/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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/types.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <ctype.h>
#include <err.h>
#include <stdlib.h>
#include <unistd.h>

int     rexecoptions;

/*
 * Options and other state info.
 */
struct macel {
        char mac_name[9];       /* macro name */
        char *mac_start;        /* start of macro in macbuf */
        char *mac_end;          /* end of macro in macbuf */
};

int macnum;                     /* number of defined macros */
struct macel macros[16];
char macbuf[4096];

static  FILE *cfile;

#define DEFAULT 1
#define LOGIN   2
#define PASSWD  3
#define ACCOUNT 4
#define MACDEF  5
#define ID      10
#define MACH    11

static char tokval[100];

static struct toktab {
        char *tokstr;
        int tval;
} toktab[]= {
        { "default",    DEFAULT },
        { "login",      LOGIN },
        { "password",   PASSWD },
        { "passwd",     PASSWD },
        { "account",    ACCOUNT },
        { "machine",    MACH },
        { "macdef",     MACDEF },
        { NULL,         0 }
};

static int
token()
{
        char *cp;
        int c;
        struct toktab *t;

        if (feof(cfile) || ferror(cfile))
                return (0);
        while ((c = getc(cfile)) != EOF &&
            (c == '\n' || c == '\t' || c == ' ' || c == ','))
                continue;
        if (c == EOF)
                return (0);
        cp = tokval;
        if (c == '"') {
                while ((c = getc(cfile)) != EOF && c != '"') {
                        if (c == '\\')
                                c = getc(cfile);
                        *cp++ = c;
                }
        } else {
                *cp++ = c;
                while ((c = getc(cfile)) != EOF
                    && c != '\n' && c != '\t' && c != ' ' && c != ',') {
                        if (c == '\\')
                                c = getc(cfile);
                        *cp++ = c;
                }
        }
        *cp = 0;
        if (tokval[0] == 0)
                return (0);
        for (t = toktab; t->tokstr; t++)
                if (!strcmp(t->tokstr, tokval))
                        return (t->tval);
        return (ID);
}

static int
ruserpass(char *host, char **aname, char **apass, char **aacct)
{
        char *hdir, buf[BUFSIZ], *tmp;
        char myname[MAXHOSTNAMELEN], *mydomain;
        int t, i, c, usedefault = 0;
        struct stat stb;

        hdir = getenv("HOME");
        if (hdir == NULL)
                hdir = ".";
        if (strlen(hdir) + 8 > sizeof(buf))
                return (0);
        (void) sprintf(buf, "%s/.netrc", hdir);
        cfile = fopen(buf, "r");
        if (cfile == NULL) {
                if (errno != ENOENT)
                        warn("%s", buf);
                return (0);
        }
        if (gethostname(myname, sizeof(myname)) < 0)
                myname[0] = '\0';
        if ((mydomain = strchr(myname, '.')) == NULL)
                mydomain = "";
next:
        while ((t = token())) switch(t) {

        case DEFAULT:
                usedefault = 1;
                /* FALL THROUGH */

        case MACH:
                if (!usedefault) {
                        if (token() != ID)
                                continue;
                        /*
                         * Allow match either for user's input host name
                         * or official hostname.  Also allow match of
                         * incompletely-specified host in local domain.
                         */
                        if (strcasecmp(host, tokval) == 0)
                                goto match;
                        if ((tmp = strchr(host, '.')) != NULL &&
                            strcasecmp(tmp, mydomain) == 0 &&
                            strncasecmp(host, tokval, tmp - host) == 0 &&
                            tokval[tmp - host] == '\0')
                                goto match;
                        continue;
                }
        match:
                while ((t = token()) && t != MACH && t != DEFAULT) switch(t) {

