add support for permanent redirects

dimkr · Apr 21, 2023 · e147e94 · e147e94
1 parent 89e4568
commit e147e94
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Showing 2 changed files with 100 additions and 47 deletions.
diff --git a/README.md b/README.md
@@ -17,6 +17,7 @@ gplaces is originally a Gemini port of the [delve](https://github.com/kieselstei
 - variables
 - ~command aliases~ use variables
 - sh-style history with $XDG_DATA_HOME/gplaces_history or ~/.gplaces_history
+- permanent redirects with $XDG_DATA_HOME/gplaces_redirects or ~/.gplaces_redirects
 - VT100 compatible with ANSI escape sequences
 	- with [NO_COLOR](https://no-color.org/) support
 - no exotic external dependencies, no NIH
@@ -115,4 +116,4 @@ additional documentation and more details are available in `man gplaces`. type `
 ## Statistic
 Language|files|blank|comment|code
 :-------|-------:|-------:|-------:|-------:
-C|1|256|60|1153
+C|1|267|61|1193
diff --git a/gplaces.c b/gplaces.c
@@ -170,6 +170,39 @@ static int get_var_integer(const char *name, int def) {
 }
 
 
+/*============================================================================*/
+static void *map_file(const char *name, int *fd, size_t *size) {
+	static char path[1024];
+	struct stat stbuf;
+	const char *home;
+	void *p;
+
+	if ((home = getenv("XDG_DATA_HOME")) != NULL) snprintf(path, sizeof(path), "%s/gplaces_%s", home, name);
+	else if ((home = getenv("HOME")) != NULL) snprintf(path, sizeof(path), "%s/.gplaces_%s", home, name);
+	else return NULL;
+
+	if ((*fd = open(path, O_RDWR | O_CREAT | O_APPEND, 0600)) == -1) return NULL;
+	if (fstat(*fd, &stbuf) == -1) { close(*fd); return NULL; }
+	if ((*size = (size_t)stbuf.st_size) == 0) return NULL;
+	if ((p = mmap(NULL, stbuf.st_size % SIZE_MAX, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0)) == MAP_FAILED) { close(*fd); return NULL; }
+	return p;
+}
+
+
+__attribute__((format(printf, 2, 3)))
+static int append_line(int fd, const char *fmt, ...) {
+	va_list va;
+	FILE *fp;
+	int ret;
+	if ((fp = fdopen(fd, "a")) == NULL) return 0;
+	va_start(va, fmt);
+	ret = vfprintf(fp, fmt, va) > 0;
+	va_end(va);
+	fclose(fp);
+	return ret;
+}
+
+
 /*============================================================================*/
 static Selector *new_selector(const char type) {
 	Selector *new = calloc(1, sizeof(Selector));
@@ -253,6 +286,42 @@ static int parse_url(Selector *sel, const char *from, const char *input) {
 }
 
