/*
 * testcode/streamtcp.c - debug program perform multiple DNS queries on tcp.
 *
 * Copyright (c) 2008, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This program performs multiple DNS queries on a TCP stream.
 */

#include "config.h"
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "util/locks.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/proxy_protocol.h"
#include "util/data/msgencode.h"
#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/data/dname.h"
#include "sldns/sbuffer.h"
#include "sldns/str2wire.h"
#include "sldns/wire2str.h"
#include <openssl/ssl.h>
#include <openssl/rand.h>
#include <openssl/err.h>

#ifndef PF_INET6
/** define in case streamtcp is compiled on legacy systems */
#define PF_INET6 10
#endif

/** usage information for streamtcp */
static void usage(char* argv[])
{
        printf("usage: %s [options] name type class ...\n", argv[0]);
        printf("        sends the name-type-class queries over TCP.\n");
        printf("-f server       what ipaddr@portnr to send the queries to\n");
        printf("-p client       what ipaddr@portnr to include in PROXYv2\n");
        printf("-u              use UDP. No retries are attempted.\n");
        printf("-n              do not wait for an answer.\n");
        printf("-a              print answers as they arrive.\n");
        printf("-d secs         delay after connection before sending query\n");
        printf("-s              use ssl\n");
        printf("-h              this help text\n");
        printf("IXFR=N          for the type, sends ixfr query with serial N.\n");
        printf("NOTIFY[=N]      for the type, sends notify. Can set new zone serial N.\n");
        exit(1);
}

/** open TCP socket to svr */
static int
open_svr(const char* svr, int udp, struct sockaddr_storage* addr,
        socklen_t* addrlen)
{
        int fd = -1;
        /* svr can be ip@port */
        memset(addr, 0, sizeof(*addr));
        if(!extstrtoaddr(svr, addr, addrlen, UNBOUND_DNS_PORT)) {
                printf("fatal: bad server specs '%s'\n", svr);
                exit(1);
        }
        fd = socket(addr_is_ip6(addr, *addrlen)?PF_INET6:PF_INET,
                udp?SOCK_DGRAM:SOCK_STREAM, 0);
        if(fd == -1) {
#ifndef USE_WINSOCK
                perror("socket() error");
#else
                printf("socket: %s\n", wsa_strerror(WSAGetLastError()));
#endif
                exit(1);
        }
        if(connect(fd, (struct sockaddr*)addr, *addrlen) < 0) {
#ifndef USE_WINSOCK
                perror("connect() error");
#else
                printf("connect: %s\n", wsa_strerror(WSAGetLastError()));
#endif
                exit(1);
        }
        return fd;
}

/** Append a SOA record with serial number */
static void
write_soa_serial_to_buf(sldns_buffer* buf, struct query_info* qinfo,
        uint32_t serial)
{
        sldns_buffer_set_position(buf, sldns_buffer_limit(buf));
        sldns_buffer_set_limit(buf, sldns_buffer_capacity(buf));
        /* Write compressed reference to the query */
        sldns_buffer_write_u16(buf, PTR_CREATE(LDNS_HEADER_SIZE));
        sldns_buffer_write_u16(buf, LDNS_RR_TYPE_SOA);
        sldns_buffer_write_u16(buf, qinfo->qclass);
        sldns_buffer_write_u32(buf, 3600); /* TTL */
        sldns_buffer_write_u16(buf, 1+1+4*5); /* rdatalen */
        sldns_buffer_write_u8(buf, 0); /* primary "." */
        sldns_buffer_write_u8(buf, 0); /* email "." */
        sldns_buffer_write_u32(buf, serial); /* serial */
        sldns_buffer_write_u32(buf, 0); /* refresh */
        sldns_buffer_write_u32(buf, 0); /* retry */
        sldns_buffer_write_u32(buf, 0); /* expire */
        sldns_buffer_write_u32(buf, 0); /* minimum */
        sldns_buffer_flip(buf);
}

/** write a query over the TCP fd */
static void
write_q(int fd, int udp, SSL* ssl, sldns_buffer* buf, uint16_t id,
        sldns_buffer* proxy_buf, int pp2_parsed,
        const char* strname, const char* strtype, const char* strclass)
{
        struct query_info qinfo;
        size_t proxy_buf_limit = sldns_buffer_limit(proxy_buf);
        int have_serial = 0, is_notify = 0;
        uint32_t serial = 0;
        /* qname */
        qinfo.qname = sldns_str2wire_dname(strname, &qinfo.qname_len);
        if(!qinfo.qname) {
                printf("cannot parse query name: '%s'\n", strname);
                exit(1);
        }