                case LOGIN:
                        if (token())
                                if (*aname == NULL) {
                                        *aname = malloc((unsigned) strlen(tokval) + 1);
                                        (void) strcpy(*aname, tokval);
                                } else {
                                        if (strcmp(*aname, tokval))
                                                goto next;
                                }
                        break;
                case PASSWD:
                        if ((*aname == NULL || strcmp(*aname, "anonymous")) &&
                            fstat(fileno(cfile), &stb) >= 0 &&
                            (stb.st_mode & 077) != 0) {
        warnx("Error: .netrc file is readable by others.");
        warnx("Remove password or make file unreadable by others.");
                                goto bad;
                        }
                        if (token() && *apass == NULL) {
                                *apass = malloc((unsigned) strlen(tokval) + 1);
                                (void) strcpy(*apass, tokval);
                        }
                        break;
                case ACCOUNT:
                        if (fstat(fileno(cfile), &stb) >= 0
                            && (stb.st_mode & 077) != 0) {
        warnx("Error: .netrc file is readable by others.");
        warnx("Remove account or make file unreadable by others.");
                                goto bad;
                        }
                        if (token() && *aacct == NULL) {
                                *aacct = malloc((unsigned) strlen(tokval) + 1);
                                (void) strcpy(*aacct, tokval);
                        }
                        break;
                case MACDEF:
                        while ((c=getc(cfile)) != EOF &&
                                                (c == ' ' || c == '\t'))
                                ;
                        if (c == EOF || c == '\n') {
                                printf("Missing macdef name argument.\n");
                                goto bad;
                        }
                        if (macnum == 16) {
                                printf("Limit of 16 macros have already been defined\n");
                                goto bad;
                        }
                        tmp = macros[macnum].mac_name;
                        *tmp++ = c;
                        for (i=0; i < 8 && (c=getc(cfile)) != EOF &&
                            !isspace(c); ++i) {
                                *tmp++ = c;
                        }
                        if (c == EOF) {
                                printf("Macro definition missing null line terminator.\n");
                                goto bad;
                        }
                        *tmp = '\0';
                        if (c != '\n') {
                                while ((c=getc(cfile)) != EOF && c != '\n');
                        }
                        if (c == EOF) {
                                printf("Macro definition missing null line terminator.\n");
                                goto bad;
                        }
                        if (macnum == 0) {
                                macros[macnum].mac_start = macbuf;
                        }
                        else {
                                macros[macnum].mac_start = macros[macnum-1].mac_end + 1;
                        }
                        tmp = macros[macnum].mac_start;
                        while (tmp != macbuf + 4096) {
                                if ((c=getc(cfile)) == EOF) {
                                printf("Macro definition missing null line terminator.\n");
                                        goto bad;
                                }
                                *tmp = c;
                                if (*tmp == '\n') {
                                        if (*(tmp-1) == '\0') {
                                           macros[macnum++].mac_end = tmp - 1;
                                           break;
                                        }
                                        *tmp = '\0';
                                }
                                tmp++;
                        }
                        if (tmp == macbuf + 4096) {
                                printf("4K macro buffer exceeded\n");
                                goto bad;
                        }
                        break;
                default:
                        warnx("Unknown .netrc keyword %s", tokval);
                        break;
                }
                goto done;
        }
done:
        (void) fclose(cfile);
        return (0);
bad:
        (void) fclose(cfile);
        return (-1);
}

int
rexec(char **ahost, int rport, char *name, char *pass, char *cmd, int *fd2p)
{
        struct sockaddr_in sin, sin2, from;
        struct hostent *hp;
        u_short port;
        int s, timo = 1, s3;
        char c, *acct;

        hp = gethostbyname(*ahost);
        if (hp == NULL) {
                herror(*ahost);
                return (-1);
        }
        *ahost = hp->h_name;
        acct = NULL;
        ruserpass(hp->h_name, &name, &pass, &acct);
        free(acct);
retry:
        s = socket(AF_INET, SOCK_STREAM, 0);
        if (s < 0) {
                perror("rexec: socket");
                return (-1);
        }
        sin.sin_family = hp->h_addrtype;
        sin.sin_port = rport;
        bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
        if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
                if (errno == ECONNREFUSED && timo <= 16) {
                        (void) close(s);
                        sleep(timo);
                        timo *= 2;
                        goto retry;
                }
                perror(hp->h_name);
                (void) close(s);
                return (-1);
        }
        port = 0;
        if (fd2p == 0)
                (void) write(s, "", 1); 
        else {
                char num[8];
                int s2, sin2len;

                s2 = socket(AF_INET, SOCK_STREAM, 0);
                if (s2 < 0) {
                        (void) close(s);
                        return (-1);
                }
                listen(s2, 1);
                sin2len = sizeof (sin2);
                if (getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
                  sin2len != sizeof (sin2)) {
                        perror("getsockname");
                        (void) close(s2);
                        goto bad;
                }
                port = ntohs((u_short)sin2.sin_port);
                (void) sprintf(num, "%hu", port);
                (void) write(s, num, strlen(num)+1);
                { int len = sizeof (from);
                  s3 = accept(s2, (struct sockaddr *)&from, &len);
                  close(s2);
                  if (s3 < 0) {
                        perror("accept");
                        port = 0;
                        goto bad;
                  }
                }
                *fd2p = s3;
        }
        (void) write(s, name, strlen(name) + 1);
        /* should public key encypt the password here */
        (void) write(s, pass, strlen(pass) + 1);
        (void) write(s, cmd, strlen(cmd) + 1);
        if (read(s, &c, 1) != 1) {
                perror(*ahost);
                goto bad;
        }
        if (c != 0) {
                while (read(s, &c, 1) == 1) {
                        (void) write(2, &c, 1);
                        if (c == '\n')
                                break;
                }
                goto bad;
        }
        return (s);
bad:
        if (port)
                (void) close(*fd2p);
        (void) close(s);
        return (-1);
}