Allocate temporary filenames on the stack.

[tinc] / src / tincctl.c

diff --git a/src/tincctl.c b/src/tincctl.c
index e0a6086..fc59c58 100644 (file)
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -376,7 +376,7 @@ static FILE *ask_and_open(const char *filename, const char *what, const char *mo
 static bool ed25519_keygen(bool ask) {
        ecdsa_t *key;
        FILE *f;
-       char *pubname, *privname;
+       char fname[PATH_MAX];
 
        fprintf(stderr, "Generating Ed25519 keypair:\n");
 
@@ -386,41 +386,42 @@ static bool ed25519_keygen(bool ask) {
        } else
                fprintf(stderr, "Done.\n");
 
-       xasprintf(&privname, "%s" SLASH "ed25519_key.priv", confbase);
-       f = ask_and_open(privname, "private Ed25519 key", "a", ask, 0600);
-       free(privname);
+       snprintf(fname, sizeof fname, "%s" SLASH "ed25519_key.priv", confbase);
+       f = ask_and_open(fname, "private Ed25519 key", "a", ask, 0600);
 
        if(!f)
-               return false;
+               goto error;
 
        if(!ecdsa_write_pem_private_key(key, f)) {
                fprintf(stderr, "Error writing private key!\n");
-               ecdsa_free(key);
-               fclose(f);
-               return false;
+               goto error;
        }
 
        fclose(f);
 
        if(name)
-               xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
+               snprintf(fname, sizeof fname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
        else
-               xasprintf(&pubname, "%s" SLASH "ed25519_key.pub", confbase);
+               snprintf(fname, sizeof fname, "%s" SLASH "ed25519_key.pub", confbase);
 
-       f = ask_and_open(pubname, "public Ed25519 key", "a", ask, 0666);
-       free(pubname);
+       f = ask_and_open(fname, "public Ed25519 key", "a", ask, 0666);
 
        if(!f)
                return false;
 
        char *pubkey = ecdsa_get_base64_public_key(key);
        fprintf(f, "Ed25519PublicKey = %s\n", pubkey);
-       free(pubkey);
 
        fclose(f);
        ecdsa_free(key);
 
        return true;
+
+error:
+       if(f)
+               fclose(f);
+       ecdsa_free(key);
+       return false;
 }
 
 #ifndef DISABLE_LEGACY
@@ -431,7 +432,7 @@ static bool ed25519_keygen(bool ask) {
 static bool rsa_keygen(int bits, bool ask) {
        rsa_t *key;
        FILE *f;
-       char *pubname, *privname;
+       char fname[PATH_MAX];
 
        // Make sure the key size is a multiple of 8 bits.
        bits &= ~0x7;
@@ -450,44 +451,44 @@ static bool rsa_keygen(int bits, bool ask) {
        } else
                fprintf(stderr, "Done.\n");
 
-       xasprintf(&privname, "%s" SLASH "rsa_key.priv", confbase);
-       f = ask_and_open(privname, "private RSA key", "a", ask, 0600);
-       free(privname);
+       snprintf(fname, sizeof fname, "%s" SLASH "rsa_key.priv", confbase);
+       f = ask_and_open(fname, "private RSA key", "a", ask, 0600);
 
        if(!f)
-               return false;
+               goto error;
 
        if(!rsa_write_pem_private_key(key, f)) {
                fprintf(stderr, "Error writing private key!\n");
-               fclose(f);
-               rsa_free(key);
-               return false;
+               goto error;
        }
 
        fclose(f);
 
        if(name)
-               xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
+               snprintf(fname, sizeof fname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
        else
-               xasprintf(&pubname, "%s" SLASH "rsa_key.pub", confbase);
+               snprintf(fname, sizeof fname, "%s" SLASH "rsa_key.pub", confbase);
 
-       f = ask_and_open(pubname, "public RSA key", "a", ask, 0666);
-       free(pubname);
+       f = ask_and_open(fname, "public RSA key", "a", ask, 0666);
 
        if(!f)
-               return false;
+               goto error;
 
        if(!rsa_write_pem_public_key(key, f)) {
                fprintf(stderr, "Error writing public key!\n");
-               fclose(f);
-               rsa_free(key);
-               return false;
+               goto error;
        }
 
        fclose(f);
        rsa_free(key);
 
        return true;
+
+error:
+       if(f)
+               fclose(f);
+       rsa_free(key);
+       return false;
 }
 #endif
 
@@ -1597,11 +1598,11 @@ static int cmd_config(int argc, char *argv[]) {
        }
 
        // Open the right configuration file.
-       char *filename;
+       char filename[PATH_MAX];
        if(node)
-               xasprintf(&filename, "%s" SLASH "%s", hosts_dir, node);
+               snprintf(filename, sizeof filename, "%s" SLASH "%s", hosts_dir, node);
        else
-               filename = tinc_conf;
+               snprintf(filename, sizeof filename, "%s", tinc_conf);
 