        /* qtype */
        if(strncasecmp(strtype, "IXFR=", 5) == 0) {
                serial = (uint32_t)atoi(strtype+5);
                have_serial = 1;
                qinfo.qtype = LDNS_RR_TYPE_IXFR;
        } else if(strcasecmp(strtype, "NOTIFY") == 0) {
                is_notify = 1;
                qinfo.qtype = LDNS_RR_TYPE_SOA;
        } else if(strncasecmp(strtype, "NOTIFY=", 7) == 0) {
                serial = (uint32_t)atoi(strtype+7);
                have_serial = 1;
                is_notify = 1;
                qinfo.qtype = LDNS_RR_TYPE_SOA;
        } else {
                qinfo.qtype = sldns_get_rr_type_by_name(strtype);
                if(qinfo.qtype == 0 && strcmp(strtype, "TYPE0") != 0) {
                        printf("cannot parse query type: '%s'\n", strtype);
                        exit(1);
                }
        }
        /* qclass */
        qinfo.qclass = sldns_get_rr_class_by_name(strclass);
        if(qinfo.qclass == 0 && strcmp(strclass, "CLASS0") != 0) {
                printf("cannot parse query class: '%s'\n", strclass);
                exit(1);
        }

        /* clear local alias */
        qinfo.local_alias = NULL;

        /* make query */
        qinfo_query_encode(buf, &qinfo);
        sldns_buffer_write_u16_at(buf, 0, id);
        sldns_buffer_write_u16_at(buf, 2, BIT_RD);

        if(have_serial && qinfo.qtype == LDNS_RR_TYPE_IXFR) {
                /* Attach serial to SOA record in the authority section. */
                write_soa_serial_to_buf(buf, &qinfo, serial);
                LDNS_NSCOUNT_SET(sldns_buffer_begin(buf), 1);
        }
        if(is_notify) {
                LDNS_OPCODE_SET(sldns_buffer_begin(buf), LDNS_PACKET_NOTIFY);
                LDNS_RD_CLR(sldns_buffer_begin(buf));
                LDNS_AA_SET(sldns_buffer_begin(buf));
                if(have_serial) {
                        write_soa_serial_to_buf(buf, &qinfo, serial);
                        LDNS_ANCOUNT_SET(sldns_buffer_begin(buf), 1);
                }
        }

        if(1) {
                /* add EDNS DO */
                struct edns_data edns;
                memset(&edns, 0, sizeof(edns));
                edns.edns_present = 1;
                edns.bits = EDNS_DO;
                edns.udp_size = 4096;
                if(sldns_buffer_capacity(buf) >=
                        sldns_buffer_limit(buf)+calc_edns_field_size(&edns))
                        attach_edns_record(buf, &edns);
        }

        /* we need to send the PROXYv2 information in every UDP message */
        if(udp && pp2_parsed) {
                /* append the proxy_buf with the buf's content
                 * and use that for sending */
                if(sldns_buffer_capacity(proxy_buf) <
                        sldns_buffer_limit(proxy_buf) +
                        sldns_buffer_limit(buf)) {
                        printf("buffer too small for packet + proxy");
                        exit(1);
                }
                sldns_buffer_clear(proxy_buf);
                sldns_buffer_skip(proxy_buf, proxy_buf_limit);
                sldns_buffer_write(proxy_buf, sldns_buffer_begin(buf),
                        sldns_buffer_limit(buf));
                sldns_buffer_flip(proxy_buf);
                buf = proxy_buf;
        }

        /* send it */
        if(!udp) {
                uint16_t len = (uint16_t)sldns_buffer_limit(buf);
                len = htons(len);
                if(ssl) {
                        if(SSL_write(ssl, (void*)&len, (int)sizeof(len)) <= 0) {
                                log_crypto_err("cannot SSL_write");
                                exit(1);
                        }
                } else {
                        if(send(fd, (void*)&len, sizeof(len), 0) <
                                (ssize_t)sizeof(len)){
#ifndef USE_WINSOCK
                                perror("send() len failed");
#else
                                printf("send len: %s\n",
                                        wsa_strerror(WSAGetLastError()));
#endif
                                exit(1);
                        }
                }
        }
        if(ssl) {
                if(SSL_write(ssl, (void*)sldns_buffer_begin(buf),
                        (int)sldns_buffer_limit(buf)) <= 0) {
                        log_crypto_err("cannot SSL_write");
                        exit(1);
                }
        } else {
                if(send(fd, (void*)sldns_buffer_begin(buf),
                        sldns_buffer_limit(buf), 0) <
                        (ssize_t)sldns_buffer_limit(buf)) {
#ifndef USE_WINSOCK
                        perror("send() data failed");
#else
                        printf("send data: %s\n",
                                wsa_strerror(WSAGetLastError()));
#endif
                        exit(1);
                }
        }