 
+static int redirect(Selector *sel, const char *to, size_t len) {
+	char *from = sel->url; sel->url = NULL;
+	curl_free(sel->scheme); sel->scheme = NULL;
+	curl_free(sel->host); sel->host = NULL;
+	if (sel->port != defport) { curl_free(sel->port); }; sel->port = NULL;
+	curl_free(sel->path); sel->path = NULL;
+	curl_url_cleanup(sel->cu); sel->cu = NULL;
+	free(sel->rawurl); if ((sel->rawurl = len > 0 ? strndup(to, len) : strdup(to)) == NULL) error(1, "cannot allocate new string");
+	if (!parse_url(sel, from, NULL)) { curl_free(from); return 0; }
+	curl_free(from);
+	fprintf(stderr, "redirected to `%s`\n", sel->url);
+	return 1;
+}
+
+
+static int perm_redirect(Selector *sel, const char *to) {
+	size_t size = 1, len;
+	const char *p, *start, *end;
+	int fd, ret = 20, found = 0;
+
+	len = strlen(sel->url);
+
+	if ((p = map_file("redirs", &fd, &size)) == NULL && size > 0) return 40;
+	else if (p != NULL) {
+		for (end = p; !found && (start = memmem(end, size - (end - p), sel->url, len)) != NULL; end = start + len + 1) {
+			if (!(found = ((start == p || *(start - 1) == '\n') && size - (start - p) >= len + 2 && start[len] == ' ' && start[len + 1] != '\n'))) continue;
+			ret = redirect(sel, &start[len + 1], strcspn(&start[len + 1], " \n")) ? 31 : 40;
+		}
+		munmap((void *)p, size);
+	}
+	if (to != NULL && !found) ret = (append_line(fd, "%s %s\n", sel->url, to) && redirect(sel, to, -1)) ? 31 : 40;
+	close(fd);
+	return ret;
+}
+
+
 static Selector *find_selector(SelectorList *list, int index) {
 	Selector *sel;
 	long i = 0;
@@ -567,15 +636,13 @@ static void print_gemtext(FILE *fp, SelectorList *list, const char *filter) {
 
 /*============================================================================*/
 static int tofu(X509 *cert, const char *host, int ask) {
-	static char hosts[1024], buffer[1024], hex[EVP_MAX_MD_SIZE * 2 + 1];
+	static char buffer[1024], hex[EVP_MAX_MD_SIZE * 2 + 1];
 	static unsigned char md[EVP_MAX_MD_SIZE];
-	struct stat stbuf;
-	size_t hlen;
-	FILE *fp = NULL;
-	const char *home, *end, *p = MAP_FAILED;
-	char *start, *line;
+	size_t size = 1, hlen;
+	const char *p, *end;
+	char *line, *start;
 	unsigned int mdlen, i;
-	int fd, found = 0, trust = 0;
+	int fd = -1, found = 0, trust = 0;
 
 	if (X509_digest(cert, EVP_sha512(), md, &mdlen) == 0) return 0;
 
@@ -587,36 +654,26 @@ static int tofu(X509 *cert, const char *host, int ask) {
 
 	hlen = strlen(host);
 
-	if ((home = getenv("XDG_DATA_HOME")) != NULL) snprintf(hosts, sizeof(hosts), "%s/gplaces_hosts", home);
-	else if ((home = getenv("HOME")) != NULL) snprintf(hosts, sizeof(hosts), "%s/.gplaces_hosts", home);
-	else return 0;
-
-	if ((fd = open(hosts, O_RDWR | O_CREAT | O_APPEND, 0600)) != -1) {
-		if (fstat(fd, &stbuf) == -1) { close(fd); return 0; }
-		if (stbuf.st_size > 0) {
-			if ((p = mmap(NULL, stbuf.st_size % SIZE_MAX, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) { close(fd); return 0; }
-			for (end = (const char *)p; !found && (start = memmem(end, stbuf.st_size - (end - p), host, hlen)) != NULL; end = start + hlen + 1) {
-				if (!(found = ((start == p || *(start - 1) == '\n') && (size_t)stbuf.st_size - (start - p) >= hlen + 2 && start[hlen] == ' ' && start[hlen + 1] != '\n'))) continue;
-				if ((size_t)stbuf.st_size - (start - p) < hlen + 1 + mdlen * 2 + 1 || start[hlen + 1 + mdlen * 2] != '\n') break;
-				if ((trust = memcmp(&start[hlen + 1], hex, mdlen * 2) == 0) || !ask) break;
-				if (color) snprintf(buffer, sizeof(buffer), "\33[35mTrust new certificate for `%s`? (y/n)>\33[0m ", host);
-				else snprintf(buffer, sizeof(buffer), "Trust new certificate for `%s`? (y/n)> ", host);
-				if ((line = bestline(buffer)) != NULL) {
-					if (*line == 'y' || *line == 'Y') {
-						memcpy(&start[hlen + 1], hex, mdlen * 2);
-						trust = 1;
-					}
-					free(line);
+	if ((p = map_file("hosts", &fd, &size)) == NULL && size > 0) return 0;
+	else if (p != NULL) {
+		for (end = p; !found && (start = memmem(end, size - (end - p), host, hlen)) != NULL; end = start + hlen + 1) {
+			if (!(found = ((start == p || *(start - 1) == '\n') && size - (start - p) >= hlen + 2 && start[hlen] == ' ' && start[hlen + 1] != '\n'))) continue;
+			if (size - (start - p) < hlen + 1 + mdlen * 2 + 1 || start[hlen + 1 + mdlen * 2] != '\n') break;
+			if ((trust = memcmp(&start[hlen + 1], hex, mdlen * 2) == 0) || !ask) break;
+			if (color) snprintf(buffer, sizeof(buffer), "\33[35mTrust new certificate for `%s`? (y/n)>\33[0m ", host);
+			else snprintf(buffer, sizeof(buffer), "Trust new certificate for `%s`? (y/n)> ", host);
+			if ((line = bestline(buffer)) != NULL) {
+				if (*line == 'y' || *line == 'Y') {
+					memcpy(&start[hlen + 1], hex, mdlen * 2);
+					trust = 1;
 				}
+				free(line);
 			}
-			munmap((void *)p, stbuf.st_size);
+			munmap((void *)p, size);
 		}
-		if (!found && (fp = fdopen(fd, "w")) != NULL) {
-			trust = fprintf(fp, "%s %s\n", host, hex) > 0;
-			fclose(fp);
-		} else close(fd);
-	} else return 0;
-
+	}
+	if (!found) trust = append_line(fd, "%s %s\n", host, hex);
+	close(fd);
 	return trust;
 }
 
