/*-
 * 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 "rcv.h"
#include "extern.h"

/*
 * Mail -- a mail program
 *
 * Mail to others.
 */

/*
 * Send message described by the passed pointer to the
 * passed output buffer.  Return -1 on error.
 * Adjust the status: field if need be.
 * If doign is given, suppress ignored header fields.
 * prefix is a string to prepend to each output line.
 */
int
sendmessage(struct message *mp, FILE *obuf, struct ignoretab *doign,
        char *prefix)
{
        long count;
        FILE *ibuf;
        char *cp, *cp2, line[LINESIZE];
        int ishead, infld, ignoring, dostat, firstline;
        int c = 0, length, prefixlen;

        /*
         * Compute the prefix string, without trailing whitespace
         */
        if (prefix != NULL) {
                cp2 = 0;
                for (cp = prefix; *cp != '\0'; cp++)
                        if (*cp != ' ' && *cp != '\t')
                                cp2 = cp;
                prefixlen = cp2 == NULL ? 0 : cp2 - prefix + 1;
        }
        ibuf = setinput(mp);
        count = mp->m_size;
        ishead = 1;
        dostat = doign == 0 || !isign("status", doign);
        infld = 0;
        firstline = 1;
        /*
         * Process headers first
         */
        while (count > 0 && ishead) {
                if (fgets(line, sizeof(line), ibuf) == NULL)
                        break;
                count -= length = strlen(line);
                if (firstline) {
                        /*
                         * First line is the From line, so no headers
                         * there to worry about
                         */
                        firstline = 0;
                        ignoring = doign == ignoreall;
                } else if (line[0] == '\n') {
                        /*
                         * If line is blank, we've reached end of
                         * headers, so force out status: field
                         * and note that we are no longer in header
                         * fields
                         */
                        if (dostat) {
                                statusput(mp, obuf, prefix);
                                dostat = 0;
                        }
                        ishead = 0;
                        ignoring = doign == ignoreall;
                } else if (infld && (line[0] == ' ' || line[0] == '\t')) {
                        /*
                         * If this line is a continuation (via space or tab)
                         * of a previous header field, just echo it
                         * (unless the field should be ignored).
                         * In other words, nothing to do.
                         */
                } else {
                        /*
                         * Pick up the header field if we have one.
                         */
                        for (cp = line; (c = *cp++) != '\0' && c != ':' &&
                            !isspace((unsigned char)c);)
                                ;
                        cp2 = --cp;
                        while (isspace((unsigned char)*cp++))
                                ;
                        if (cp[-1] != ':') {
                                /*
                                 * Not a header line, force out status:
                                 * This happens in uucp style mail where
                                 * there are no headers at all.
                                 */
                                if (dostat) {
                                        statusput(mp, obuf, prefix);
                                        dostat = 0;
                                }
                                if (doign != ignoreall)
                                        /* add blank line */
                                        (void)putc('\n', obuf);
                                ishead = 0;
                                ignoring = 0;
                        } else {
                                /*
                                 * If it is an ignored field and
                                 * we care about such things, skip it.
                                 */
                                *cp2 = '\0';    /* temporarily null terminate */
                                if (doign && isign(line, doign))
                                        ignoring = 1;
                                else if ((line[0] == 's' || line[0] == 'S') &&
                                         strcasecmp(line, "status") == 0) {
                                        /*
                                         * If the field is "status," go compute
                                         * and print the real Status: field
                                         */
                                        if (dostat) {
                                                statusput(mp, obuf, prefix);
                                                dostat = 0;
                                        }
                                        ignoring = 1;
                                } else {
                                        ignoring = 0;
                                        *cp2 = c;       /* restore */
                                }
                                infld = 1;
                        }
                }
                if (!ignoring) {
                        /*
                         * Strip trailing whitespace from prefix
                         * if line is blank.
                         */
                        if (prefix != NULL) {
                                if (length > 1)
                                        fputs(prefix, obuf);
                                else
                                        (void)fwrite(prefix, sizeof(*prefix),
                                            prefixlen, obuf);
                        }
                        (void)fwrite(line, sizeof(*line), length, obuf);
                        if (ferror(obuf))
                                return (-1);
                }
        }
        /*
         * Copy out message body
         */
        if (doign == ignoreall)
                count--;                /* skip final blank line */
        if (prefix != NULL)
                while (count > 0) {
                        if (fgets(line, sizeof(line), ibuf) == NULL) {
                                c = 0;
                                break;
                        }
                        count -= c = strlen(line);
                        /*
                         * Strip trailing whitespace from prefix
                         * if line is blank.
                         */
                        if (c > 1)
                                fputs(prefix, obuf);
                        else
                                (void)fwrite(prefix, sizeof(*prefix),
                                    prefixlen, obuf);
                        (void)fwrite(line, sizeof(*line), c, obuf);
                        if (ferror(obuf))
                                return (-1);
                }
        else
                while (count > 0) {
                        c = count < LINESIZE ? count : LINESIZE;
                        if ((c = fread(line, sizeof(*line), c, ibuf)) <= 0)
                                break;
                        count -= c;
                        if (fwrite(line, sizeof(*line), c, obuf) != c)
                                return (-1);
                }
        if (doign == ignoreall && c > 0 && line[c - 1] != '\n')
                /* no final blank line */
                if ((c = getc(ibuf)) != EOF && putc(c, obuf) == EOF)
                        return (-1);
        return (0);
}

