catboy/irc.c

310 lines
8.0 KiB
C

/* 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/>.
*
* Additional permission under GNU GPL version 3 section 7:
*
* If you modify this Program, or any covered work, by linking or
* combining it with OpenSSL (or a modified version of that library),
* containing parts covered by the terms of the OpenSSL License and the
* original SSLeay license, the licensors of this Program grant you
* additional permission to convey the resulting work. Corresponding
* Source for a non-source form of such a combination shall include the
* source code for the parts of OpenSSL used as well as that of the
* covered work.
*/
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <fcntl.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 <sys/stat.h>
#include <sysexits.h>
#include <tls.h>
#include <unistd.h>
#include "chat.h"
static struct tls *client;
static struct tls_config *config;
void ircConfig(
bool insecure, const char *trust, const char *cert, const char *priv
) {
config = tls_config_new();
if (!config) errx(EX_SOFTWARE, "tls_config_new");
int error;
if (insecure) {
tls_config_insecure_noverifycert(config);
tls_config_insecure_noverifyname(config);
}
if (trust) {
tls_config_insecure_noverifyname(config);
const char *dirs = NULL;
for (const char *path; NULL != (path = configPath(&dirs, trust));) {
error = tls_config_set_ca_file(config, path);
if (!error) break;
}
if (error) errx(EX_NOINPUT, "%s: %s", trust, tls_config_error(config));
}
// Explicitly load the default CA cert file on OpenBSD now so it doesn't
// need to be unveiled. Other systems might use a CA directory, so avoid
// changing the default behavior.
#ifdef __OpenBSD__
if (!insecure && !trust) {
const char *ca = tls_default_ca_cert_file();
error = tls_config_set_ca_file(config, ca);
if (error) errx(EX_OSFILE, "%s: %s", ca, tls_config_error(config));
}
#endif
if (cert) {
const char *dirs = NULL;
for (const char *path; NULL != (path = configPath(&dirs, cert));) {
if (priv) {
error = tls_config_set_cert_file(config, path);
} else {
error = tls_config_set_keypair_file(config, path, path);
}
if (!error) break;
}
if (error) errx(EX_NOINPUT, "%s: %s", cert, tls_config_error(config));
}
if (priv) {
const char *dirs = NULL;
for (const char *path; NULL != (path = configPath(&dirs, priv));) {
error = tls_config_set_key_file(config, path);
if (!error) break;
}
if (error) errx(EX_NOINPUT, "%s: %s", priv, 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));
}
int ircConnect(const char *bindHost, const char *host, const char *port) {
assert(client);
int error;
int sock = -1;
struct addrinfo *head;
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP,
};
if (bindHost) {
error = getaddrinfo(bindHost, NULL, &hints, &head);
if (error) errx(EX_NOHOST, "%s: %s", bindHost, gai_strerror(error));
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 = bind(sock, ai->ai_addr, ai->ai_addrlen);
if (!error) {
hints.ai_family = ai->ai_family;
break;
}
close(sock);
sock = -1;
}
if (sock < 0) err(EX_UNAVAILABLE, "%s", bindHost);
freeaddrinfo(head);
}
error = getaddrinfo(host, port, &hints, &head);
if (error) errx(EX_NOHOST, "%s:%s: %s", host, port, gai_strerror(error));
for (struct addrinfo *ai = head; ai; ai = ai->ai_next) {
if (sock < 0) {
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;
if (error && errno == EINTR) break; // connect continues asynchronously
close(sock);
sock = -1;
}
if (sock < 0) err(EX_UNAVAILABLE, "%s:%s", host, port);
freeaddrinfo(head);
fcntl(sock, F_SETFD, FD_CLOEXEC);
error = tls_connect_socket(client, sock, host);
if (error) errx(EX_PROTOCOL, "tls_connect: %s", tls_error(client));
return sock;
}
void ircHandshake(void) {
int error;
do {
error = tls_handshake(client);
} while (error == TLS_WANT_POLLIN || error == TLS_WANT_POLLOUT);
if (error) errx(EX_PROTOCOL, "tls_handshake: %s", tls_error(client));
tls_config_clear_keys(config);
}
void ircPrintCert(void) {
size_t len;
ircHandshake();
const byte *pem = tls_peer_cert_chain_pem(client, &len);
printf("subject= %s\n", tls_peer_cert_subject(client));
fwrite(pem, len, 1, stdout);
}
enum { MessageCap = 8191 + 512 };
static void debug(const char *pre, const char *line) {
if (!self.debug) return;
size_t len = strcspn(line, "\r\n");
uiFormat(
Debug, Cold, NULL, "\3%02d%s\3\t%.*s",
Gray, pre, (int)len, line
);
if (!isatty(STDERR_FILENO)) {
fprintf(stderr, "%s %.*s\n", pre, (int)len, line);
}
}
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[MessageCap];
va_list ap;
va_start(ap, format);
int len = vsnprintf(buf, sizeof(buf), format, ap);
va_end(ap);
assert((size_t)len < sizeof(buf));
debug("<<", 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 (uint 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 (uint 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[MessageCap];
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';
debug(">>", line);
struct Message msg = parse(line);
handle(&msg);
line = crlf + 2;
}
len -= line - buf;
memmove(buf, line, len);
}
void ircClose(void) {
tls_close(client);
tls_free(client);
}