+#include "net.h"
+#include "node.h"
+#include "protocol.h"
+
+char *hosts_dir = NULL;
+recvdata_cb_t recv_callback;
+static char *name = NULL;
+char *tinc_conf = NULL;
+static bool tty = false;
+
+#ifdef HAVE_MLOCKALL
+/* If nonzero, disable swapping for this process. */
+static bool do_mlock = false;
+#endif
+
+/* Open a file with the desired permissions, minus the umask.
+ Also, if we want to create an executable file, we call fchmod()
+ to set the executable bits. */
+
+FILE *fopenmask(const char *filename, const char *mode, mode_t perms) {
+ mode_t mask = umask(0);
+ perms &= ~mask;
+ umask(~perms);
+ FILE *f = fopen(filename, mode);
+#ifdef HAVE_FCHMOD
+ if((perms & 0444) && f)
+ fchmod(fileno(f), perms);
+#endif
+ umask(mask);
+ return f;
+}
+
+static void disable_old_keys(const char *filename, const char *what) {
+ char tmpfile[PATH_MAX] = "";
+ char buf[1024];
+ bool disabled = false;
+ bool block = false;
+ bool error = false;
+ FILE *r, *w;
+
+ r = fopen(filename, "r");
+ if(!r)
+ return;
+
+ snprintf(tmpfile, sizeof tmpfile, "%s.tmp", filename);
+
+ struct stat st = {.st_mode = 0600};
+ fstat(fileno(r), &st);
+ w = fopenmask(tmpfile, "w", st.st_mode);
+
+ 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"))) {
+ disabled = true;
+ block = true;
+ }
+ }
+
+ bool ecdsapubkey = !strncasecmp(buf, "ECDSAPublicKey", 14) && strchr(" \t=", buf[14]) && strstr(what, "ECDSA");
+
+ if(ecdsapubkey)
+ disabled = true;
+
+ if(w) {
+ if(block || ecdsapubkey)
+ fputc('#', w);
+ if(fputs(buf, w) < 0) {
+ error = true;
+ break;
+ }
+ }
+
+ if(block && !strncmp(buf, "-----END ", 9))
+ block = false;
+ }
+
+ if(w)
+ if(fclose(w) < 0)
+ error = true;
+ if(ferror(r) || fclose(r) < 0)
+ error = true;
+
+ if(disabled) {
+ if(!w || error) {
+ fprintf(stderr, "Warning: old key(s) found, remove them by hand!\n");
+ if(w)
+ unlink(tmpfile);
+ return;
+ }
+
+#ifdef HAVE_MINGW
+ // We cannot atomically replace files on Windows.
+ char bakfile[PATH_MAX] = "";
+ snprintf(bakfile, sizeof bakfile, "%s.bak", filename);
+ if(rename(filename, bakfile) || rename(tmpfile, filename)) {
+ rename(bakfile, filename);
+#else
+ if(rename(tmpfile, filename)) {
+#endif
+ fprintf(stderr, "Warning: old key(s) found, remove them by hand!\n");
+ } else {
+#ifdef HAVE_MINGW
+ unlink(bakfile);
+#endif
+ fprintf(stderr, "Warning: old key(s) found and disabled.\n");
+ }
+ }
+
+ unlink(tmpfile);
+}
+
+static FILE *ask_and_open(const char *filename, const char *what, const char *mode, bool ask, mode_t perms) {
+ FILE *r;
+ char *directory;
+ char buf[PATH_MAX];
+ char buf2[PATH_MAX];
+
+ /* Check stdin and stdout */
+ if(ask && tty) {
+ /* Ask for a file and/or directory name. */
+ fprintf(stderr, "Please enter a file to save %s to [%s]: ", what, filename);
+
+ if(fgets(buf, sizeof buf, stdin) == NULL) {
+ fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
+ return NULL;
+ }
+
+ size_t len = strlen(buf);
+ if(len)
+ buf[--len] = 0;
+
+ if(len)
+ filename = buf;
+ }
+
+#ifdef HAVE_MINGW
+ if(filename[0] != '\\' && filename[0] != '/' && !strchr(filename, ':')) {
+#else
+ if(filename[0] != '/') {
+#endif
+ /* The directory is a relative path or a filename. */
+ directory = get_current_dir_name();
+ snprintf(buf2, sizeof buf2, "%s" SLASH "%s", directory, filename);
+ filename = buf2;
+ }
+
+ disable_old_keys(filename, what);
+
+ /* Open it first to keep the inode busy */
+
+ r = fopenmask(filename, mode, perms);
+
+ if(!r) {
+ fprintf(stderr, "Error opening file `%s': %s\n", filename, strerror(errno));
+ return NULL;
+ }
+
+ return r;
+}
+
+/*
+ Generate a public/private ECDSA keypair, and ask for a file to store
+ them in.
+*/
+bool ecdsa_keygen(bool ask) {
+ ecdsa_t *key;
+ FILE *f;
+ char *pubname, *privname;
+
+ fprintf(stderr, "Generating ECDSA keypair:\n");
+
+ if(!(key = ecdsa_generate())) {
+ fprintf(stderr, "Error during key generation!\n");
+ return false;
+ } else
+ fprintf(stderr, "Done.\n");
+
+ xasprintf(&privname, "%s" SLASH "ecdsa_key.priv", confbase);
+ f = ask_and_open(privname, "private ECDSA key", "a", ask, 0600);
+ free(privname);
+
+ if(!f)
+ return false;
+
+ if(!ecdsa_write_pem_private_key(key, f)) {
+ fprintf(stderr, "Error writing private key!\n");
+ ecdsa_free(key);
+ fclose(f);
+ return false;
+ }
+
+ fclose(f);
+
+ if(name)
+ xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
+ else
+ xasprintf(&pubname, "%s" SLASH "ecdsa_key.pub", confbase);
+
+ f = ask_and_open(pubname, "public ECDSA key", "a", ask, 0666);
+ free(pubname);
+
+ if(!f)
+ return false;
+
+ char *pubkey = ecdsa_get_base64_public_key(key);
+ fprintf(f, "ECDSAPublicKey = %s\n", pubkey);
+ free(pubkey);
+
+ fclose(f);
+ ecdsa_free(key);
+
+ return true;
+}
+
+static bool try_bind(int port) {
+ struct addrinfo *ai = NULL;
+ struct addrinfo hint = {
+ .ai_flags = AI_PASSIVE,
+ .ai_family = AF_UNSPEC,
+ .ai_socktype = SOCK_STREAM,
+ .ai_protocol = IPPROTO_TCP,
+ };
+
+ char portstr[16];
+ snprintf(portstr, sizeof portstr, "%d", port);
+
+ if(getaddrinfo(NULL, portstr, &hint, &ai) || !ai)
+ return false;
+
+ while(ai) {
+ int fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+ if(!fd)
+ return false;
+ int result = bind(fd, ai->ai_addr, ai->ai_addrlen);
+ closesocket(fd);
+ if(result)
+ return false;
+ ai = ai->ai_next;
+ }