        /* reset the proxy_buf for next packet */
        sldns_buffer_set_limit(proxy_buf, proxy_buf_limit);
        free(qinfo.qname);
}

/** receive DNS datagram over TCP and print it */
static void
recv_one(int fd, int udp, SSL* ssl, sldns_buffer* buf)
{
        size_t i;
        char* pktstr;
        uint16_t len;
        if(!udp) {
                if(ssl) {
                        int sr = SSL_read(ssl, (void*)&len, (int)sizeof(len));
                        if(sr == 0) {
                                printf("ssl: stream closed\n");
                                exit(1);
                        }
                        if(sr < 0) {
                                log_crypto_err("could not SSL_read");
                                exit(1);
                        }
                } else {
                        ssize_t r = recv(fd, (void*)&len, sizeof(len), 0);
                        if(r == 0) {
                                printf("recv: stream closed\n");
                                exit(1);
                        }       
                        if(r < (ssize_t)sizeof(len)) {
#ifndef USE_WINSOCK
                                perror("read() len failed");
#else
                                printf("read len: %s\n",
                                        wsa_strerror(WSAGetLastError()));
#endif
                                exit(1);
                        }
                }
                len = ntohs(len);
                sldns_buffer_clear(buf);
                sldns_buffer_set_limit(buf, len);
                if(ssl) {
                        int r = SSL_read(ssl, (void*)sldns_buffer_begin(buf),
                                (int)len);
                        if(r <= 0) {
                                log_crypto_err("could not SSL_read");
                                exit(1);
                        }
                        if(r != (int)len)
                                fatal_exit("ssl_read %d of %d", r, len);
                } else {
                        if(recv(fd, (void*)sldns_buffer_begin(buf), len, 0) <
                                (ssize_t)len) {
#ifndef USE_WINSOCK
                                perror("read() data failed");
#else
                                printf("read data: %s\n",
                                        wsa_strerror(WSAGetLastError()));
#endif
                                exit(1);
                        }
                }
        } else {
                ssize_t l;
                sldns_buffer_clear(buf);
                if((l=recv(fd, (void*)sldns_buffer_begin(buf),
                        sldns_buffer_capacity(buf), 0)) < 0) {
#ifndef USE_WINSOCK
                        perror("read() data failed");
#else
                        printf("read data: %s\n",
                                wsa_strerror(WSAGetLastError()));
#endif
                        exit(1);
                }
                sldns_buffer_set_limit(buf, (size_t)l);
                len = (size_t)l;
        }
        printf("\nnext received packet\n");
        printf("data[%d] ", (int)sldns_buffer_limit(buf));
        for(i=0; i<sldns_buffer_limit(buf); i++) {
                const char* hex = "0123456789ABCDEF";
                printf("%c%c", hex[(sldns_buffer_read_u8_at(buf, i)&0xf0)>>4],
                        hex[sldns_buffer_read_u8_at(buf, i)&0x0f]);
        }
        printf("\n");

        pktstr = sldns_wire2str_pkt(sldns_buffer_begin(buf), len);
        printf("%s", pktstr);
        free(pktstr);
}

/** see if we can receive any results */
static void
print_any_answers(int fd, int udp, SSL* ssl, sldns_buffer* buf,
        int* num_answers, int wait_all)
{
        /* see if the fd can read, if so, print one answer, repeat */
        int ret;
        struct timeval tv, *waittv;
        fd_set rfd;
        while(*num_answers > 0) {
                memset(&rfd, 0, sizeof(rfd));
                memset(&tv, 0, sizeof(tv));
                FD_ZERO(&rfd);
                FD_SET(fd, &rfd);
                if(wait_all) waittv = NULL;
                else waittv = &tv;
                ret = select(fd+1, &rfd, NULL, NULL, waittv);
                if(ret < 0) {
                        if(errno == EINTR || errno == EAGAIN) continue;
                        perror("select() failed");
                        exit(1);
                }
                if(ret == 0) {
                        if(wait_all) continue;
                        return;
                }
                (*num_answers) -= 1;
                recv_one(fd, udp, ssl, buf);
        }
}

static int get_random(void)
{
        int r;
        if (RAND_bytes((unsigned char*)&r, (int)sizeof(r)) == 1) {
                return r;
        }
        return (int)arc4random();
}

