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-rw-r--r--src/sesh.c489
1 files changed, 489 insertions, 0 deletions
diff --git a/src/sesh.c b/src/sesh.c
new file mode 100644
index 0000000..44faa11
--- /dev/null
+++ b/src/sesh.c
@@ -0,0 +1,489 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2008, 2010-2018, 2020-2022 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <time.h>
+#include <unistd.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include <compat/stdbool.h>
+#endif /* HAVE_STDBOOL_H */
+#ifdef HAVE_GETOPT_LONG
+# include <getopt.h>
+# else
+# include <compat/getopt.h>
+#endif /* HAVE_GETOPT_LONG */
+
+#include <sudo.h>
+#include <sudo_exec.h>
+#include <sudo_edit.h>
+
+enum sesh_mode {
+ SESH_RUN_COMMAND,
+ SESH_EDIT_CREATE,
+ SESH_EDIT_INSTALL
+};
+
+static const char short_opts[] = "+cd:e:ihnw:";
+static struct option long_opts[] = {
+ { "edit-create", no_argument, NULL, 'c' },
+ { "directory", required_argument, NULL, 'd' },
+ { "execfd", required_argument, NULL, 'e' },
+ { "edit-install", no_argument, NULL, 'i' },
+ { "no-dereference", no_argument, NULL, 'h' },
+ { "noexec", no_argument, NULL, 'n' },
+ { "edit-checkdir", required_argument, NULL, 'w' },
+ { NULL, no_argument, NULL, '\0' },
+};
+
+sudo_dso_public int main(int argc, char *argv[], char *envp[]);
+
+static int sesh_sudoedit(enum sesh_mode mode, int flags, char *user, int argc,
+ char *argv[]);
+
+sudo_noreturn void
+usage(void)
+{
+ (void)fprintf(stderr,
+ "usage: %s [-n] [-d directory] [-e fd] command [...]\n"
+ " %s [-cih] [-w uid:gids] file [...]\n",
+ getprogname(), getprogname());
+ exit(EXIT_FAILURE);
+}
+
+/*
+ * Exit codes defined in sudo_exec.h:
+ * SESH_SUCCESS (0) ... successful operation
+ * SESH_ERR_FAILURE (1) ... unspecified error
+ * SESH_ERR_INVALID (30) ... invalid -e arg value
+ * SESH_ERR_BAD_PATHS (31) ... odd number of paths
+ * SESH_ERR_NO_FILES (32) ... copy error, no files copied
+ * SESH_ERR_SOME_FILES (33) ... copy error, no files copied
+ */
+int
+main(int argc, char *argv[], char *envp[])
+{
+ enum sesh_mode mode = SESH_RUN_COMMAND;
+ const char *errstr, *rundir = NULL;
+ unsigned int flags = CD_SUDOEDIT_FOLLOW;
+ char *edit_user = NULL;
+ int ch, ret, fd = -1;
+ debug_decl(main, SUDO_DEBUG_MAIN);
+
+ initprogname(argc > 0 ? argv[0] : "sesh");
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE_NAME, LOCALEDIR);
+ textdomain(PACKAGE_NAME);
+
+ while ((ch = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
+ switch (ch) {
+ case 'c':
+ if (mode != SESH_RUN_COMMAND) {
+ sudo_warnx("%s",
+ U_("Only one of the -c or -i options may be specified"));
+ usage();
+ }
+ mode = SESH_EDIT_CREATE;
+ break;
+ case 'd':
+ rundir = optarg;
+ if (*rundir == '+') {
+ SET(flags, CD_CWD_OPTIONAL);
+ rundir++;
+ }
+ break;
+ case 'e':
+ fd = sudo_strtonum(optarg, 0, INT_MAX, &errstr);
+ if (errstr != NULL)
+ sudo_fatalx(U_("invalid file descriptor number: %s"), optarg);
+ break;
+ case 'i':
+ if (mode != SESH_RUN_COMMAND) {
+ sudo_warnx("%s",
+ U_("Only one of the -c or -i options may be specified"));
+ usage();
+ }
+ mode = SESH_EDIT_INSTALL;
+ break;
+ case 'h':
+ CLR(flags, CD_SUDOEDIT_FOLLOW);
+ break;
+ case 'n':
+ SET(flags, CD_NOEXEC);
+ break;
+ case 'w':
+ SET(flags, CD_SUDOEDIT_CHECKDIR);
+ edit_user = optarg;
+ break;
+ default:
+ usage();
+ /* NOTREACHED */
+ }
+ }
+ argc -= optind;
+ argv += optind;
+ if (argc == 0)
