Blindly implement login flow

1 files changed, 205 insertions, 0 deletions

diff --git a/irc.c b/irc.c
new file mode 100644
index 0000000..c1c0e7a
--- /dev/null
+++ b/irc.c
@@ -0,0 +1,205 @@
+/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <err.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sysexits.h>
+#include <tls.h>
+#include <unistd.h>
+
+#include "chat.h"
+
+struct tls *client;
+
+void ircConfig(bool insecure, const char *cert, const char *priv) {
+	struct tls_config *config = tls_config_new();
+	if (!config) errx(EX_SOFTWARE, "tls_config_new");
+
+	int error = tls_config_set_ciphers(config, "compat");
+	if (error) {
+		errx(
+			EX_SOFTWARE, "tls_config_set_ciphers: %s",
+			tls_config_error(config)
+		);
+	}
+
+	if (insecure) {
+		tls_config_insecure_noverifycert(config);
+		tls_config_insecure_noverifyname(config);
+	}
+
+	if (cert) {
+		error = tls_config_set_keypair_file(config, cert, (priv ? priv : cert));
+		if (error) {
+			errx(
+				EX_SOFTWARE, "tls_config_set_keypair_file: %s",
+				tls_config_error(config)
+			);
+		}
+	}
+
+	client = tls_client();
+	if (!client) errx(EX_SOFTWARE, "tls_client");
+
+	error = tls_configure(client, config);
+	if (error) errx(EX_SOFTWARE, "tls_configure: %s", tls_error(client));
+	tls_config_free(config);
+}
+
+int ircConnect(const char *host, const char *port) {
+	assert(client);
+
+	struct addrinfo *head;
+	struct addrinfo hints = {
+		.ai_family = AF_UNSPEC,
+		.ai_socktype = SOCK_STREAM,
+		.ai_protocol = IPPROTO_TCP,
+	};
+	int error = getaddrinfo(host, port, &hints, &head);
+	if (error) errx(EX_NOHOST, "%s:%s: %s", host, port, gai_strerror(error));
+
+	int sock = -1;
+	for (struct addrinfo *ai = head; ai; ai = ai->ai_next) {
+		sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+		if (sock < 0) err(EX_OSERR, "socket");
+
+		error = connect(sock, ai->ai_addr, ai->ai_addrlen);
+		if (!error) break;
+
+		close(sock);
+		sock = -1;
+	}
+	if (sock < 0) err(EX_UNAVAILABLE, "%s:%s", host, port);
+	freeaddrinfo(head);
+
+	error = tls_connect_socket(client, sock, host);
+	if (error) errx(EX_PROTOCOL, "tls_connect: %s", tls_error(client));
+
+	error = tls_handshake(client);
+	if (error) errx(EX_PROTOCOL, "tls_handshake: %s", tls_error(client));
+
+	return sock;
+}
+
+void ircSend(const char *ptr, size_t len) {
+	assert(client);
+	while (len) {
+		ssize_t ret = tls_write(client, ptr, len);
+		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) continue;
+		if (ret < 0) errx(EX_IOERR, "tls_write: %s", tls_error(client));
+		ptr += ret;
+		len -= ret;
+	}
+}
+
+void ircFormat(const char *format, ...) {
+	char buf[1024];
+	va_list ap;
+	va_start(ap, format);
+	int len = vsnprintf(buf, sizeof(buf), format, ap);
+	va_end(ap);
+	assert((size_t)len < sizeof(buf));
+	ircSend(buf, len);
+}
+
+static const char *TagNames[TagCap] = {
+#define X(name, id) [id] = name,
+	ENUM_TAG
+#undef X
+};
+
+static void unescape(char *tag) {
+	for (;;) {
+		tag = strchr(tag, '\\');
+		if (!tag) break;
+		switch (tag[1]) {
+			break; case ':': tag[1] = ';';
+			break; case 's': tag[1] = ' ';
+			break; case 'r': tag[1] = '\r';
+			break; case 'n': tag[1] = '\n';
+		}
+		memmove(tag, &tag[1], strlen(&tag[1]) + 1);
+		if (tag[0]) tag = &tag[1];
+	}
+}
+
+static struct Message parse(char *line) {
+	struct Message msg = { .cmd = NULL };
+
+	if (line[0] == '@') {
+		char *tags = 1 + strsep(&line, " ");
+		while (tags) {
+			char *tag = strsep(&tags, ";");
+			char *key = strsep(&tag, "=");
+			for (size_t i = 0; i < TagCap; ++i) {
+				if (strcmp(key, TagNames[i])) continue;
+				unescape(tag);
+				msg.tags[i] = tag;
+				break;
+			}
+		}
+	}
+
+	if (line[0] == ':') {
+		char *origin = 1 + strsep(&line, " ");
+		msg.nick = strsep(&origin, "!");
+		msg.user = strsep(&origin, "@");
+		msg.host = origin;
+	}
+
+	msg.cmd = strsep(&line, " ");
+	for (size_t i = 0; line && i < ParamCap; ++i) {
+		if (line[0] == ':') {
+			msg.params[i] = &line[1];
+			break;
+		}
+		msg.params[i] = strsep(&line, " ");
+	}
+
+	return msg;
+}
+
+void ircRecv(void) {
+	static char buf[8191 + 512];
+	static size_t len = 0;
+
+	assert(client);
+	ssize_t ret = tls_read(client, &buf[len], sizeof(buf) - len);
+	if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) return;
+	if (ret < 0) errx(EX_IOERR, "tls_read: %s", tls_error(client));
+	if (!ret) errx(EX_PROTOCOL, "server closed connection");
+	len += ret;
+
+	char *crlf;
+	char *line = buf;
+	for (;;) {
+		crlf = memmem(line, &buf[len] - line, "\r\n", 2);
+		if (!crlf) break;
+		*crlf = '\0';
+		handle(parse(line));
+		line = crlf + 2;
+	}
+
+	len -= line - buf;
+	memmove(buf, line, len);
+}