/*
 * Output a reasonable looking status field.
 */
void
statusput(struct message *mp, FILE *obuf, char *prefix)
{
        char statout[3];
        char *cp = statout;

        if (mp->m_flag & MREAD)
                *cp++ = 'R';
        if ((mp->m_flag & MNEW) == 0)
                *cp++ = 'O';
        *cp = '\0';
        if (statout[0] != '\0')
                fprintf(obuf, "%sStatus: %s\n",
                        prefix == NULL ? "" : prefix, statout);
}

/*
 * Interface between the argument list and the mail1 routine
 * which does all the dirty work.
 */
int
mail(struct name *to, struct name *cc, struct name *bcc, struct name *smopts,
        char *subject, char *replyto)
{
        struct header head;

        head.h_to = to;
        head.h_subject = subject;
        head.h_cc = cc;
        head.h_bcc = bcc;
        head.h_smopts = smopts;
        head.h_replyto = replyto;
        head.h_inreplyto = NULL;
        mail1(&head, 0);
        return (0);
}


/*
 * Send mail to a bunch of user names.  The interface is through
 * the mail routine below.
 */
int
sendmail(void *str)
{
        struct header head;

        head.h_to = extract(str, GTO);
        head.h_subject = NULL;
        head.h_cc = NULL;
        head.h_bcc = NULL;
        head.h_smopts = NULL;
        head.h_replyto = value("REPLYTO");
        head.h_inreplyto = NULL;
        mail1(&head, 0);
        return (0);
}

/*
 * Mail a message on standard input to the people indicated
 * in the passed header.  (Internal interface).
 */
void
mail1(struct header *hp, int printheaders)
{
        char *cp;
        char *nbuf;
        int pid;
        char **namelist;
        struct name *to, *nsto;
        FILE *mtf;

