/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <wctype.h>
#include <db.h>
#include <err.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utmpx.h>
#include <wchar.h>
#include "finger.h"

static void cleanup(int sig);
static int do_protocol(const char *name, const struct addrinfo *ai);
static void trying(const struct addrinfo *ai);

void
netfinger(char *name)
{
        int error, multi;
        char *host;
        struct addrinfo *ai, *ai0;
        static struct addrinfo hint;

        host = strrchr(name, '@');
        if (host == NULL)
                return;
        *host++ = '\0';
        signal(SIGALRM, cleanup);
        alarm(TIME_LIMIT);

        hint.ai_flags = AI_CANONNAME;
        hint.ai_family = family;
        hint.ai_socktype = SOCK_STREAM;

        error = getaddrinfo(host, "finger", &hint, &ai0);
        if (error) {
                warnx("%s: %s", host, gai_strerror(error));
                return;
        }

        multi = (ai0->ai_next) != 0;

        /* ai_canonname may not be filled in if the user specified an IP. */
        if (ai0->ai_canonname == 0)
                printf("[%s]\n", host);
        else
                printf("[%s]\n", ai0->ai_canonname);

        for (ai = ai0; ai != NULL; ai = ai->ai_next) {
                if (multi)
                        trying(ai);

                error = do_protocol(name, ai);
                if (!error)
                        break;
        }
        alarm(0);
        freeaddrinfo(ai0);
}

static int
do_protocol(const char *name, const struct addrinfo *ai)
{
        int cnt, line_len, s;
        FILE *fp;
        wint_t c, lastc;
        struct iovec iov[3];
        struct msghdr msg;
        static char slash_w[] = "/W ";
        static char neteol[] = "\r\n";

        s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
        if (s < 0) {
                warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype,
                     ai->ai_protocol);
                return -1;
        }

        msg.msg_name = (void *)ai->ai_addr;
        msg.msg_namelen = ai->ai_addrlen;
        msg.msg_iov = iov;
        msg.msg_iovlen = 0;
        msg.msg_control = 0;
        msg.msg_controllen = 0;
        msg.msg_flags = 0;

        /* -l flag for remote fingerd  */
        if (lflag) {
                iov[msg.msg_iovlen].iov_base = slash_w;
                iov[msg.msg_iovlen++].iov_len = 3;
        }
        /* send the name followed by <CR><LF> */
        iov[msg.msg_iovlen].iov_base = strdup(name);
        iov[msg.msg_iovlen++].iov_len = strlen(name);
        iov[msg.msg_iovlen].iov_base = neteol;
        iov[msg.msg_iovlen++].iov_len = 2;

        if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
                warn("connect");
                close(s);
                return -1;
        }

        if (sendmsg(s, &msg, 0) < 0) {
                warn("sendmsg");
                close(s);
                return -1;
        }

        /*
         * Read from the remote system; once we're connected, we assume some
         * data.  If none arrives, we hang until the user interrupts.
         *
         * If we see a <CR> or a <CR> with the high bit set, treat it as
         * a newline; if followed by a newline character, only output one
         * newline.
         *
         * Otherwise, all high bits are stripped; if it isn't printable and
         * it isn't a space, we can simply set the 7th bit.  Every ASCII
         * character with bit 7 set is printable.
         */
        lastc = 0;
        if ((fp = fdopen(s, "r")) != NULL) {
                cnt = 0;
                line_len = 0;
                while ((c = getwc(fp)) != EOF) {
                        if (++cnt > OUTPUT_MAX) {
                                printf("\n\n Output truncated at %d bytes...\n",
                                        cnt - 1);
                                break;
                        }
                        if (c == 0x0d) {
                                if (lastc == '\r')      /* ^M^M - skip dupes */
                                        continue;
                                c = '\n';
                                lastc = '\r';
                        } else {
                                if (!iswprint(c) && !iswspace(c)) {
                                        c &= 0x7f;
                                        c |= 0x40;
                                }
                                if (lastc != '\r' || c != '\n')
                                        lastc = c;
                                else {
                                        lastc = '\n';
                                        continue;
                                }
                        }
                        putwchar(c);
                        if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) {
                                putchar('\\');
                                putchar('\n');
                                lastc = '\r';
                        }
                        if (lastc == '\n' || lastc == '\r')
                                line_len = 0;
                }
                if (ferror(fp)) {
                        /*
                         * Assume that whatever it was set errno...
                         */
                        warn("reading from network");
                }
                if (lastc != L'\n')
                        putchar('\n');

                fclose(fp);
        }
        return 0;
}

static void
trying(const struct addrinfo *ai)
{
        char buf[NI_MAXHOST];

        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf,
                        (char *)0, 0, NI_NUMERICHOST) != 0)
                return;         /* XXX can't happen */

        printf("Trying %s...\n", buf);
}

static void
cleanup(int sig __unused)
{
#define ERRSTR  "Timed out.\n"
        write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
        exit(1);
}