        FILE *f = fopen(filename, "r");
        if(!f) {
@@ -1609,11 +1610,11 @@ static int cmd_config(int argc, char *argv[]) {
                return 1;
        }
 
-       char *tmpfile = NULL;
+       char tmpfile[PATH_MAX];
        FILE *tf = NULL;
 
        if(action >= -1) {
-               xasprintf(&tmpfile, "%s.config.tmp", filename);
+               snprintf(tmpfile, sizeof tmpfile, "%s.config.tmp", filename);
                tf = fopen(tmpfile, "w");
                if(!tf) {
                        fprintf(stderr, "Could not open temporary file %s: %s\n", tmpfile, strerror(errno));
@@ -1799,11 +1800,11 @@ int check_port(char *name) {
        for(int i = 0; i < 100; i++) {
                int port = 0x1000 + (rand() & 0x7fff);
                if(try_bind(port)) {
-                       char *filename;
-                       xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, name);
+                       char filename[PATH_MAX];
+                       snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", confbase, name);
                        FILE *f = fopen(filename, "a");
-                       free(filename);
                        if(!f) {
+                               fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
                                fprintf(stderr, "Please change tinc's Port manually.\n");
                                return 0;
                        }
@@ -1894,8 +1895,8 @@ static int cmd_init(int argc, char *argv[]) {
        check_port(name);
 
 #ifndef HAVE_MINGW
-       char *filename;
-       xasprintf(&filename, "%s" SLASH "tinc-up", confbase);
+       char filename[PATH_MAX];
+       snprintf(filename, sizeof filename, "%s" SLASH "tinc-up", confbase);
        if(access(filename, F_OK)) {
                FILE *f = fopenmask(filename, "w", 0777);
                if(!f) {
@@ -2005,12 +2006,12 @@ static int cmd_edit(int argc, char *argv[]) {
                return 1;
        }
 
-       char *filename = NULL;
+       char filename[PATH_MAX] = "";
 
        if(strncmp(argv[1], "hosts" SLASH, 6)) {
                for(int i = 0; conffiles[i]; i++) {
                        if(!strcmp(argv[1], conffiles[i])) {
-                               xasprintf(&filename, "%s" SLASH "%s", confbase, argv[1]);
+                               snprintf(filename, sizeof filename, "%s" SLASH "%s", confbase, argv[1]);
                                break;
                        }
                }
@@ -2018,8 +2019,8 @@ static int cmd_edit(int argc, char *argv[]) {
                argv[1] += 6;
        }
 
-       if(!filename) {
-               xasprintf(&filename, "%s" SLASH "%s", hosts_dir, argv[1]);
+       if(!*filename) {
+               snprintf(filename, sizeof filename, "%s" SLASH "%s", hosts_dir, argv[1]);
                char *dash = strchr(argv[1], '-');
                if(dash) {
                        *dash++ = 0;
@@ -2037,6 +2038,7 @@ static int cmd_edit(int argc, char *argv[]) {
        xasprintf(&command, "edit \"%s\"", filename);
 #endif
        int result = system(command);
+       free(command);
        if(result)
                return result;
 
@@ -2048,8 +2050,8 @@ static int cmd_edit(int argc, char *argv[]) {
 }
 
 static int export(const char *name, FILE *out) {
-       char *filename;
-       xasprintf(&filename, "%s" SLASH "%s", hosts_dir, name);
+       char filename[PATH_MAX];
+       snprintf(filename, sizeof filename, "%s" SLASH "%s", hosts_dir, name);
        FILE *in = fopen(filename, "r");
        if(!in) {
                fprintf(stderr, "Could not open configuration file %s: %s\n", filename, strerror(errno));
@@ -2136,7 +2138,7 @@ static int cmd_import(int argc, char *argv[]) {
 
        char buf[4096];
        char name[4096];
-       char *filename = NULL;
+       char filename[PATH_MAX] = "";
        int count = 0;
        bool firstline = true;
 
@@ -2152,8 +2154,7 @@ static int cmd_import(int argc, char *argv[]) {
                        if(out)
                                fclose(out);
 
-                       free(filename);
-                       xasprintf(&filename, "%s" SLASH "%s", hosts_dir, name);
+                       snprintf(filename, sizeof filename, "%s" SLASH "%s", hosts_dir, name);
 
                        if(!force && !access(filename, F_OK)) {
                                fprintf(stderr, "Host configuration file %s already exists, skipping.\n", filename);
@@ -2259,11 +2260,10 @@ static int cmd_network(int argc, char *argv[]) {
                        continue;
                }
 
-               char *fname;
-               xasprintf(&fname, "%s/%s/tinc.conf", confdir, ent->d_name);
+               char fname[PATH_MAX];
+               snprintf(fname, sizeof fname, "%s/%s/tinc.conf", confdir, ent->d_name);
                if(!access(fname, R_OK))
                        printf("%s\n", ent->d_name);
-               free(fname);
        }
 
        closedir(dir);