@@ -727,10 +784,13 @@ static int do_download(Selector *sel, SSL **body, char **mime, int ask) {
 	struct stat stbuf;
 	const char *home;
 	SSL_CTX *ctx = NULL;
-	char *crlf, *meta = &data[3], *line, *url, *from;
-	int off, len, i, total, received, ret = 40, err = 0;
+	char *crlf, *meta = &data[3], *line, *url;
+	int redir, off, len, i, total, received, ret = 40, err = 0;
 	SSL *ssl = NULL;
 
+	if ((redir = perm_redirect(sel, NULL)) == 31) return 31;
+	else if (redir != 20) goto fail;
+
 	if ((home = getenv("XDG_DATA_HOME")) != NULL) {
 		if ((off = snprintf(crtpath, sizeof(crtpath), "%s/gplaces_%s", home, sel->host)) >= (int)sizeof(crtpath)) goto fail;;
 	} else if ((home = getenv("HOME")) == NULL || (off = snprintf(crtpath, sizeof(crtpath), "%s/.gplaces_%s", home, sel->host)) >= (int)sizeof(crtpath)) goto fail;
@@ -814,16 +874,8 @@ static int do_download(Selector *sel, SSL **body, char **mime, int ask) {
 
 		case '3':
 			if (!*meta) goto fail;
-			curl_free(sel->scheme); sel->scheme = NULL;
-			curl_free(sel->host); sel->host = NULL;
-			if (sel->port != defport) { curl_free(sel->port); }; sel->port = NULL;
-			curl_free(sel->path); sel->path = NULL;
-			curl_url_cleanup(sel->cu); sel->cu = NULL;
-			from = sel->url;
-			free(sel->rawurl); sel->rawurl = str_copy(meta);
-			if (!parse_url(sel, from, NULL)) { curl_free(from); goto fail; }
-			curl_free(from);
-			fprintf(stderr, "redirected to `%s`\n", sel->url);
+			if (data[1] == '1' && !perm_redirect(sel, meta)) goto fail;
+			else if (data[1] != '1' && !redirect(sel, meta, total - 2)) goto fail;
 			break;
 
 		case '6':