diff options
| -rw-r--r-- | winsup/doc/utils.xml | 50 | ||||
| -rw-r--r-- | winsup/utils/Makefile.am | 1 | ||||
| -rw-r--r-- | winsup/utils/newgrp.c | 200 |
3 files changed, 212 insertions, 39 deletions
diff --git a/winsup/doc/utils.xml b/winsup/doc/utils.xml index 8959880..927dc7c 100644 --- a/winsup/doc/utils.xml +++ b/winsup/doc/utils.xml @@ -1939,6 +1939,56 @@ D: on /d type fat (binary,user,noumount) </refsect1> </refentry> + <refentry id="newgrp"> + <refmeta> + <refentrytitle>newgrp</refentrytitle> + <manvolnum>1</manvolnum> + <refmiscinfo class="manual">Cygwin Utilities</refmiscinfo> + </refmeta> + + <refnamediv> + <refname>newgrp</refname> + <refpurpose>change primary group for a command</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>newgrp</command> + <arg choice="opt">-</arg> + <arg choice="opt"><replaceable>group</replaceable></arg> + <arg><replaceable>command</replaceable> + <arg rep="repeat"><replaceable>args</replaceable></arg> + </arg> + </cmdsynopsis> + </refsynopsisdiv> + + <refsect1 id="newgrp-desc"> + <title>Description</title> + <para><command>newgrp</command> changes the primary group for a + command.</para> + + <para>If the '-' flag is given as first argument, the user's environment + will be reinitialized as though the user had logged in, otherwise the + current environment, including current working directory, remains + unchanged.</para> + + <para><command>newgrp</command> changes the current primary group to the + named group, or to the default group listed in /etc/passwd if no group + name is given.</para> + + <para>By default, the user's standard shell is started, called as login + shell if the '-' flag has been specified. If a group has been given + as argument, a command and its arguments can be specified on the + command line.</para> + + <para>Please note that setting the primary group to any arbitrary group + is no privileged operation on Windows. However, if this group is not + in your current user token, or if the group is in your user token but + marked as <literal>deny-only</literal>, no additional permissions can + be obtained by setting this group as primary group.</para> + </refsect1> + </refentry> + <refentry id="passwd"> <refmeta> <refentrytitle>passwd</refentrytitle> diff --git a/winsup/utils/Makefile.am b/winsup/utils/Makefile.am index 75da116..d4d5638 100644 --- a/winsup/utils/Makefile.am +++ b/winsup/utils/Makefile.am @@ -87,6 +87,7 @@ pldd_LDADD = $(LDADD) -lpsapi profiler_CXXFLAGS = -I$(srcdir) -idirafter ${top_srcdir}/cygwin/local_includes -idirafter ${top_srcdir}/cygwin/include $(AM_CXXFLAGS) profiler_LDADD = $(LDADD) -lntdll cygps_LDADD = $(LDADD) -lpsapi -lntdll +newgrp_LDADD = $(LDADD) -luserenv if CROSS_BOOTSTRAP SUBDIRS = mingw diff --git a/winsup/utils/newgrp.c b/winsup/utils/newgrp.c index 012c318..8858635 100644 --- a/winsup/utils/newgrp.c +++ b/winsup/utils/newgrp.c @@ -6,86 +6,204 @@ This software is a copyrighted work licensed under the terms of the Cygwin license. Please consult the file "CYGWIN_LICENSE" for details. */ +#define _GNU_SOURCE 1 #include <stdio.h> #include <stdlib.h> +#include <stdbool.h> #include <unistd.h> #include <errno.h> #include <ctype.h> #include <string.h> +#include <wchar.h> +#include <locale.h> #include <grp.h> #include <pwd.h> +#include <sys/cygwin.h> +#include <w32api/windows.h> +#include <w32api/userenv.h> + +#define PATH_PREFIX "PATH=/usr/bin:" + +char * +create_env_var (const char *name, const char *val) +{ + char *var, *cp; + + var = (char *) calloc (strlen (name) + strlen (val) + 2, sizeof (char *)); + cp = stpcpy (var, name); + *cp++ = '='; + stpcpy (cp, val); + return var; +} + +char ** +create_child_env (struct passwd *pw) +{ + char **posix_env, *cp; + wchar_t *win_env, *wep; + size_t max_cnt = 0; + size_t idx = 0; + HANDLE token; + + /* Fecth Windows default environment of current user */ + if (!OpenProcessToken (GetCurrentProcess (), + TOKEN_QUERY | TOKEN_DUPLICATE, &token)) + { + fprintf (stderr, "%s: creating environment failed with error %u " + "(OpenProcessToken)\n", + program_invocation_short_name, GetLastError ()); + return NULL; + } + if (!CreateEnvironmentBlock ((PVOID *) &win_env, token, FALSE)) + { + fprintf (stderr, "%s: creating environment failed with error %u " + "(CreateEnvironmentBlock)\n", + program_invocation_short_name, GetLastError ()); + CloseHandle (token); + return NULL; + } + CloseHandle (token); + /* Convert to Posix env */ + for (wep = win_env; *wep; wep = wcschr (wep, '\0') + 1) + ++max_cnt; + posix_env = (char **) calloc (max_cnt + 6, sizeof (char *)); + if (!posix_env) + { + fprintf (stderr, "%s: allocating environment failed: %s\n", + program_invocation_short_name, strerror (errno)); + return NULL; + } + for (wep = win_env; *wep; ++idx, wep = wcschr (wep, '\0') + 1) + { + /* For $PATH we must prepend /usr/bin to the converted POSIX path list */ + if (!wcsncasecmp (wep, L"PATH=", 5)) + { + size_t len = cygwin_conv_path_list (CCP_WIN_W_TO_POSIX, + wep + 5, NULL, 0); + posix_env[idx] = (char *) calloc (sizeof (PATH_PREFIX) + len, + sizeof (char *)); + if (!posix_env[idx]) + { + fprintf (stderr, "%s: allocating environment failed: %s\n", + program_invocation_short_name, strerror (errno)); + return NULL; + } + cp = stpcpy (posix_env[idx], PATH_PREFIX); + cygwin_conv_path_list (CCP_WIN_W_TO_POSIX, wep + 5, cp, len); + } + else + { + size_t len = wcstombs (NULL, wep, 0); + + if (len == (size_t) -1) + { + fprintf (stderr, + "%s: invalid char in environment variable: %ls\n", + program_invocation_short_name, wep); + return NULL; + } + posix_env[idx] = (char *) calloc (len + 1, sizeof (char *)); + if (!posix_env[idx]) + { + fprintf (stderr, "%s: allocating environment failed: %s\n", + program_invocation_short_name, strerror (errno)); + return NULL; + } + wcstombs (posix_env[idx], wep, len + 1); + } + } + DestroyEnvironmentBlock (win_env); + /* Add USER, LOGNAME, HOME, LANG, just like sshd */ + posix_env[idx++] = create_env_var ("USER", pw->pw_name); + posix_env[idx++] = create_env_var ("LOGNAME", pw->pw_name); + posix_env[idx++] = create_env_var ("HOME", pw->pw_dir); + cp = getenv("LANG"); + if (cp) + posix_env[idx] = create_env_var ("LANG", cp); + cp = getenv("TERM"); + if (cp) + posix_env[idx] = create_env_var ("TERM", cp); + return posix_env; +} + int main (int argc, const char **argv) { + const char *cmd, **cmd_av, *fake_av[2]; + struct passwd *pw; struct group *gr; + char **child_env; + bool new_child_env = false; gid_t gid; - const char *cmd; - const char **cmd_av; - const char *fake_av[2]; - /* TODO: Implement '-' option */ - /* TODO: Add command description to documentation */ + setlocale (LC_ALL, ""); - if (argc < 2 || argv[1][0] == '-') + if (argc < 2 || (argv[1][0] == '-' && argv[1][1])) { - fprintf (stderr, - "Usage: %1$s group [command [args...]]\n" - "\n" - "%1$s changes the current primary group for a command.\n" - "The primary group must be member of the supplementary group\n" - "list of the user.\n" - "The command and its arguments are specified on the command\n" - "line. Default is the user's standard shell.\n", + fprintf (stderr, "Usage: %s [-] [group] [command [args...]]\n", program_invocation_short_name); return 1; } - if (isdigit ((int) argv[1][0])) + + /* Check if we have to regenerate a stock environment */ + if (argv[1][0] == '-') { - char *e = NULL; + new_child_env = true; + --argc; + ++argv; + } - gid = strtol (argv[1], &e, 10); - if (e && *e != '\0') - { - fprintf (stderr, "%s: invalid gid `%s'\n", - program_invocation_short_name, argv[1]); - return 2; - } - gr = getgrgid (gid); - if (!gr) - { - fprintf (stderr, "%s: unknown group gid `%u'\n", - program_invocation_short_name, gid); - return 2; - } + pw = getpwuid (getuid ()); + + /* Fetch group */ + if (argv[1] == NULL) + { + gid = pw->pw_gid; } else { gr = getgrnam (argv[1]); if (!gr) { - fprintf (stderr, "%s: unknown group name `%s'\n", + fprintf (stderr, "%s: group '%s' does not exist\n", program_invocation_short_name, argv[1]); return 2; } gid = gr->gr_gid; + --argc; + ++argv; } + + /* Set primary group */ if (setgid (gid) != 0) { - fprintf (stderr, "%s: can't switch primary group to `%s'\n", + fprintf (stderr, "%s: can't switch primary group to '%s'\n", program_invocation_short_name, argv[1]); return 2; } - argc -= 2; - argv += 2; + + /* Maybe generate stock child environment */ + if (!new_child_env) + child_env = environ; + else + { + child_env = create_child_env (pw); + if (!child_env) + return 3; + chdir (pw->pw_dir); + } + + /* Set argc/argv for execvpe */ + --argc; + ++argv; if (argc < 1) { - struct passwd *pw = getpwuid (getuid ()); if (!pw) cmd = "/usr/bin/bash"; else cmd = pw->pw_shell; - fake_av[0] = cmd; + fake_av[0] = new_child_env ? "-" : cmd; fake_av[1] = NULL; cmd_av = fake_av; } @@ -94,8 +212,12 @@ main (int argc, const char **argv) cmd = argv[0]; cmd_av = argv; } - execvp (cmd, (char **) cmd_av); - fprintf (stderr, "%s: failed to start `%s': %s\n", + + /* Exec child process */ + execvpe (cmd, (char **) cmd_av, child_env); + + /* Oops */ + fprintf (stderr, "%s: failed to start '%s': %s\n", program_invocation_short_name, cmd, strerror (errno)); - return 3; + return 4; } |