Add RCS ID.

[opendoas.git] / doas.c

diff --git a/doas.c b/doas.c
index 1e1fb530f737c28845080ac31554498734c6efb9..02cc4b2a84339c81804d6aec634c840c9b2ba43b 100644 (file)
--- a/doas.c
+++ b/doas.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: doas.c,v 1.2 2015/07/16 21:00:59 tedu Exp $ */
+/* $OpenBSD: doas.c,v 1.7 2015/07/18 00:19:38 doug Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -14,7 +14,9 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+
 #include <sys/types.h>
+#include <sys/stat.h>
 
 #include <limits.h>
 #include <login_cap.h>
@@ -33,7 +35,7 @@
 static void __dead
 usage(void)
 {
-       fprintf(stderr, "usage: doas [-u user] command [args]\n");
+       fprintf(stderr, "usage: doas [-s] [-u user] command [args]\n");
        exit(1);
 }
 
@@ -139,18 +141,28 @@ parseconfig(const char *filename)
 {
        extern FILE *yyfp;
        extern int yyparse(void);
+       struct stat sb;
 
        yyfp = fopen(filename, "r");
        if (!yyfp) {
                fprintf(stderr, "doas is not enabled.\n");
                exit(1);
        }
+
+       if (fstat(fileno(yyfp), &sb) != 0)
+               err(1, "fstat(\"%s\")", filename);
+       if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0)
+               errx(1, "%s is writable by group or other", filename);
+       if (sb.st_uid != 0)
+               errx(1, "%s is not owned by root", filename);
+
        yyparse();
        fclose(yyfp);
 }
 
 static int
-copyenvhelper(const char **oldenvp, const char **safeset, int nsafe, char **envp, int ei)
+copyenvhelper(const char **oldenvp, const char **safeset, int nsafe,
+    char **envp, int ei)
 {
        int i;
        for (i = 0; i < nsafe; i++) {
@@ -187,6 +199,8 @@ copyenv(const char **oldenvp, struct rule *rule)
        if ((rule->options & KEEPENV) && !rule->envlist) {
                j = arraylen(oldenvp);
                envp = reallocarray(NULL, j + 1, sizeof(char *));
+               if (!envp)
+                       err(1, "reallocarray");
                for (i = 0; i < j; i++) {
                        if (!(envp[i] = strdup(oldenvp[i])))
                                err(1, "strdup");
@@ -230,8 +244,8 @@ fail(void)
 int
 main(int argc, char **argv, char **envp)
 {
-       char cmdline[1024];
-       char myname[32];
+       char cmdline[LINE_MAX];
+       char myname[_PW_NAME_LEN + 1];
        uid_t uid, target = 0;
        gid_t groups[NGROUPS_MAX + 1];
        int ngroups;
@@ -239,16 +253,23 @@ main(int argc, char **argv, char **envp)
        struct rule *rule;
        const char *cmd;
        int i, ch;
-       const char *safepath = "/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin";
+       const char *safepath = "/bin:/sbin:/usr/bin:/usr/sbin:"
+           "/usr/local/bin:/usr/local/sbin";
+       int sflag = 0;
+       char *shargv[] = { NULL, NULL };
+       char *sh;
 
        parseconfig("/etc/doas.conf");
 
-       while ((ch = getopt(argc, argv, "u:")) != -1) {
+       while ((ch = getopt(argc, argv, "su:")) != -1) {
                switch (ch) {
                case 'u':
                        if (parseuid(optarg, &target) != 0)
                                errx(1, "unknown user");
                        break;
+               case 's':
+                       sflag = 1;
+                       break;
                default:
                        usage();
                        break;
@@ -257,34 +278,50 @@ main(int argc, char **argv, char **envp)
        argv += optind;
        argc -= optind;
 
-       if (!argc)
+       if ((!sflag && !argc) || (sflag && argc))
                usage();
 
-       cmd = argv[0];
-       strlcpy(cmdline, argv[0], sizeof(cmdline));
-       for (i = 1; i < argc; i++) {
-               strlcat(cmdline, " ", sizeof(cmdline));
-               strlcat(cmdline, argv[i], sizeof(cmdline));
-       }
-
        uid = getuid();
        pw = getpwuid(uid);
        if (!pw)
                err(1, "getpwuid failed");
-       strlcpy(myname, pw->pw_name, sizeof(myname));
+       if (strlcpy(myname, pw->pw_name, sizeof(myname)) >= sizeof(myname))
+               errx(1, "pw_name too long");
        ngroups = getgroups(NGROUPS_MAX, groups);
        if (ngroups == -1)
                err(1, "can't get groups");
        groups[ngroups++] = getgid();
 
+       if (sflag) {
+               sh = getenv("SHELL");
+               if (sh == NULL || *sh == '\0')
+                       shargv[0] = pw->pw_shell;
+               else
+                       shargv[0] = sh;
+               argv = shargv;
+               argc = 1;
+       }
+
+       cmd = argv[0];
+       if (strlcpy(cmdline, argv[0], sizeof(cmdline)) >= sizeof(cmdline))
+               errx(1, "command line too long");
+       for (i = 1; i < argc; i++) {
+               if (strlcat(cmdline, " ", sizeof(cmdline)) >= sizeof(cmdline))
+                       errx(1, "command line too long");
+               if (strlcat(cmdline, argv[i], sizeof(cmdline)) >= sizeof(cmdline))
+                       errx(1, "command line too long");
+       }
+
        if (!permit(uid, groups, ngroups, &rule, target, cmd)) {
-               syslog(LOG_AUTHPRIV | LOG_NOTICE, "failed command for %s: %s", myname, cmdline);
+               syslog(LOG_AUTHPRIV | LOG_NOTICE,
+                   "failed command for %s: %s", myname, cmdline);
                fail();
        }
 
        if (!(rule->options & NOPASS)) {
                if (!auth_userokay(myname, NULL, NULL, NULL)) {
-                       syslog(LOG_AUTHPRIV | LOG_NOTICE, "failed password for %s", myname);
+                       syslog(LOG_AUTHPRIV | LOG_NOTICE,
+                           "failed password for %s", myname);
                        fail();
                }
        }
@@ -298,8 +335,10 @@ main(int argc, char **argv, char **envp)
            LOGIN_SETUSER) != 0)
                errx(1, "failed to set user context for target");
 
-       syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command as %s: %s", myname, pw->pw_name, cmdline);
-       setenv("PATH", safepath, 1);
+       syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command as %s: %s",
+           myname, pw->pw_name, cmdline);
+       if (setenv("PATH", safepath, 1) == -1)
+               err(1, "failed to set PATH '%s'", safepath);
        execvpe(cmd, argv, envp);
        err(1, "%s", cmd);
 }