apps/su.cpp

@@ -1,12 +1,11 @@
 #include <os/ArgumentParser.h>
-#include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 int main(int argc, char** argv)
 {
-    StringView name;
+    StringView id;
 
     if (geteuid() != 0)
     {
@@ -15,24 +14,19 @@ int main(int argc, char** argv)
     }
 
     os::ArgumentParser parser;
-    parser.add_positional_argument(name, "name"_sv, true);
+    parser.add_positional_argument(id, "id"_sv, true);
     parser.parse(argc, argv);
 
-    struct passwd* entry = getpwnam(name.chars());
+    int uid = atoi(id.chars());
-    if (!entry)
+
+    if (uid == 0)
     {
-        fprintf(stderr, "su: user %s not found!\n", name.chars());
+        fprintf(stderr, "Already root!\n");
         return 1;
     }
 
-    if (getuid() != geteuid())
+    setgid(uid);
-    {
+    setuid(uid);
-        fprintf(stderr, "FIXME: you have to enter %s's password first!\n", name.chars());
-        return 1;
-    }
 
-    setgid(entry->pw_gid);
+    execl("/bin/sh", "sh", NULL);
-    setuid(entry->pw_uid);
-
-    execl(entry->pw_shell, entry->pw_shell, NULL);
 }

initrd/etc/passwd

@@ -1,2 +0,0 @@
-root:toor:0:0:Administrator:/:/bin/sh
-selene:moon:1000:1000:User:/home/selene:/bin/sh

kernel/src/fs/VFS.cpp

@@ -86,14 +86,4 @@ namespace VFS
 
         return inode->mode() & S_IROTH;
     }
-
-    bool is_setuid(SharedPtr<Inode> inode)
-    {
-        return inode->mode() & S_ISUID;
-    }
-
-    bool is_setgid(SharedPtr<Inode> inode)
-    {
-        return inode->mode() & S_ISGID;
-    }
 }

kernel/src/fs/VFS.h

@@ -178,8 +178,6 @@ namespace VFS
     bool can_execute(SharedPtr<Inode> inode, Credentials auth);
     bool can_read(SharedPtr<Inode> inode, Credentials auth);
     bool can_write(SharedPtr<Inode> inode, Credentials auth);
-    bool is_setuid(SharedPtr<Inode> inode);
-    bool is_setgid(SharedPtr<Inode> inode);
 
     Inode& root_inode();
 }

kernel/src/sys/exec.cpp

@@ -76,9 +76,6 @@ Result<u64> sys_execve(Registers* regs, SyscallArgs args)
 
     MMU::delete_userspace_page_directory(current->directory);
 
-    if (VFS::is_setuid(inode)) current->auth.euid = current->auth.suid = inode->uid();
-    if (VFS::is_setgid(inode)) current->auth.egid = current->auth.sgid = inode->gid();
-
     current->name = path.chars();
 
     image->apply(current);

libc/CMakeLists.txt

@@ -16,7 +16,6 @@ set(SOURCES
     src/dirent.cpp
     src/setjmp.cpp
     src/env.cpp
-    src/pwd.cpp
     src/sys/stat.cpp
     src/sys/mman.cpp
     src/sys/wait.cpp

libc/include/pwd.h

@@ -1,43 +0,0 @@
-/* pwd.h: Password file parsing. */
-
-#ifndef _PWD_H
-#define _PWD_H
-
-#include <sys/types.h>
-
-struct passwd
-{
-    char* pw_name;
-    char* pw_passwd;
-    uid_t pw_uid;
-    gid_t pw_gid;
-    char* pw_gecos;
-    char* pw_dir;
-    char* pw_shell;
-};
-
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-    /* Read the next entry from the password file. */
-    struct passwd* getpwent(void);
-
-    /* Find the entry with a matching username in the password file. */
-    struct passwd* getpwnam(const char* name);
-
-    /* Find the entry with a matching user ID in the password file. */
-    struct passwd* getpwuid(uid_t uid);
-
-    /* Rewind the password file. */
-    void setpwent(void);
-
-    /* End password file parsing. */
-    void endpwent(void);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

libc/src/pwd.cpp

@@ -1,109 +0,0 @@
-#include <pwd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-static struct passwd pwd;
-static FILE* f { nullptr };
-static char buf[4096];
-
-extern "C"
-{
-    struct passwd* getpwent()
-    {
-        if (!f)
-        {
-            f = fopen("/etc/passwd", "r");
-            if (!f) return nullptr;
-        }
-
-        while (true)
-        {
-            char* rc = fgets(buf, sizeof(buf), f);
-            if (!rc) return nullptr;
-
-            char* name = strtok(rc, ":\n");
-            if (!name) continue;
-
-            char* passwd = strtok(nullptr, ":\n");
-            if (!passwd) continue;
-
-            char* uid = strtok(nullptr, ":\n");
-            if (!uid) continue;
-
-            char* gid = strtok(nullptr, ":\n");
-            if (!gid) continue;
-
-            char* gecos = strtok(nullptr, ":\n");
-            if (!gecos) continue;
-
-            char* dir = strtok(nullptr, ":\n");
-            if (!dir) continue;
-
-            char* shell = strtok(nullptr, ":\n");
-            if (!shell) continue;
-
-            pwd.pw_name = name;
-            pwd.pw_passwd = passwd;
-            pwd.pw_uid = (uid_t)strtoul(uid, NULL, 10);
-            pwd.pw_gid = (gid_t)strtoul(gid, NULL, 10);
-            pwd.pw_gecos = gecos;
-            pwd.pw_dir = dir;
-            pwd.pw_shell = shell;
-
-            return &pwd;
-        }
-    }
-
-    struct passwd* getpwnam(const char* name)
-    {
-        setpwent();
-
-        struct passwd* entry;
-
-        while ((entry = getpwent()))
-        {
-            if (!strcmp(entry->pw_name, name))
-            {
-                endpwent();
-                return entry;
-            }
-        }
-
-        endpwent();
-        return entry;
-    }
-
-    struct passwd* getpwuid(uid_t uid)
-    {
-        setpwent();
-
-        struct passwd* entry;
-
-        while ((entry = getpwent()))
-        {
-            if (entry->pw_uid == uid)
-            {
-                endpwent();
-                return entry;
-            }
-        }
-
-        endpwent();
-        return entry;
-    }
-
-    void setpwent()
-    {
-        if (f) rewind(f);
-    }
-
-    void endpwent()
-    {
-        if (f)
-        {
-            fclose(f);
-            f = nullptr;
-        }
-    }
-}