Replace asprintf() by xasprintf().
[tinc] / src / tincd.c
index f909d9a..a13e266 100644 (file)
 
 #include LZO1X_H
 
+#ifndef HAVE_MINGW
+#include <pwd.h>
+#include <grp.h>
+#include <time.h>
+#endif
+
 #include <getopt.h>
 #include "pidfile.h"
 
@@ -73,6 +79,12 @@ bool bypass_security = false;
 /* If nonzero, disable swapping for this process. */
 bool do_mlock = false;
 
+/* If nonzero, chroot to netdir after startup. */
+static bool do_chroot = false;
+
+/* If !NULL, do setuid to given user after startup */
+static const char *switchuser = NULL;
+
 /* If nonzero, write log entries to a separate file. */
 bool use_logfile = false;
 
@@ -94,6 +106,8 @@ static struct option const long_options[] = {
        {"debug", optional_argument, NULL, 'd'},
        {"bypass-security", no_argument, NULL, 3},
        {"mlock", no_argument, NULL, 'L'},
+       {"chroot", no_argument, NULL, 'R'},
+       {"user", required_argument, NULL, 'U'},
        {"logfile", optional_argument, NULL, 4},
        {"pidfile", required_argument, NULL, 5},
        {NULL, 0, NULL, 0}
@@ -119,6 +133,8 @@ static void usage(bool status)
                                "  -L, --mlock                Lock tinc into main memory.\n"
                                "      --logfile[=FILENAME]   Write log entries to a logfile.\n"
                                "      --pidfile=FILENAME     Write PID to FILENAME.\n"
+                               "  -R, --chroot               chroot to NET dir at startup.\n"
+                               "  -U, --user=USER            setuid to given USER at startup.\n"
                                "      --help                 Display this help and exit.\n"
                                "      --version              Output version information and exit.\n\n"));
                printf(_("Report bugs to tinc@tinc-vpn.org.\n"));
@@ -130,7 +146,7 @@ static bool parse_options(int argc, char **argv)
        int r;
        int option_index = 0;
 
-       while((r = getopt_long(argc, argv, "c:DLd::k::n:K::", long_options, &option_index)) != EOF) {
+       while((r = getopt_long(argc, argv, "c:DLd::k::n:K::RU:", long_options, &option_index)) != EOF) {
                switch (r) {
                        case 0:                         /* long option */
                                break;
@@ -144,8 +160,13 @@ static bool parse_options(int argc, char **argv)
                                break;
 
                        case 'L':                               /* no detach */
+#ifndef HAVE_MLOCKALL
+                               logger(LOG_ERR, _("%s not supported on this platform"), "mlockall()");
+                               return false;
+#else
                                do_mlock = true;
                                break;
+#endif
 
                        case 'd':                               /* inc debug level */
                                if(optarg)
@@ -210,6 +231,14 @@ static bool parse_options(int argc, char **argv)
                                        generate_keys = 1024;
                                break;
 
+                       case 'R':                               /* chroot to NETNAME dir */
+                               do_chroot = true;
+                               break;
+
+                       case 'U':                               /* setuid to USER */
+                               switchuser = optarg;
+                               break;
+
                        case 1:                                 /* show help */
                                show_help = true;
                                break;
@@ -308,7 +337,7 @@ static bool keygen(int bits)
        } else
                fprintf(stderr, _("Done.\n"));
 
-       asprintf(&filename, "%s/rsa_key.priv", confbase);
+       xasprintf(&filename, "%s/rsa_key.priv", confbase);
        f = ask_and_open(filename, _("private RSA key"));
 
        if(!f)
@@ -327,9 +356,9 @@ static bool keygen(int bits)
        free(filename);
 
        if(name)
-               asprintf(&filename, "%s/hosts/%s", confbase, name);
+               xasprintf(&filename, "%s/hosts/%s", confbase, name);
        else
-               asprintf(&filename, "%s/rsa_key.pub", confbase);
+               xasprintf(&filename, "%s/rsa_key.pub", confbase);
 
        f = ask_and_open(filename, _("public RSA key"));
 
@@ -360,7 +389,7 @@ static void make_names(void)
 #endif
 
        if(netname)
-               asprintf(&identname, "tinc.%s", netname);
+               xasprintf(&identname, "tinc.%s", netname);
        else
                identname = xstrdup("tinc");
 
@@ -368,12 +397,12 @@ static void make_names(void)
        if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
                if(!RegQueryValueEx(key, NULL, 0, 0, installdir, &len)) {
                        if(!logfilename)
-                               asprintf(&logfilename, "%s/log/%s.log", identname);
+                               xasprintf(&logfilename, "%s/log/%s.log", identname);
                        if(!confbase) {
                                if(netname)
-                                       asprintf(&confbase, "%s/%s", installdir, netname);
+                                       xasprintf(&confbase, "%s/%s", installdir, netname);
                                else
-                                       asprintf(&confbase, "%s", installdir);
+                                       xasprintf(&confbase, "%s", installdir);
                        }
                }
                RegCloseKey(key);
@@ -383,19 +412,19 @@ static void make_names(void)
 #endif
 
        if(!pidfilename)
-               asprintf(&pidfilename, LOCALSTATEDIR "/run/%s.pid", identname);
+               xasprintf(&pidfilename, LOCALSTATEDIR "/run/%s.pid", identname);
 
        if(!logfilename)
-               asprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
+               xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
 
        if(netname) {
                if(!confbase)
-                       asprintf(&confbase, CONFDIR "/tinc/%s", netname);
+                       xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
                else
                        logger(LOG_INFO, _("Both netname and configuration directory given, using the latter..."));
        } else {
                if(!confbase)
-                       asprintf(&confbase, CONFDIR "/tinc");
+                       xasprintf(&confbase, CONFDIR "/tinc");
        }
 }
 
