Libraries: Move to Userland/Libraries/

1 files changed, 189 insertions, 0 deletions

diff --git a/Userland/Libraries/LibC/pwd.cpp b/Userland/Libraries/LibC/pwd.cpp
new file mode 100644
index 0000000000..7af0d67d68
--- /dev/null
+++ b/Userland/Libraries/LibC/pwd.cpp
@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/String.h>
+#include <AK/Vector.h>
+#include <errno_numbers.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+extern "C" {
+
+static FILE* s_stream = nullptr;
+static unsigned s_line_number = 0;
+static struct passwd s_passwd_entry;
+
+static String s_name;
+static String s_passwd;
+static String s_gecos;
+static String s_dir;
+static String s_shell;
+
+void setpwent()
+{
+    s_line_number = 0;
+    if (s_stream) {
+        rewind(s_stream);
+    } else {
+        s_stream = fopen("/etc/passwd", "r");
+        if (!s_stream) {
+            perror("open /etc/passwd");
+        }
+    }
+}
+
+void endpwent()
+{
+    s_line_number = 0;
+    if (s_stream) {
+        fclose(s_stream);
+        s_stream = nullptr;
+    }
+
+    memset(&s_passwd_entry, 0, sizeof(s_passwd_entry));
+
+    s_name = {};
+    s_passwd = {};
+    s_gecos = {};
+    s_dir = {};
+    s_shell = {};
+}
+
+struct passwd* getpwuid(uid_t uid)
+{
+    setpwent();
+    while (auto* pw = getpwent()) {
+        if (pw->pw_uid == uid)
+            return pw;
+    }
+    return nullptr;
+}
+
+struct passwd* getpwnam(const char* name)
+{
+    setpwent();
+    while (auto* pw = getpwent()) {
+        if (!strcmp(pw->pw_name, name))
+            return pw;
+    }
+    return nullptr;
+}
+
+static bool parse_pwddb_entry(const String& line)
+{
+    auto parts = line.split_view(':', true);
+    if (parts.size() != 7) {
+        fprintf(stderr, "getpwent(): Malformed entry on line %u\n", s_line_number);
+        return false;
+    }
+
+    s_name = parts[0];
+    s_passwd = parts[1];
+    auto& uid_string = parts[2];
+    auto& gid_string = parts[3];
+    s_gecos = parts[4];
+    s_dir = parts[5];
+    s_shell = parts[6];
+
+    auto uid = uid_string.to_uint();
+    if (!uid.has_value()) {
+        fprintf(stderr, "getpwent(): Malformed UID on line %u\n", s_line_number);
+        return false;
+    }
+    auto gid = gid_string.to_uint();
+    if (!gid.has_value()) {
+        fprintf(stderr, "getpwent(): Malformed GID on line %u\n", s_line_number);
+        return false;
+    }
+
+    s_passwd_entry.pw_name = const_cast<char*>(s_name.characters());
+    s_passwd_entry.pw_passwd = const_cast<char*>(s_passwd.characters());
+    s_passwd_entry.pw_uid = uid.value();
+    s_passwd_entry.pw_gid = gid.value();
+    s_passwd_entry.pw_gecos = const_cast<char*>(s_gecos.characters());
+    s_passwd_entry.pw_dir = const_cast<char*>(s_dir.characters());
+    s_passwd_entry.pw_shell = const_cast<char*>(s_shell.characters());
+
+    return true;
+}
+
+struct passwd* getpwent()
+{
+    if (!s_stream)
+        setpwent();
+
+    while (true) {
+        if (!s_stream || feof(s_stream))
+            return nullptr;
+
+        if (ferror(s_stream)) {
+            fprintf(stderr, "getpwent(): Read error: %s\n", strerror(ferror(s_stream)));
+            return nullptr;
+        }
+
+        char buffer[1024];
+        ++s_line_number;
+        char* s = fgets(buffer, sizeof(buffer), s_stream);
+
+        // Silently tolerate an empty line at the end.
+        if ((!s || !s[0]) && feof(s_stream))
+            return nullptr;
+
+        String line(s, Chomp);
+        if (parse_pwddb_entry(line))
+            return &s_passwd_entry;
+        // Otherwise, proceed to the next line.
+    }
+}
+
+int putpwent(const struct passwd* p, FILE* stream)
+{
+    if (!p || !stream || !p->pw_passwd || !p->pw_name || !p->pw_dir || !p->pw_gecos || !p->pw_shell) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    auto is_valid_field = [](const char* str) {
+        return str && !strpbrk(str, ":\n");
+    };
+
+    if (!is_valid_field(p->pw_name) || !is_valid_field(p->pw_dir) || !is_valid_field(p->pw_gecos) || !is_valid_field(p->pw_shell)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    int nwritten = fprintf(stream, "%s:%s:%u:%u:%s,,,:%s:%s\n", p->pw_name, p->pw_passwd, p->pw_uid, p->pw_gid, p->pw_gecos, p->pw_dir, p->pw_shell);
+    if (!nwritten || nwritten < 0) {
+        errno = ferror(stream);
+        return -1;
+    }
+
+    return 0;
+}
+}