Auto merge of #3228 - redox-os:redox-pw, r=JohnTitor

redox: add grp.h and pwd.h functions for the users crate

libc-test/semver/redox.txt

@@ -137,8 +137,8 @@ SO_PEERCRED
 SO_PEERSEC
 SO_PRIORITY
 SO_PROTOCOL
-SO_REUSEPORT
 SO_RCVBUFFORCE
+SO_REUSEPORT
 SO_SNDBUFFORCE
 TCFLSH
 TCGETS
@@ -180,6 +180,7 @@ bsearch
 chroot
 clearerr
 difftime
+endpwent
 endservent
 epoll_create
 epoll_create1
@@ -189,12 +190,17 @@ epoll_wait
 explicit_bzero
 fchdir
 fmemopen
+getdtablesize
+getgrgid_r
+getgrnam_r
+getgrouplist
 getline
+getpwent
+getpwnam_r
 getrlimit
 getrusage
 getservbyport
 getservent
-getdtablesize
 killpg
 lockf
 madvise
@@ -206,6 +212,7 @@ pipe2
 pthread_condattr_setclock
 qsort
 reallocarray
+setpwent
 setrlimit
 setservent
 strcasecmp

src/unix/redox/mod.rs

@@ -996,6 +996,28 @@ extern "C" {
     pub fn pipe2(fds: *mut ::c_int, flags: ::c_int) -> ::c_int;
     pub fn getdtablesize() -> ::c_int;
 
+    // grp.h
+    pub fn getgrgid_r(
+        gid: ::gid_t,
+        grp: *mut ::group,
+        buf: *mut ::c_char,
+        buflen: ::size_t,
+        result: *mut *mut ::group,
+    ) -> ::c_int;
+    pub fn getgrnam_r(
+        name: *const ::c_char,
+        grp: *mut ::group,
+        buf: *mut ::c_char,
+        buflen: ::size_t,
+        result: *mut *mut ::group,
+    ) -> ::c_int;
+    pub fn getgrouplist(
+        user: *const ::c_char,
+        group: ::gid_t,
+        groups: *mut ::gid_t,
+        ngroups: *mut ::c_int,
+    ) -> ::c_int;
+
     // malloc.h
     pub fn memalign(align: ::size_t, size: ::size_t) -> *mut ::c_void;
 
@@ -1028,6 +1050,16 @@ extern "C" {
     ) -> ::c_int;
 
     // pwd.h
+    pub fn getpwent() -> *mut passwd;
+    pub fn setpwent();
+    pub fn endpwent();
+    pub fn getpwnam_r(
+        name: *const ::c_char,
+        pwd: *mut passwd,
+        buf: *mut ::c_char,
+        buflen: ::size_t,
+        result: *mut *mut passwd,
+    ) -> ::c_int;
     pub fn getpwuid_r(
         uid: ::uid_t,
         pwd: *mut passwd,