/*      $NetBSD: names.c,v 1.33 2017/11/09 20:27:50 christos Exp $      */

/*
 * 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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)names.c     8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: names.c,v 1.33 2017/11/09 20:27:50 christos Exp $");
#endif
#endif /* not lint */

/*
 * Mail -- a mail program
 *
 * Handle name lists.
 */

#include "rcv.h"
#include "extern.h"

/*
 * Allocate a single element of a name list,
 * initialize its name field to the passed
 * name and return it.
 */
PUBLIC struct name *
nalloc(char str[], int ntype)
{
        struct name *np;

        np = salloc(sizeof(*np));
        np->n_flink = NULL;
        np->n_blink = NULL;
        np->n_type = ntype;
        np->n_name = savestr(str);
        return np;
}

/*
 * Find the tail of a list and return it.
 */
static struct name *
tailof(struct name *name)
{
        struct name *np;

        np = name;
        if (np == NULL)
                return NULL;
        while (np->n_flink != NULL)
                np = np->n_flink;
        return np;
}

/*
 * Grab a single word (liberal word)
 * Throw away things between ()'s, and take anything between <>.
 */
static char *
yankword(char *ap, char wbuf[])
{
        char *cp, *cp2;

        cp = ap;
        for (;;) {
                if (*cp == '\0')
                        return NULL;
                if (*cp == '(') {
                        int nesting = 0;

                        while (*cp != '\0') {
                                switch (*cp++) {
                                case '(':
                                        nesting++;
                                        break;
                                case ')':
                                        --nesting;
                                        break;
                                }
                                if (nesting <= 0)
                                        break;
                        }
                } else if (is_WSP(*cp) || *cp == ',')
                        cp++;
                else
                        break;
        }
        if (*cp ==  '<')
                for (cp2 = wbuf; *cp && (*cp2++ = *cp++) != '>'; /*EMPTY*/)
                        continue;
        else
                for (cp2 = wbuf; *cp && !strchr(" \t,(", *cp); *cp2++ = *cp++)
                        continue;
        *cp2 = '\0';
        return cp;
}

/*
 * Extract a list of names from a line,
 * and make a list of names from it.
 * Return the list or NULL if none found.
 */
PUBLIC struct name *
extract(char line[], int ntype)
{
        char *cp;
        struct name *begin, *np, *t;
        char nbuf[LINESIZE];

        if (line == NULL || *line == '\0')
                return NULL;
        begin = NULL;
        np = NULL;
        cp = line;
        while ((cp = yankword(cp, nbuf)) != NULL) {
                t = nalloc(nbuf, ntype);
                if (begin == NULL)
                        begin = t;
                else
                        np->n_flink = t;
                t->n_blink = np;
                np = t;
        }
        return begin;
}

/* XXX - is this really sufficient? */
static int need_quotes(char *str)
{
        return strpbrk(str, " \t") != NULL;
}

/*
 * Turn a list of names into a string of the same names.
 */
PUBLIC char *
detract(struct name *np, int ntype)
{
        size_t s;
        char *cp, *begin;
        struct name *p;
        int comma;
        int quote;

        quote = ntype & GSMOPTS;
        comma = ntype & GCOMMA;
        if (np == NULL)
                return NULL;
        ntype &= ~GCOMMA;
        s = 0;
        if (debug && comma)
                (void)fprintf(stderr, "detract asked to insert commas\n");
        for (p = np; p != NULL; p = p->n_flink) {
                if (ntype && (p->n_type & GMASK) != ntype)
                        continue;
                s += strlen(p->n_name) + 1;
                if (comma)
                        s++;
                if (quote && need_quotes(p->n_name))
                        s += 2;
        }
        if (s == 0)
                return NULL;
        s += 2;
        begin = salloc(s);
        cp = begin;
        for (p = np; p != NULL; p = p->n_flink) {
                int do_quotes;
                if (ntype && (p->n_type & GMASK) != ntype)
                        continue;
                do_quotes = (quote && need_quotes(p->n_name));
                if (do_quotes)
                        *cp++ = '"';
                cp = copy(p->n_name, cp);
                if (comma && p->n_flink != NULL)
                        *cp++ = ',';
                if (do_quotes)
                        *cp++ = '"';
                *cp++ = ' ';
        }
        *--cp = 0;
        if (comma && *--cp == ',')
                *cp = 0;
        return begin;
}

