refactor libnss.zig

src/DB.zig

@@ -280,7 +280,7 @@ pub fn fromBytes(buf: []align(8) const u8) InvalidHeader!DB {
 }
 
 // dumps PackedGroup to []u8 and returns a CGroup.
-fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{BufferTooSmall}!CGroup {
+pub fn getGroup(self: *const DB, group: PackedGroup, buf: []u8) error{BufferTooSmall}!CGroup {
     const members_slice = self.groupmembers[group.members_offset..];
     var vit = compress.VarintSliceIteratorMust(members_slice);
     const num_members = vit.remaining;

src/libnss.zig

@@ -108,20 +108,21 @@ export fn _nss_turbo_getpwuid_r(
     buflen: usize,
     errnop: *c_int,
 ) c.enum_nss_status {
-    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    const db = getDBErrno(errnop) orelse return c.NSS_STATUS_UNAVAIL;
-    if (db.getpwuid(uid, buffer[0..buflen])) |maybe_cuser| {
+
-        if (maybe_cuser) |cuser| {
+    var cuser = db.getpwuid(uid, buffer[0..buflen]) catch |err| switch (err) {
-            passwd.* = cuser;
-            return c.NSS_STATUS_SUCCESS;
-        } else {
-            errnop.* = @enumToInt(os.E.NOENT);
-            return c.NSS_STATUS_NOTFOUND;
-        }
-    } else |err| switch (err) {
         error.BufferTooSmall => {
             errnop.* = @enumToInt(os.E.RANGE);
             return c.NSS_STATUS_TRYAGAIN;
         },
+    };
+
+    if (cuser) |got| {
+        passwd.* = got;
+        return c.NSS_STATUS_SUCCESS;
+    } else {
+        errnop.* = @enumToInt(os.E.NOENT);
+        return c.NSS_STATUS_NOTFOUND;
     }
 }
 
@@ -132,21 +133,23 @@ export fn _nss_turbo_getpwnam_r(
     buflen: usize,
     errnop: *c_int,
 ) c.enum_nss_status {
-    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    const db = getDBErrno(errnop) orelse return c.NSS_STATUS_UNAVAIL;
     const nameSlice = mem.sliceTo(name, 0);
-    if (db.getpwnam(nameSlice, buffer[0..buflen])) |maybe_cuser| {
+
-        if (maybe_cuser) |cuser| {
+    var buf = buffer[0..buflen];
-            passwd.* = cuser;
+    const cuser = db.getpwnam(nameSlice, buf) catch |err| switch (err) {
-            return c.NSS_STATUS_SUCCESS;
-        } else {
-            errnop.* = @enumToInt(os.E.NOENT);
-            return c.NSS_STATUS_NOTFOUND;
-        }
-    } else |err| switch (err) {
         error.BufferTooSmall => {
             errnop.* = @enumToInt(os.E.RANGE);
             return c.NSS_STATUS_TRYAGAIN;
         },
+    };
+
+    if (cuser) |got| {
+        passwd.* = got;
+        return c.NSS_STATUS_SUCCESS;
+    } else {
+        errnop.* = @enumToInt(os.E.NOENT);
+        return c.NSS_STATUS_NOTFOUND;
     }
 }
 
@@ -157,20 +160,20 @@ export fn _nss_turbo_getgrgid_r(
     buflen: usize,
     errnop: *c_int,
 ) c.enum_nss_status {
-    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    const db = getDBErrno(errnop) orelse return c.NSS_STATUS_UNAVAIL;
-    if (db.getgrgid(gid, buffer[0..buflen])) |maybe_cgroup| {
+    var cgroup = db.getgrgid(gid, buffer[0..buflen]) catch |err| switch (err) {
-        if (maybe_cgroup) |cgroup| {
-            gr.* = cgroup;
-            return c.NSS_STATUS_SUCCESS;
-        } else {
-            errnop.* = @enumToInt(os.E.NOENT);
-            return c.NSS_STATUS_NOTFOUND;
-        }
-    } else |err| switch (err) {
         error.BufferTooSmall => {
             errnop.* = @enumToInt(os.E.RANGE);
             return c.NSS_STATUS_TRYAGAIN;
         },
+    };
+
+    if (cgroup) |got| {
+        gr.* = got;
+        return c.NSS_STATUS_SUCCESS;
+    } else {
+        errnop.* = @enumToInt(os.E.NOENT);
+        return c.NSS_STATUS_NOTFOUND;
     }
 }
 