+ usage();
+
+ /* Read sudo.conf and initialize the debug subsystem. */
+ if (sudo_conf_read(NULL, SUDO_CONF_DEBUG) == -1)
+ return EXIT_FAILURE;
+ sudo_debug_register(getprogname(), NULL, NULL,
+ sudo_conf_debug_files(getprogname()), -1);
+
+ if (mode != SESH_RUN_COMMAND) {
+ if (rundir != NULL) {
+ sudo_warnx(U_("The -%c option may not be used in edit mode."), 'd');
+ usage();
+ }
+ if (fd != -1) {
+ sudo_warnx(U_("The -%c option may not be used in edit mode."), 'e');
+ usage();
+ }
+ if (ISSET(flags, CD_NOEXEC)) {
+ sudo_warnx(U_("The -%c option may not be used in edit mode."), 'n');
+ usage();
+ }
+ ret = sesh_sudoedit(mode, flags, edit_user, argc, argv);
+ } else {
+ bool login_shell;
+ char *cmnd;
+
+ if (!ISSET(flags, CD_SUDOEDIT_FOLLOW)) {
+ sudo_warnx(U_("The -%c option may only be used in edit mode."),
+ 'h');
+ usage();
+ }
+ if (edit_user != NULL) {
+ sudo_warnx(U_("The -%c option may only be used in edit mode."),
+ 'w');
+ usage();
+ }
+
+ /* If the first char of argv[0] is '-', we are running a login shell. */
+ login_shell = argv[0][0] == '-';
+
+ /* We must change the directory in sesh after the context changes. */
+ if (rundir != NULL && chdir(rundir) == -1) {
+ sudo_warnx(U_("unable to change directory to %s"), rundir);
+ if (!ISSET(flags, CD_CWD_OPTIONAL))
+ return EXIT_FAILURE;
+ }
+
+ /* Make a copy of the command to execute. */
+ if ((cmnd = strdup(argv[0])) == NULL)
+ sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+
+ /* If invoked as a login shell, modify argv[0] accordingly. */
+ if (login_shell) {
+ char *cp = strrchr(argv[0], '/');
+ if (cp != NULL) {
+ *cp = '-';
+ argv[0] = cp;
+ }
+ }
+ sudo_execve(fd, cmnd, argv, envp, -1, flags);
+ sudo_warn(U_("unable to execute %s"), cmnd);
+ ret = SESH_ERR_FAILURE;
+ }
+ sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys, ret);
+ _exit(ret);
+}
+
+/*
+ * Destructively parse a string in the format:
+ * uid:gid:groups,...
+ *
+ * On success, fills in ud and returns true, else false.
+ */
+static bool
+parse_user(char *userstr, struct sudo_cred *cred)
+{
+ char *cp, *ep;
+ const char *errstr;
+ debug_decl(parse_user, SUDO_DEBUG_EDIT);
+
+ /* UID */
+ cp = userstr;
+ if ((ep = strchr(cp, ':')) == NULL) {
+ sudo_warnx(U_("%s: %s"), cp, U_("invalid value"));
+ debug_return_bool(false);
+ }
+ *ep++ = '\0';
+ cred->uid = cred->euid = sudo_strtoid(cp, &errstr);
+ if (errstr != NULL) {
+ sudo_warnx(U_("%s: %s"), cp, errstr);
+ debug_return_bool(false);
+ }
+
+ /* GID */
+ cp = ep;
+ if ((ep = strchr(cp, ':')) == NULL) {
+ sudo_warnx(U_("%s: %s"), cp, U_("invalid value"));
+ debug_return_bool(false);
+ }
+ *ep++ = '\0';
+ cred->gid = cred->egid = sudo_strtoid(cp, &errstr);
+ if (errstr != NULL) {
+ sudo_warnx(U_("%s: %s"), cp, errstr);
+ debug_return_bool(false);
+ }
+
+ /* group vector */
+ cp = ep;
+ cred->ngroups = sudo_parse_gids(cp, NULL, &cred->groups);
+ if (cred->ngroups == -1)
+ debug_return_bool(false);
+
+ debug_return_bool(true);
+}
+
+static int
+sesh_edit_create_tfiles(int edit_flags, struct sudo_cred *user_cred,
+ struct sudo_cred *run_cred, int argc, char *argv[])
+{
+ int i, fd_src = -1, fd_dst = -1;
+ struct timespec times[2];
+ struct stat sb;
+ debug_decl(sesh_edit_create_tfiles, SUDO_DEBUG_EDIT);
+
+ for (i = 0; i < argc - 1; i += 2) {
+ char *path_src = argv[i];
+ const char *path_dst = argv[i + 1];
+
+ /*
+ * Try to open the source file for reading.