@@ -407,6 +436,63 @@ static void free_names() {
        if (confbase) free(confbase);
 }
 
+static bool drop_privs() {
+#ifdef HAVE_MINGW
+       if (switchuser) {
+               logger(LOG_ERR, _("%s not supported on this platform"), "-U");
+               return false;
+       }
+       if (do_chroot) {
+               logger(LOG_ERR, _("%s not supported on this platform"), "-R");
+               return false;
+       }
+#else
+       uid_t uid = 0;
+       if (switchuser) {
+               struct passwd *pw = getpwnam(switchuser);
+               if (!pw) {
+                       logger(LOG_ERR, _("unknown user `%s'"), switchuser);
+                       return false;
+               }
+               uid = pw->pw_uid;
+               if (initgroups(switchuser, pw->pw_gid) != 0 ||
+                   setgid(pw->pw_gid) != 0) {
+                       logger(LOG_ERR, _("System call `%s' failed: %s"),
+                              "initgroups", strerror(errno));
+                       return false;
+               }
+               endgrent();
+               endpwent();
+       }
+       if (do_chroot) {
+               tzset();        /* for proper timestamps in logs */
+               if (chroot(confbase) != 0 || chdir("/") != 0) {
+                       logger(LOG_ERR, _("System call `%s' failed: %s"),
+                              "chroot", strerror(errno));
+                       return false;
+               }
+               free(confbase);
+               confbase = xstrdup("");
+       }
+       if (switchuser)
+               if (setuid(uid) != 0) {
+                       logger(LOG_ERR, _("System call `%s' failed: %s"),
+                              "setuid", strerror(errno));
+                       return false;
+               }
+#endif
+       return true;
+}
+
+#ifdef HAVE_MINGW
+# define setpriority(level) SetPriorityClass(GetCurrentProcess(), level)
+#else
+# define NORMAL_PRIORITY_CLASS 0
+# define BELOW_NORMAL_PRIORITY_CLASS 10
+# define HIGH_PRIORITY_CLASS -10
+# define setpriority(level) nice(level)
+#endif
+
 int main(int argc, char **argv)
 {
        program_name = argv[0];
@@ -442,20 +528,6 @@ int main(int argc, char **argv)
 
        openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
 
-       /* Lock all pages into memory if requested */
-
-       if(do_mlock)
-#ifdef HAVE_MLOCKALL
-               if(mlockall(MCL_CURRENT | MCL_FUTURE)) {
-                       logger(LOG_ERR, _("System call `%s' failed: %s"), "mlockall",
-                                  strerror(errno));
-#else
-       {
-               logger(LOG_ERR, _("mlockall() not supported on this platform!"));
-#endif
-               return -1;
-       }
-
        g_argv = argv;
 
        init_configuration(&config_tree);
@@ -500,11 +572,46 @@ int main2(int argc, char **argv)
 
        if(!detach())
                return 1;
-               
+
+#ifdef HAVE_MLOCKALL
+       /* Lock all pages into memory if requested.
+        * This has to be done after daemon()/fork() so it works for child.
+        * No need to do that in parent as it's very short-lived. */
+       if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
+               logger(LOG_ERR, _("System call `%s' failed: %s"), "mlockall",
+                  strerror(errno));
+               return 1;
+       }
+#endif
 
        /* Setup sockets and open device. */
 
-       if(!setup_network_connections())
+       if(!setup_network())
+               goto end;
+
+       /* Initiate all outgoing connections. */
+
+       try_outgoing_connections();
+
+       /* Change process priority */
+
+        char *priority = 0;
+
+        if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
+                if(!strcasecmp(priority, "Normal"))
+                        setpriority(NORMAL_PRIORITY_CLASS);
+                else if(!strcasecmp(priority, "Low"))
+                        setpriority(BELOW_NORMAL_PRIORITY_CLASS);
+                else if(!strcasecmp(priority, "High"))
+                        setpriority(HIGH_PRIORITY_CLASS);
+                else {
+                        logger(LOG_ERR, _("Invalid priority `%s`!"), priority);
+                        goto end;
+                }
+        }
+
+       /* drop privileges */
+       if (!drop_privs())
                goto end;
 
        /* Start main loop. It only exits when tinc is killed. */
@@ -533,6 +640,6 @@ end:
 
        exit_configuration(&config_tree);
        free_names();
-       
+
        return status;
 }