@@ -181,27 +184,29 @@ export fn _nss_turbo_getgrnam_r(
     buflen: usize,
     errnop: *c_int,
 ) c.enum_nss_status {
-    const db = getDb(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+    const db = getDBErrno(errnop) orelse return c.NSS_STATUS_UNAVAIL;
     const nameSlice = mem.sliceTo(name, 0);
-    if (db.getgrnam(nameSlice, buffer[0..buflen])) |maybe_cgroup| {
+    var buf = buffer[0..buflen];
-        if (maybe_cgroup) |cgroup| {
+    var cgroup = db.getgrnam(nameSlice, buf) catch |err| switch (err) {
-            group.* = cgroup;
+        error.BufferTooSmall => {
+            errnop.* = @enumToInt(os.E.RANGE);
+            return c.NSS_STATUS_TRYAGAIN;
+        },
+    };
+
+    if (cgroup) |got| {
+        group.* = got;
         return c.NSS_STATUS_SUCCESS;
     } else {
         errnop.* = @enumToInt(os.E.NOENT);
         return c.NSS_STATUS_NOTFOUND;
     }
-    } else |err| switch (err) {
-        error.BufferTooSmall => {
-            errnop.* = @enumToInt(os.E.RANGE);
-            return c.NSS_STATUS_TRYAGAIN;
-        },
-    }
 }
 
 export fn _nss_turbo_setpwent(_: c_int) void {
     global_init.call();
-    if (global_state) |*state| {
+    var state = global_state orelse return;
+
     state.getpwent_iterator_mu.lock();
     defer state.getpwent_iterator_mu.unlock();
 
@@ -213,7 +218,6 @@ export fn _nss_turbo_setpwent(_: c_int) void {
         },
     );
 }
-}
 
 export fn _nss_turbo_endpwent() void {
     global_init.call();
@@ -225,36 +229,75 @@ export fn _nss_turbo_endpwent() void {
 }
 
 export fn _nss_turbo_setgrent(_: c_int) void {
-    global_init.call();
+    var state = getState() orelse return;
-    if (global_state) |*state| {
     state.getgrent_iterator_mu.lock();
     defer state.getgrent_iterator_mu.unlock();
-
     state.getgrent_iterator = PackedGroup.iterator(
         state.file.db.groups,
     );
 }
-}
 
 export fn _nss_turbo_endgrent() void {
-    global_init.call();
+    var state = getState() orelse return;
-    if (global_state) |*state| {
     state.getgrent_iterator_mu.lock();
     defer state.getgrent_iterator_mu.unlock();
     state.getgrent_iterator = null;
 }
+
+export fn _nss_turbo_getgrent_r(
+    result: *CGroup,
+    buffer: [*]u8,
+    buflen: usize,
+    errnop: *c_int,
+) c.enum_nss_status {
+    var state = getStateErrno(errnop) orelse return c.NSS_STATUS_UNAVAIL;
+
+    state.getgrent_iterator_mu.lock();
+    defer state.getgrent_iterator_mu.unlock();
+
+    var it = state.getgrent_iterator orelse {
+        // logic from _nss_systemd_getgrent_r
+        errnop.* = @enumToInt(os.E.HOSTDOWN);
+        return c.NSS_STATUS_UNAVAIL;
+    };
+
+    var group = it.next() orelse {
+        errnop.* = @enumToInt(os.E.NOENT);
+        return c.NSS_STATUS_NOTFOUND;
+    };
+
+    if (state.file.db.getGroup(group, buffer[0..buflen])) |cgroup| {
+        result.* = cgroup;
+        return c.NSS_STATUS_SUCCESS;
+    } else |err| switch (err) {
+        error.BufferTooSmall => {
+            errnop.* = @enumToInt(os.E.RANGE);
+            return c.NSS_STATUS_TRYAGAIN;
+        },
+    }
 }
 
-fn getDb(errnop: *c_int) ?DB {
+fn getState() ?State {
+    global_init.call();
+    return global_state;
+}
+
+fn getStateErrno(errnop: *c_int) ?State {
     global_init.call();
     if (global_state) |state| {
-        return state.file.db;
+        return state;
     } else {
         errnop.* = @enumToInt(os.E.AGAIN);
         return null;
     }
 }
 
+fn getDBErrno(errnop: *c_int) ?DB {
+    if (getStateErrno(errnop)) |state| {
+        return state.file.db;
+    } else return null;
+}
+
 const testing = std.testing;
 
 test "getpwuid_r and getpwnam_r" {