From 2af297d24bce4abf8d0f4723df9c27499dd51453 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?H=C3=A5vard=20Pettersson?= Date: Wed, 19 Nov 2014 11:49:53 +0100 Subject: [PATCH] Added an API for Tox DNS lookup. --- src/twc-dns.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/twc-dns.h | 39 ++++++++++++++ 2 files changed, 176 insertions(+) create mode 100644 src/twc-dns.c create mode 100644 src/twc-dns.h diff --git a/src/twc-dns.c b/src/twc-dns.c new file mode 100644 index 0000000..830f982 --- /dev/null +++ b/src/twc-dns.c @@ -0,0 +1,137 @@ +/* + * Copyright (c) 2014 Håvard Pettersson + * + * This file is part of Tox-WeeChat. + * + * Tox-WeeChat 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. + * + * Tox-WeeChat 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 Tox-WeeChat. If not, see . + */ + +#include +#include +#include +#include + +#include +#include + +#include "twc.h" +#include "twc-utils.h" + +#include "twc-dns.h" + +/** + * Struct for holding information about a Tox DNS query callback. + */ +struct t_twc_dns_callback_info +{ + void (*callback)(void *data, + enum t_twc_dns_rc rc, + const uint8_t *tox_id); + void *data; + + struct t_hook *hook; +}; + +/** + * Callback when the DNS resolver child process has written to our file + * descriptor. Process the data a bit and pass it on to the original callback. + */ +int +twc_dns_fd_callback(void *data, int fd) +{ + struct t_twc_dns_callback_info *callback_info = data; + + char buffer[TOX_FRIEND_ADDRESS_SIZE * 2 + 1]; + ssize_t size = read(fd, buffer, sizeof(buffer) - 1); + buffer[size] = '\0'; + + if (size > 0) + { + if (size == TOX_FRIEND_ADDRESS_SIZE * 2) + { + callback_info->callback(callback_info->data, + TWC_DNS_RC_OK, (uint8_t *)buffer); + } + else + { + int rc = atoi(buffer); + callback_info->callback(callback_info->data, + rc, NULL); + } + + weechat_unhook(callback_info->hook); + free(callback_info); + } + + return WEECHAT_RC_OK; +} + +/** + * Perform a Tox DNS lookup and write either a Tox ID (as a hexadecimal string) + * or an error code (as a decimal string) to out_fd. + */ +void +twc_perform_dns_lookup(const char *dns_id, int out_fd) +{ + dprintf(out_fd, "%d", TWC_DNS_RC_ERROR); +} + +/** + * Perform a Tox DNS lookup. If return code (rc) parameter in callback is + * TWC_DNS_RC_OK, tox_id contains the resolved Tox ID. For any other value, + * something caused the Tox ID not to be found. + * + * If twc_dns_query returns TWC_DNS_RC_ERROR, the callback will never be + * called. + */ +enum t_twc_dns_rc +twc_dns_query(const char *dns_id, + void (*callback)(void *data, + enum t_twc_dns_rc rc, + const uint8_t *tox_id), + void *callback_data) +{ + if (!callback) return TWC_DNS_RC_OK; + + int fifo[2]; + if (pipe(fifo) < 0) + return TWC_DNS_RC_ERROR; + + pid_t pid; + if ((pid = fork()) == -1) + { + return TWC_DNS_RC_ERROR; + } + else if (pid == 0) + { + twc_perform_dns_lookup(dns_id, fifo[1]); + _exit(0); + } + else + { + struct t_twc_dns_callback_info *callback_info + = malloc(sizeof(struct t_twc_dns_callback_info)); + if (!callback_info) + return TWC_DNS_RC_ERROR; + + callback_info->callback = callback; + callback_info->data = callback_data; + callback_info->hook = weechat_hook_fd(fifo[0], 1, 0, 0, + twc_dns_fd_callback, + callback_info); + } + + return TWC_DNS_RC_OK; +} + diff --git a/src/twc-dns.h b/src/twc-dns.h new file mode 100644 index 0000000..31fe64b --- /dev/null +++ b/src/twc-dns.h @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2014 Håvard Pettersson + * + * This file is part of Tox-WeeChat. + * + * Tox-WeeChat 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. + * + * Tox-WeeChat 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 Tox-WeeChat. If not, see . + */ + +#ifndef TOX_WEECHAT_DNS_H +#define TOX_WEECHAT_DNS_H + +#include + +enum t_twc_dns_rc +{ + TWC_DNS_RC_OK = 0, + TWC_DNS_RC_ERROR = -1, +}; + +enum t_twc_dns_rc +twc_dns_query(const char *dns_id, + void (*callback)(void *data, + enum t_twc_dns_rc rc, + const uint8_t *tox_id), + void *callback_data); + +#endif // TOX_WEECHAT_DNS_H +