[Libc] add C stubs for getpwnam_r and getpwuid_r

headers/header_spec.txt

@@ -286,6 +286,7 @@ share/libc/netinet/tcp.h: CEA_LGPL
 share/libc/nl_types.h: CEA_LGPL
 share/libc/poll.h: CEA_LGPL
 share/libc/pthread.h: CEA_LGPL
+share/libc/pwd.c: CEA_LGPL
 share/libc/pwd.h: CEA_LGPL
 share/libc/regex.h: CEA_LGPL
 share/libc/resolv.h: CEA_LGPL

share/libc/__fc_runtime.c

@@ -33,6 +33,7 @@
 #include "math.c"
 #include "netdb.c"
 #include "netinet/in.c"
+#include "pwd.c"
 #include "signal.c"
 #include "stdatomic.c"
 #include "stdio.c"

share/libc/pwd.c

+/**************************************************************************/
+/*                                                                        */
+/*  This file is part of Frama-C.                                         */
+/*                                                                        */
+/*  Copyright (C) 2007-2022                                               */
+/*    CEA (Commissariat à l'énergie atomique et aux énergies              */
+/*         alternatives)                                                  */
+/*                                                                        */
+/*  you can redistribute it and/or modify it under the terms of the GNU   */
+/*  Lesser General Public License as published by the Free Software       */
+/*  Foundation, version 2.1.                                              */
+/*                                                                        */
+/*  It is distributed in the hope that it will be useful,                 */
+/*  but WITHOUT ANY WARRANTY; without even the implied warranty of        */
+/*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         */
+/*  GNU Lesser General Public License for more details.                   */
+/*                                                                        */
+/*  See the GNU Lesser General Public License version 2.1                 */
+/*  for more details (enclosed in the file licenses/LGPLv2.1).            */
+/*                                                                        */
+/**************************************************************************/
+
+#include "__fc_builtin.h"
+#include "errno.h"
+#include "pwd.h"
+#include "string.h"
+
+__PUSH_FC_STDLIB
+
+char __fc_getpw_pw_name[64];
+char __fc_getpw_pw_passwd[64];
+char __fc_getpw_pw_gecos[64];
+char __fc_getpw_pw_dir[64];
+char __fc_getpw_pw_shell[64];
+
+static int __fc_getpw_init; // used to initialize the __fc_getpw* strings
+
+#define COPY_FIELD(fieldname)                   \
+  len = strlen(__fc_pwd.fieldname);             \
+  if (remaining <= len) {                       \
+    *result = NULL;                             \
+    return ERANGE;                              \
+  }                                             \
+  strcpy(buf, __fc_pwd.fieldname);              \
+  buf[len] = 0;                                 \
+  pwd->fieldname = buf;                         \
+  buf += len + 1;                               \
+  remaining -= len
+
+// Common code between getpwman_r and getpwuid_r
+static int __fc_getpw_r(struct passwd *pwd, char *buf,
+                        size_t buflen, struct passwd **result) {
+  // initialize global strings (only during first execution)
+  if (!__fc_getpw_init) {
+    __fc_getpw_init = 1;
+    Frama_C_make_unknown(__fc_getpw_pw_name, 63);
+    __fc_getpw_pw_name[63] = 0;
+    Frama_C_make_unknown(__fc_getpw_pw_passwd, 63);
+    __fc_getpw_pw_passwd[63] = 0;
+    Frama_C_make_unknown(__fc_getpw_pw_gecos, 63);
+    __fc_getpw_pw_gecos[63] = 0;
+    Frama_C_make_unknown(__fc_getpw_pw_dir, 63);
+    __fc_getpw_pw_dir[63] = 0;
+    Frama_C_make_unknown(__fc_getpw_pw_shell, 63);
+    __fc_getpw_pw_shell[63] = 0;
+  }
+
+  // simulate one of several possible errors, or "not found"
+  if (Frama_C_interval(0, 1)) {
+    // 'error or not found' case
+    *result = NULL;
+    if (Frama_C_interval(0, 1)) return EIO;
+    if (Frama_C_interval(0, 1)) return EMFILE;
+    if (Frama_C_interval(0, 1)) return ENFILE;
+    // Note: POSIX only specifies these values, but several implementations
+    // return others, including ENOENT, EBADF, ESRCH, EWOULDBLOCK, EPERM.
+    return 0;
+  } else {
+    // 'found without errors' case
+    size_t len, remaining = buflen;
+    // copy string fields to buf
+    COPY_FIELD(pw_name);
+    COPY_FIELD(pw_passwd);
+    COPY_FIELD(pw_gecos);
+    COPY_FIELD(pw_dir);
+    COPY_FIELD(pw_shell);
+    pwd->pw_uid = Frama_C_unsigned_int_interval(0, UINT_MAX);
+    pwd->pw_gid = Frama_C_unsigned_int_interval(0, UINT_MAX);
+    *result = pwd;
+    return 0;
+  }
+}
+
+int getpwnam_r(const char *name, struct passwd *pwd,
+               char *buf, size_t buflen, struct passwd **result) {
+  //@ assert valid_read_string(name);
+  return __fc_getpw_r(pwd, buf, buflen, result);
+}
+
+int getpwuid_r(uid_t uid, struct passwd *pwd,
+               char *buf, size_t buflen, struct passwd **result) {
+  return __fc_getpw_r(pwd, buf, buflen, result);
+}
+
+__POP_FC_STDLIB

src/plugins/value/utils/library_functions.ml

@@ -78,6 +78,8 @@ let unsupported_specifications =
     "getaddrinfo", "netdb.c";
     "getenv", "stdlib.c";
     "getline", "stdio.c";
+    "getpwnam_r", "pwd.c";
+    "getpwuid_r", "pwd.c";
     "glob", "glob.c";
     "globfree", "glob.c";
     "posix_memalign", "stdlib.c";