/* parse the pp2_client and populate the proxy_buffer
 * It doesn't populate the destination parts. */
static int parse_pp2_client(const char* pp2_client, int udp,
        sldns_buffer* proxy_buf)
{
        struct sockaddr_storage pp2_addr;
        size_t bytes_written;
        socklen_t pp2_addrlen = 0;
        memset(&pp2_addr, 0, sizeof(pp2_addr));
        if(*pp2_client == 0) return 0;
        if(!extstrtoaddr(pp2_client, &pp2_addr, &pp2_addrlen, UNBOUND_DNS_PORT)) {
                printf("fatal: bad proxy client specs '%s'\n", pp2_client);
                exit(1);
        }
        sldns_buffer_clear(proxy_buf);
        bytes_written = pp2_write_to_buf(sldns_buffer_begin(proxy_buf),
                sldns_buffer_remaining(proxy_buf), &pp2_addr, !udp);
        sldns_buffer_set_position(proxy_buf, bytes_written);
        sldns_buffer_flip(proxy_buf);
        return 1;
}

/** send the TCP queries and print answers */
static void
send_em(const char* svr, const char* pp2_client, int udp, int usessl,
        int noanswer, int onarrival, int delay, int num, char** qs)
{
        struct sockaddr_storage svr_addr;
        socklen_t svr_addrlen;
        int fd = open_svr(svr, udp, &svr_addr, &svr_addrlen);
        int i, wait_results = 0, pp2_parsed;
        SSL_CTX* ctx = NULL;
        SSL* ssl = NULL;
        sldns_buffer* buf = sldns_buffer_new(65553);
        sldns_buffer* proxy_buf = sldns_buffer_new(65553);
        if(!buf || !proxy_buf) {
                sldns_buffer_free(buf);
                sldns_buffer_free(proxy_buf);
                fatal_exit("out of memory");
        }
        pp2_parsed = parse_pp2_client(pp2_client, udp, proxy_buf);
        if(usessl) {
                ctx = connect_sslctx_create(NULL, NULL, NULL, 0);
                if(!ctx) fatal_exit("cannot create ssl ctx");
                ssl = outgoing_ssl_fd(ctx, fd);
                if(!ssl) fatal_exit("cannot create ssl");
                while(1) {
                        int r;
                        ERR_clear_error();
                        if( (r=SSL_do_handshake(ssl)) == 1)
                                break;
                        r = SSL_get_error(ssl, r);
                        if(r != SSL_ERROR_WANT_READ &&
                                r != SSL_ERROR_WANT_WRITE) {
                                log_crypto_err_io("could not ssl_handshake", r);
                                exit(1);
                        }
                }
                if(1) {
#ifdef HAVE_SSL_GET1_PEER_CERTIFICATE
                        X509* x = SSL_get1_peer_certificate(ssl);
#else
                        X509* x = SSL_get_peer_certificate(ssl);
#endif
                        if(!x) printf("SSL: no peer certificate\n");
                        else {
                                X509_print_fp(stdout, x);
                                X509_free(x);
                        }
                }
        }
        /* Send the PROXYv2 information once per stream */
        if(!udp && pp2_parsed) {
                if(ssl) {
                        if(SSL_write(ssl, (void*)sldns_buffer_begin(proxy_buf),
                                (int)sldns_buffer_limit(proxy_buf)) <= 0) {
                                log_crypto_err("cannot SSL_write");
                                exit(1);
                        }
                } else {
                        if(send(fd, (void*)sldns_buffer_begin(proxy_buf),
                                sldns_buffer_limit(proxy_buf), 0) <
                                (ssize_t)sldns_buffer_limit(proxy_buf)) {
#ifndef USE_WINSOCK
                                perror("send() data failed");
#else
                                printf("send data: %s\n",
                                        wsa_strerror(WSAGetLastError()));
#endif
                                exit(1);
                        }
                }
        }
        for(i=0; i<num; i+=3) {
                if (delay != 0) {
#ifdef HAVE_SLEEP
                        sleep((unsigned)delay);
#else
                        Sleep(delay*1000);
#endif
                }
                printf("\nNext query is %s %s %s\n", qs[i], qs[i+1], qs[i+2]);
                write_q(fd, udp, ssl, buf, (uint16_t)get_random(), proxy_buf,
                        pp2_parsed,
                        qs[i], qs[i+1], qs[i+2]);
                /* print at least one result */
                if(onarrival) {
                        wait_results += 1; /* one more answer to fetch */
                        print_any_answers(fd, udp, ssl, buf, &wait_results, 0);
                } else if(!noanswer) {
                        recv_one(fd, udp, ssl, buf);
                }
        }
        if(onarrival)
                print_any_answers(fd, udp, ssl, buf, &wait_results, 1);