        /*
         * Collect user's mail from standard input.
         * Get the result as mtf.
         */
        if ((mtf = collect(hp, printheaders)) == NULL) {
                senderr++;
                return;
        }
        if (value("interactive") != NULL) {
                if (value("askcc") != NULL || value("askbcc") != NULL) {
                        if (value("askcc") != NULL)
                                grabh(hp, GCC);
                        if (value("askbcc") != NULL)
                                grabh(hp, GBCC);
                } else {
                        printf("EOT\n");
                        (void)fflush(stdout);
                }
        }
        if (fsize(mtf) == 0) {
                if (value("dontsendempty") != NULL)
                        goto out;
                if (hp->h_subject == NULL)
                        printf("No message, no subject; hope that's ok\n");
                else
                        printf("Null message body; hope that's ok\n");
        }
        /*
         * Now, take the user names from the combined
         * to and cc lists and do all the alias
         * processing.
         */
        senderr = 0;
        to = usermap(cat(hp->h_bcc, cat(hp->h_to, hp->h_cc)));
        if (to == NULL) {
                printf("No recipients specified\n");
                senderr++;
        }
        /*
         * Look through the recipient list for names with /'s
         * in them which we write to as files directly.
         */
        to = outof(to, mtf, hp);
        if (senderr)
                savedeadletter(mtf);
        to = elide(to);
        if (count(to) == 0)
                goto out;
        if (value("recordrecip") != NULL) {
                /*
                 * Before fixing the header, save old To:.
                 * We do this because elide above has sorted To: list, and
                 * we would like to save message in a file named by the first
                 * recipient the user has entered, not the one being the first
                 * after sorting happened.
                 */
                if ((nsto = malloc(sizeof(struct name))) == NULL)
                        err(1, "Out of memory");
                bcopy(hp->h_to, nsto, sizeof(struct name));
        }
        fixhead(hp, to);
        if ((mtf = infix(hp, mtf)) == NULL) {
                fprintf(stderr, ". . . message lost, sorry.\n");
                return;
        }
        namelist = unpack(cat(hp->h_smopts, to));
        if (debug) {
                char **t;

                printf("Sendmail arguments:");
                for (t = namelist; *t != NULL; t++)
                        printf(" \"%s\"", *t);
                printf("\n");
                goto out;
        }
        if (value("recordrecip") != NULL) {
                /*
                 * Extract first recipient username from saved To: and use it
                 * as a filename.
                 */
                if ((nbuf = malloc(strlen(detract(nsto, 0)) + 1)) == NULL)
                        err(1, "Out of memory");
                if ((cp = yanklogin(detract(nsto, 0), nbuf)) != NULL)
                        (void)savemail(expand(nbuf), mtf);
                free(nbuf);
                free(nsto);
        } else if ((cp = value("record")) != NULL)
                (void)savemail(expand(cp), mtf);
        /*
         * Fork, set up the temporary mail file as standard
         * input for "mail", and exec with the user list we generated
         * far above.
         */
        pid = fork();
        if (pid == -1) {
                warn("fork");
                savedeadletter(mtf);
                goto out;
        }
        if (pid == 0) {
                sigset_t nset;
                (void)sigemptyset(&nset);
                (void)sigaddset(&nset, SIGHUP);
                (void)sigaddset(&nset, SIGINT);
                (void)sigaddset(&nset, SIGQUIT);
                (void)sigaddset(&nset, SIGTSTP);
                (void)sigaddset(&nset, SIGTTIN);
                (void)sigaddset(&nset, SIGTTOU);
                prepare_child(&nset, fileno(mtf), -1);
                if ((cp = value("sendmail")) != NULL)
                        cp = expand(cp);
                else
                        cp = _PATH_SENDMAIL;
                execv(cp, namelist);
                warn("%s", cp);
                _exit(1);
        }
        if (value("verbose") != NULL)
                (void)wait_child(pid);
        else
                free_child(pid);
out:
        (void)Fclose(mtf);
}

/*
 * Fix the header by glopping all of the expanded names from
 * the distribution list into the appropriate fields.
 */
void
fixhead(struct header *hp, struct name *tolist)
{
        struct name *np;

        hp->h_to = NULL;
        hp->h_cc = NULL;
        hp->h_bcc = NULL;
        for (np = tolist; np != NULL; np = np->n_flink) {
                /* Don't copy deleted addresses to the header */
                if (np->n_type & GDEL)
                        continue;
                if ((np->n_type & GMASK) == GTO)
                        hp->h_to =
                            cat(hp->h_to, nalloc(np->n_name, np->n_type));
                else if ((np->n_type & GMASK) == GCC)
                        hp->h_cc =
                            cat(hp->h_cc, nalloc(np->n_name, np->n_type));
                else if ((np->n_type & GMASK) == GBCC)
                        hp->h_bcc =
                            cat(hp->h_bcc, nalloc(np->n_name, np->n_type));
        }
}

/*
 * Prepend a header in front of the collected stuff
 * and return the new file.
 */
FILE *
infix(struct header *hp, FILE *fi)
{
        FILE *nfo, *nfi;
        int c, fd;
        char tempname[PATHSIZE];

