bionic: Implement getpwent and getgrent
Not efficient to iterate through given the large number of Android
ids (AID). Compile warning will result if you use these functions,
telling you as much. Not for general consumption, however for
example, some filesystem tests would like to see these to perform
all corners.
About 1/4 second for getpwent, and 1/8 second for getgrent to iterate
through all reserved Android aids.
Bug: 27999086
Change-Id: I7784273b7875c38e4954ae21d314f35e4bf8c2fc
diff --git a/libc/bionic/grp_pwd.cpp b/libc/bionic/grp_pwd.cpp
index d75b94d..332b2b8 100644
--- a/libc/bionic/grp_pwd.cpp
+++ b/libc/bionic/grp_pwd.cpp
@@ -54,6 +54,8 @@
group group_;
char* group_members_[2];
char group_name_buffer_[32];
+ // Must be last so init_group_state can run a simple memset for the above
+ ssize_t getgrent_idx;
};
struct passwd_state_t {
@@ -61,13 +63,14 @@
char name_buffer_[32];
char dir_buffer_[32];
char sh_buffer_[32];
+ ssize_t getpwent_idx;
};
static ThreadLocalBuffer<group_state_t> g_group_tls_buffer;
static ThreadLocalBuffer<passwd_state_t> g_passwd_tls_buffer;
static void init_group_state(group_state_t* state) {
- memset(state, 0, sizeof(group_state_t));
+ memset(state, 0, sizeof(group_state_t) - sizeof(state->getgrent_idx));
state->group_.gr_mem = state->group_members_;
}
@@ -467,6 +470,60 @@
return (pw != NULL) ? pw->pw_name : NULL;
}
+void setpwent() {
+ passwd_state_t* state = g_passwd_tls_buffer.get();
+ if (state) {
+ state->getpwent_idx = 0;
+ }
+}
+
+void endpwent() {
+ setpwent();
+}
+
+passwd* getpwent() {
+ passwd_state_t* state = g_passwd_tls_buffer.get();
+ if (state == NULL) {
+ return NULL;
+ }
+ if (state->getpwent_idx < 0) {
+ return NULL;
+ }
+
+ size_t start = 0;
+ ssize_t end = android_id_count;
+ if (state->getpwent_idx < end) {
+ return android_iinfo_to_passwd(state, android_ids + state->getpwent_idx++);
+ }
+
+ start = end;
+ end += AID_OEM_RESERVED_END - AID_OEM_RESERVED_START + 1;
+
+ if (state->getpwent_idx < end) {
+ return oem_id_to_passwd(
+ state->getpwent_idx++ - start + AID_OEM_RESERVED_START, state);
+ }
+
+ start = end;
+ end += AID_OEM_RESERVED_2_END - AID_OEM_RESERVED_2_START + 1;
+
+ if (state->getpwent_idx < end) {
+ return oem_id_to_passwd(
+ state->getpwent_idx++ - start + AID_OEM_RESERVED_2_START, state);
+ }
+
+ start = end;
+ end += AID_USER - AID_APP; // Do not expose higher users
+
+ if (state->getpwent_idx < end) {
+ return app_id_to_passwd(state->getpwent_idx++ - start + AID_APP, state);
+ }
+
+ // We are not reporting u1_a* and higher or we will be here forever
+ state->getpwent_idx = -1;
+ return NULL;
+}
+
static group* getgrgid_internal(gid_t gid, group_state_t* state) {
group* grp = android_id_to_group(state, gid);
if (grp != NULL) {
@@ -537,3 +594,61 @@
struct group **result) {
return getgroup_r(true, name, 0, grp, buf, buflen, result);
}
+
+void setgrent() {
+ group_state_t* state = g_group_tls_buffer.get();
+ if (state) {
+ state->getgrent_idx = 0;
+ }
+}
+
+void endgrent() {
+ setgrent();
+}
+
+group* getgrent() {
+ group_state_t* state = g_group_tls_buffer.get();
+ if (state == NULL) {
+ return NULL;
+ }
+ if (state->getgrent_idx < 0) {
+ return NULL;
+ }
+
+ size_t start = 0;
+ ssize_t end = android_id_count;
+ if (state->getgrent_idx < end) {
+ init_group_state(state);
+ return android_iinfo_to_group(state, android_ids + state->getgrent_idx++);
+ }
+
+ start = end;
+ end += AID_OEM_RESERVED_END - AID_OEM_RESERVED_START + 1;
+
+ if (state->getgrent_idx < end) {
+ init_group_state(state);
+ return oem_id_to_group(
+ state->getgrent_idx++ - start + AID_OEM_RESERVED_START, state);
+ }
+
+ start = end;
+ end += AID_OEM_RESERVED_2_END - AID_OEM_RESERVED_2_START + 1;
+
+ if (state->getgrent_idx < end) {
+ init_group_state(state);
+ return oem_id_to_group(
+ state->getgrent_idx++ - start + AID_OEM_RESERVED_2_START, state);
+ }
+
+ start = end;
+ end += AID_USER - AID_APP; // Do not expose higher groups
+
+ if (state->getgrent_idx < end) {
+ init_group_state(state);
+ return app_id_to_group(state->getgrent_idx++ - start + AID_APP, state);
+ }
+
+ // We are not reporting u1_a* and higher or we will be here forever
+ state->getgrent_idx = -1;
+ return NULL;
+}