+ * If it doesn't exist, we'll create an empty destination file.
+ */
+ fd_src = sudo_edit_open(path_src, O_RDONLY,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH, edit_flags, user_cred, run_cred);
+ if (fd_src == -1) {
+ if (errno != ENOENT) {
+ if (errno == ELOOP) {
+ sudo_warnx(U_("%s: editing symbolic links is not "
+ "permitted"), path_src);
+ } else if (errno == EISDIR) {
+ sudo_warnx(U_("%s: editing files in a writable directory "
+ "is not permitted"), path_src);
+ } else {
+ sudo_warn("%s", path_src);
+ }
+ goto cleanup;
+ }
+ /* New file, verify parent dir exists and is not writable. */
+ if (!sudo_edit_parent_valid(path_src, edit_flags, user_cred, run_cred))
+ goto cleanup;
+ }
+ if (fd_src == -1) {
+ /* New file. */
+ memset(&sb, 0, sizeof(sb));
+ } else if (fstat(fd_src, &sb) == -1 || !S_ISREG(sb.st_mode)) {
+ sudo_warnx(U_("%s: not a regular file"), path_src);
+ goto cleanup;
+ }
+
+ /*
+ * Create temporary file using O_EXCL to ensure that temporary
+ * files are created by us and that we do not open any symlinks.
+ */
+ fd_dst = open(path_dst, O_WRONLY|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR);
+ if (fd_dst == -1) {
+ sudo_warn("%s", path_dst);
+ goto cleanup;
+ }
+
+ if (fd_src != -1) {
+ if (sudo_copy_file(path_src, fd_src, -1, path_dst, fd_dst, -1) == -1)
+ goto cleanup;
+ close(fd_src);
+ }
+
+ /* Make mtime on temp file match src (sb filled in above). */
+ mtim_get(&sb, times[0]);
+ times[1].tv_sec = times[0].tv_sec;
+ times[1].tv_nsec = times[0].tv_nsec;
+ if (futimens(fd_dst, times) == -1) {
+ if (utimensat(AT_FDCWD, path_dst, times, 0) == -1)
+ sudo_warn("%s", path_dst);
+ }
+ close(fd_dst);
+ fd_dst = -1;
+ }
+ debug_return_int(SESH_SUCCESS);
+
+cleanup:
+ /* Remove temporary files. */
+ for (i = 0; i < argc - 1; i += 2)
+ unlink(argv[i + 1]);
+ if (fd_src != -1)
+ close(fd_src);
+ if (fd_dst != -1)
+ close(fd_dst);
+ debug_return_int(SESH_ERR_NO_FILES);
+}
+
+static int
+sesh_edit_copy_tfiles(int edit_flags, struct sudo_cred *user_cred,
+ struct sudo_cred *run_cred, int argc, char *argv[])
+{
+ int i, ret = SESH_SUCCESS;
+ int fd_src = -1, fd_dst = -1;
+ debug_decl(sesh_edit_copy_tfiles, SUDO_DEBUG_EDIT);
+
+ for (i = 0; i < argc - 1; i += 2) {
+ const char *path_src = argv[i];
+ char *path_dst = argv[i + 1];
+ off_t len_src, len_dst;
+ struct stat sb;
+
+ /* Open temporary file for reading. */
+ if (fd_src != -1)
+ close(fd_src);
+ fd_src = open(path_src, O_RDONLY|O_NONBLOCK|O_NOFOLLOW);
+ if (fd_src == -1) {
+ sudo_warn("%s", path_src);
+ ret = SESH_ERR_SOME_FILES;
+ continue;
+ }
+ /* Make sure the temporary file is safe and has the proper owner. */
+ if (!sudo_check_temp_file(fd_src, path_src, run_cred->uid, &sb)) {
+ sudo_warnx(U_("contents of edit session left in %s"), path_src);
+ ret = SESH_ERR_SOME_FILES;
+ continue;
+ }
+ (void) fcntl(fd_src, F_SETFL, fcntl(fd_src, F_GETFL, 0) & ~O_NONBLOCK);
+
+ /* Create destination file. */
+ if (fd_dst != -1)
+ close(fd_dst);