        (void)snprintf(tempname, sizeof(tempname),
            "%s/mail.RsXXXXXXXXXX", tmpdir);
        if ((fd = mkstemp(tempname)) == -1 ||
            (nfo = Fdopen(fd, "w")) == NULL) {
                warn("%s", tempname);
                return (fi);
        }
        if ((nfi = Fopen(tempname, "r")) == NULL) {
                warn("%s", tempname);
                (void)Fclose(nfo);
                (void)rm(tempname);
                return (fi);
        }
        (void)rm(tempname);
        (void)puthead(hp, nfo,
            GTO|GSUBJECT|GCC|GBCC|GREPLYTO|GINREPLYTO|GNL|GCOMMA);
        c = getc(fi);
        while (c != EOF) {
                (void)putc(c, nfo);
                c = getc(fi);
        }
        if (ferror(fi)) {
                warnx("read");
                rewind(fi);
                return (fi);
        }
        (void)fflush(nfo);
        if (ferror(nfo)) {
                warn("%s", tempname);
                (void)Fclose(nfo);
                (void)Fclose(nfi);
                rewind(fi);
                return (fi);
        }
        (void)Fclose(nfo);
        (void)Fclose(fi);
        rewind(nfi);
        return (nfi);
}

/*
 * Dump the to, subject, cc header on the
 * passed file buffer.
 */
int
puthead(struct header *hp, FILE *fo, int w)
{
        int gotcha;

        gotcha = 0;
        if (hp->h_to != NULL && w & GTO)
                fmt("To:", hp->h_to, fo, w&GCOMMA), gotcha++;
        if (hp->h_subject != NULL && w & GSUBJECT)
                fprintf(fo, "Subject: %s\n", hp->h_subject), gotcha++;
        if (hp->h_cc != NULL && w & GCC)
                fmt("Cc:", hp->h_cc, fo, w&GCOMMA), gotcha++;
        if (hp->h_bcc != NULL && w & GBCC)
                fmt("Bcc:", hp->h_bcc, fo, w&GCOMMA), gotcha++;
        if (hp->h_replyto != NULL && w & GREPLYTO)
                fprintf(fo, "Reply-To: %s\n", hp->h_replyto), gotcha++;
        if (hp->h_inreplyto != NULL && w & GINREPLYTO)
                fprintf(fo, "In-Reply-To: <%s>\n", hp->h_inreplyto), gotcha++;
        if (gotcha && w & GNL)
                (void)putc('\n', fo);
        return (0);
}

/*
 * Format the given header line to not exceed 72 characters.
 */
void
fmt(const char *str, struct name *np, FILE *fo, int comma)
{
        int col, len;

        comma = comma ? 1 : 0;
        col = strlen(str);
        if (col)
                fputs(str, fo);
        for (; np != NULL; np = np->n_flink) {
                if (np->n_flink == NULL)
                        comma = 0;
                len = strlen(np->n_name);
                col++;          /* for the space */
                if (col + len + comma > 72 && col > 4) {
                        fprintf(fo, "\n    ");
                        col = 4;
                } else
                        fprintf(fo, " ");
                fputs(np->n_name, fo);
                if (comma)
                        fprintf(fo, ",");
                col += len + comma;
        }
        fprintf(fo, "\n");
}

/*
 * Save the outgoing mail on the passed file.
 */

/*ARGSUSED*/
int
savemail(char name[], FILE *fi)
{
        FILE *fo;
        char buf[BUFSIZ];
        int i;
        time_t now;
        mode_t saved_umask;

        saved_umask = umask(077);
        fo = Fopen(name, "a");
        umask(saved_umask);

        if (fo == NULL) {
                warn("%s", name);
                return (-1);
        }
        (void)time(&now);
        fprintf(fo, "From %s %s", myname, ctime(&now));
        while ((i = fread(buf, 1, sizeof(buf), fi)) > 0)
                (void)fwrite(buf, 1, i, fo);
        fprintf(fo, "\n");
        (void)fflush(fo);
        if (ferror(fo))
                warn("%s", name);
        (void)Fclose(fo);
        rewind(fi);
        return (0);
}