul(optarg, NULL, 10);
@ -1890,6 +1908,9 @@ int main(int argc, char **argv) {
case 'g':
gid = strtoul(optarg, NULL, 10);
break;
case 'U':
userid = strtoul(optarg, NULL, 10);
break;
case 'm':
multi_user = true;
break;
@ -1938,6 +1959,6 @@ int main(int argc, char **argv) {
sleep(1);
}
run(source_path, label, uid, gid, multi_user, full_write);
run(source_path, label, uid, gid, userid, multi_user, full_write);
return 1;
}