+ fd_dst = sudo_edit_open(path_dst, O_WRONLY|O_CREAT,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH, edit_flags, user_cred, run_cred);
+ if (fd_dst == -1) {
+ if (errno == ELOOP) {
+ sudo_warnx(U_("%s: editing symbolic links is not "
+ "permitted"), path_dst);
+ } else if (errno == EISDIR) {
+ sudo_warnx(U_("%s: editing files in a writable directory "
+ "is not permitted"), path_dst);
+ } else {
+ sudo_warn("%s", path_dst);
+ }
+ sudo_warnx(U_("contents of edit session left in %s"), path_src);
+ ret = SESH_ERR_SOME_FILES;
+ continue;
+ }
+
+ /* sudo_check_temp_file() filled in sb for us. */
+ len_src = sb.st_size;
+ if (fstat(fd_dst, &sb) != 0) {
+ sudo_warn("%s", path_dst);
+ sudo_warnx(U_("contents of edit session left in %s"), path_src);
+ ret = SESH_ERR_SOME_FILES;
+ continue;
+ }
+ len_dst = sb.st_size;
+
+ if (sudo_copy_file(path_src, fd_src, len_src, path_dst, fd_dst,
+ len_dst) == -1) {
+ sudo_warnx(U_("contents of edit session left in %s"), path_src);
+ ret = SESH_ERR_SOME_FILES;
+ continue;
+ }
+ unlink(path_src);
+ }
+ if (fd_src != -1)
+ close(fd_src);
+ if (fd_dst != -1)
+ close(fd_dst);
+
+ debug_return_int(ret);
+}
+
+static int
+sesh_sudoedit(enum sesh_mode mode, int flags, char *user,
+ int argc, char *argv[])
+{
+ struct sudo_cred user_cred, run_cred;
+ int ret;
+ debug_decl(sesh_sudoedit, SUDO_DEBUG_EDIT);
+
+ memset(&user_cred, 0, sizeof(user_cred));
+ memset(&run_cred, 0, sizeof(run_cred));
+
+ /* Parse user for -w option, "uid:gid:gid1,gid2,..." */
+ if (user != NULL && !parse_user(user, &user_cred))
+ debug_return_int(SESH_ERR_FAILURE);
+
+ /* No files specified, nothing to do. */
+ if (argc == 0)
+ debug_return_int(SESH_SUCCESS);
+
+ /* Odd number of paths specified. */
+ if (argc & 1)
+ debug_return_int(SESH_ERR_BAD_PATHS);
+
+ /* Masquerade as sudoedit so the user gets consistent error messages. */
+ setprogname("sudoedit");
+
+ /*
+ * sudoedit runs us with the effective user-ID and group-ID of
+ * the target user as well as with the target user's group list.
+ */
+ run_cred.uid = run_cred.euid = geteuid();
+ run_cred.gid = run_cred.egid = getegid();
+ run_cred.ngroups = getgroups(0, NULL); // -V575
+ if (run_cred.ngroups > 0) {
+ run_cred.groups = reallocarray(NULL, run_cred.ngroups,
+ sizeof(GETGROUPS_T));
+ if (run_cred.groups == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__,
+ U_("unable to allocate memory"));
+ debug_return_int(SESH_ERR_FAILURE);
+ }
+ run_cred.ngroups = getgroups(run_cred.ngroups, run_cred.groups);
+ if (run_cred.ngroups < 0) {
+ sudo_warn("%s", U_("unable to get group list"));
+ free(run_cred.groups);
+ debug_return_int(SESH_ERR_FAILURE);
+ }
+ } else {
+ run_cred.ngroups = 0;
+ run_cred.groups = NULL;
+ }
+
+ ret = mode == SESH_EDIT_CREATE ?
+ sesh_edit_create_tfiles(flags, &user_cred, &run_cred, argc, argv) :
+ sesh_edit_copy_tfiles(flags, &user_cred, &run_cred, argc, argv);
+ debug_return_int(ret);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 08:55:07 +0000