Warn when incorrect use of add or set causes variables to be removed.

[tinc] / src / tincctl.c

diff --git a/src/tincctl.c b/src/tincctl.c
index 4349b79..d02bda5 100644 (file)
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -116,7 +116,7 @@ static void usage(bool status) {
                                "  del VARIABLE [VALUE]       Remove VARIABLE [only ones with watching VALUE]\n"
                                "  start [tincd options]      Start tincd.\n"
                                "  stop                       Stop tincd.\n"
-                               "  restart                    Restart tincd.\n"
+                               "  restart [tincd options]    Restart tincd.\n"
                                "  reload                     Partially reload configuration of running tincd.\n"
                                "  pid                        Show PID of currently running tincd.\n"
                                "  generate-keys [bits]       Generate new RSA and ECDSA public/private keypairs.\n"
@@ -227,6 +227,16 @@ static void disable_old_keys(const char *filename, const char *what) {
 
        w = fopen(tmpfile, "w");
 
+#ifdef HAVE_FCHMOD
+       /* Let the temporary file have the same permissions as the original. */
+
+       if(w) {
+               struct stat st = {.st_mode = 0600};
+               fstat(fileno(r), &st);
+               fchmod(fileno(w), st.st_mode);
+       }
+#endif
+
        while(fgets(buf, sizeof buf, r)) {
                if(!block && !strncmp(buf, "-----BEGIN ", 11)) {
                        if((strstr(buf, " EC ") && strstr(what, "ECDSA")) || (strstr(buf, " RSA ") && strstr(what, "RSA"))) {
@@ -324,8 +334,6 @@ static FILE *ask_and_open(const char *filename, const char *what, const char *mo
                filename = buf2;
        }
 
-       umask(0077); /* Disallow everything for group and other */
-
        disable_old_keys(filename, what);
 
        /* Open it first to keep the inode busy */
@@ -871,7 +879,7 @@ static int cmd_stop(int argc, char *argv[]) {
 }
 
 static int cmd_restart(int argc, char *argv[]) {
-       cmd_stop(argc, argv);
+       cmd_stop(1, argv);
        return cmd_start(argc, argv);
 }
 
@@ -1406,6 +1414,7 @@ static int cmd_config(int argc, char *argv[]) {
 
        /* Some simple checks. */
        bool found = false;
+       bool warnonremove = false;
 
        for(int i = 0; variables[i].name; i++) {
                if(strcasecmp(variables[i].name, variable))
@@ -1444,6 +1453,16 @@ static int cmd_config(int argc, char *argv[]) {
                                return 1;
                }
 
+               /* Change "add" into "set" for variables that do not allow multiple occurences.
+                  Turn on warnings when it seems variables might be removed unintentionally. */
+
+               if(action == 1 && !(variables[i].type & VAR_MULTIPLE)) {
+                       warnonremove = true;
+                       action = 0;
+               } else if(action == 0 && (variables[i].type & VAR_MULTIPLE)) {
+                       warnonremove = true;
+               }
+
                break;
        }
 
@@ -1526,9 +1545,14 @@ static int cmd_config(int argc, char *argv[]) {
                                }
                        // Set
                        } else if(action == 0) {
+                               // Warn if "set" was used for variables that can occur multiple times
+                               if(warnonremove && strcasecmp(bvalue, value))
+                                       fprintf(stderr, "Warning: removing %s = %s\n", variable, bvalue);
+
                                // Already set? Delete the rest...
                                if(set)
                                        continue;
+
                                // Otherwise, replace.
                                if(fprintf(tf, "%s = %s\n", variable, value) < 0) {
                                        fprintf(stderr, "Error writing to temporary file %s: %s\n", tmpfile, strerror(errno));
@@ -1702,7 +1726,9 @@ static int cmd_init(int argc, char *argv[]) {
                        fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
                        return 1;
                }
-               fchmod(fileno(f), 0755);
+               mode_t mask = umask(0);
+               umask(mask);
+               fchmod(fileno(f), 0755 & ~mask);
                fprintf(f, "#!/bin/sh\n\necho 'Unconfigured tinc-up script, please edit!'\n\n#ifconfig $INTERFACE <your vpn IP address> netmask <netmask of whole VPN>\n");
                fclose(f);
        }