        if(usessl) {
                SSL_shutdown(ssl);
                SSL_free(ssl);
                SSL_CTX_free(ctx);
        }
        sock_close(fd);
        sldns_buffer_free(buf);
        sldns_buffer_free(proxy_buf);
        printf("orderly exit\n");
}

#ifdef SIGPIPE
/** SIGPIPE handler */
static RETSIGTYPE sigh(int sig)
{
        char str[] = "Got unhandled signal   \n";
        if(sig == SIGPIPE) {
                char* strpipe = "got SIGPIPE, remote connection gone\n";
                /* simple cast to void will not silence Wunused-result */
                (void)!write(STDOUT_FILENO, strpipe, strlen(strpipe));
                exit(1);
        }
        str[21] = '0' + (sig/10)%10;
        str[22] = '0' + sig%10;
        /* simple cast to void will not silence Wunused-result */
        (void)!write(STDOUT_FILENO, str, strlen(str));
        exit(1);
}
#endif /* SIGPIPE */

/** getopt global, in case header files fail to declare it. */
extern int optind;
/** getopt global, in case header files fail to declare it. */
extern char* optarg;

/** main program for streamtcp */
int main(int argc, char** argv)
{
        int c;
        const char* svr = "127.0.0.1";
        const char* pp2_client = "";
        int udp = 0;
        int noanswer = 0;
        int onarrival = 0;
        int usessl = 0;
        int delay = 0;

#ifdef USE_WINSOCK
        WSADATA wsa_data;
        if(WSAStartup(MAKEWORD(2,2), &wsa_data) != 0) {
                printf("WSAStartup failed\n");
                return 1;
        }
#endif

        /* lock debug start (if any) */
        checklock_start();
        log_init(0, 0, 0);

#ifdef SIGPIPE
        if(signal(SIGPIPE, &sigh) == SIG_ERR) {
                perror("could not install signal handler");
                return 1;
        }
#endif

        /* command line options */
        if(argc == 1) {
                usage(argv);
        }
        while( (c=getopt(argc, argv, "af:p:hnsud:")) != -1) {
                switch(c) {
                        case 'f':
                                svr = optarg;
                                break;
                        case 'p':
                                pp2_client = optarg;
                                pp_init(&sldns_write_uint16,
                                        &sldns_write_uint32);
                                break;
                        case 'a':
                                onarrival = 1;
                                break;
                        case 'n':
                                noanswer = 1;
                                break;
                        case 'u':
                                udp = 1;
                                break;
                        case 's':
                                usessl = 1;
                                break;
                        case 'd':
                                if(atoi(optarg)==0 && strcmp(optarg,"0")!=0) {
                                        printf("error parsing delay, "
                                            "number expected: %s\n", optarg);
                                        return 1;
                                }
                                delay = atoi(optarg);
                                break;
                        case 'h':
                        case '?':
                        default:
                                usage(argv);
                }
        }
        argc -= optind;
        argv += optind;

        if(argc % 3 != 0) {
                printf("queries must be multiples of name,type,class\n");
                return 1;
        }
        if(usessl) {
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_SSL)
                ERR_load_SSL_strings();
#endif
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_CRYPTO)
#  ifndef S_SPLINT_S
                OpenSSL_add_all_algorithms();
#  endif
#else
                OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
                        | OPENSSL_INIT_ADD_ALL_DIGESTS
                        | OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL);
#endif
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_SSL)
                (void)SSL_library_init();
#else
                (void)OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS, NULL);
#endif
        }
        send_em(svr, pp2_client, udp, usessl, noanswer, onarrival, delay, argc, argv);
        checklock_stop();
#ifdef USE_WINSOCK
        WSACleanup();
#endif
        return 0;
}