/*
 * Determine if the passed address is a local "send to file" address.
 * If any of the network metacharacters precedes any slashes, it can't
 * be a filename.  We cheat with .'s to allow path names like ./...
 */
static int
isfileaddr(char *name)
{
        char *cp;

        if (*name == '+')
                return 1;
        for (cp = name; *cp; cp++) {
                if (*cp == '!' || *cp == '%' || *cp == '@')
                        return 0;
                if (*cp == '/')
                        return 1;
        }
        return 0;
}

/*
 * For each recipient in the passed name list with a /
 * in the name, append the message to the end of the named file
 * and remove him from the recipient list.
 *
 * Recipients whose name begins with | are piped through the given
 * program and removed.
 */
PUBLIC struct name *
outof(struct name *names, FILE *fo, struct header *hp)
{
        int c, fd;
        struct name *np, *begin;
        time_t now;
        char *date;
        const char *fname;
        FILE *fout, *fin;
        int ispipe;
        char tempname[PATHSIZE];

        if (value("expandaddr") == NULL)
                return names;

        begin = names;
        np = names;
        (void)time(&now);
        date = ctime(&now);
        while (np != NULL) {
                if (!isfileaddr(np->n_name) && np->n_name[0] != '|') {
                        np = np->n_flink;
                        continue;
                }
                ispipe = np->n_name[0] == '|';
                if (ispipe)
                        fname = np->n_name+1;
                else {
                        fname = expand(np->n_name);
                        if (fname == NULL) {
                                warnx("Filename expansion of %s failed",
                                    np->n_name);
                                senderr++;
                                goto cant;
                        }
                }


                /*
                 * See if we have copied the complete message out yet.
                 * If not, do so.
                 */

                if (image < 0) {
                        (void)snprintf(tempname, sizeof(tempname),
                            "%s/mail.ReXXXXXXXXXXXX", tmpdir);
                        if ((fd = mkstemp(tempname)) == -1 ||
                            (fout = Fdopen(fd, "aef")) == NULL) {
                                if (fd != -1)
                                        (void)close(fd);
                                warn("%s", tempname);
                                senderr++;
                                goto cant;
                        }
                        image = open(tempname, O_RDWR | O_CLOEXEC);
                        (void)unlink(tempname);
                        if (image < 0) {
                                warn("%s", tempname);
                                senderr++;
                                (void)Fclose(fout);
                                goto cant;
                        }
                        (void)fprintf(fout, "From %s %s", myname, date);
#ifdef MIME_SUPPORT
                        (void)puthead(hp, fout, GTO|GSUBJECT|GCC|GMISC|GMIME|GNL);
#else
                        (void)puthead(hp, fout, GTO|GSUBJECT|GCC|GMISC|GNL);
#endif
                        while ((c = getc(fo)) != EOF)
                                (void)putc(c, fout);
                        rewind(fo);
                        (void)putc('\n', fout);
                        (void)fflush(fout);
                        if (ferror(fout)) {
                                warn("%s", tempname);
                                senderr++;
                                (void)Fclose(fout);
                                goto cant;
                        }
                        (void)Fclose(fout);
                }

                /*
                 * Now either copy "image" to the desired file
                 * or give it as the standard input to the desired
                 * program as appropriate.
                 */

                if (ispipe) {
                        int pid;
                        const char *shellcmd;
                        sigset_t nset;

                        /*
                         * XXX
                         * We can't really reuse the same image file,
                         * because multiple piped recipients will
                         * share the same lseek location and trample
                         * on one another.
                         */
                        if ((shellcmd = value(ENAME_SHELL)) == NULL)
                                shellcmd = _PATH_CSHELL;
                        (void)sigemptyset(&nset);
                        (void)sigaddset(&nset, SIGHUP);
                        (void)sigaddset(&nset, SIGINT);
                        (void)sigaddset(&nset, SIGQUIT);
                        pid = start_command(shellcmd, &nset,
                                image, -1, "-c", fname, NULL);
                        if (pid < 0) {
                                senderr++;
                                goto cant;
                        }
                        free_child(pid);
                } else {
                        int f;
                        if ((fout = Fopen(fname, "aef")) == NULL) {
                                warn("%s", fname);
                                senderr++;
                                goto cant;
                        }
                        if ((f = dup(image)) < 0) {
                                warn("dup");
                                fin = NULL;
                        } else
                                fin = Fdopen(f, "ref");
                        if (fin == NULL) {
                                (void)fprintf(stderr, "Can't reopen image\n");
                                (void)Fclose(fout);
                                senderr++;
                                goto cant;
                        }
                        rewind(fin);
                        while ((c = getc(fin)) != EOF)
                                (void)putc(c, fout);
                        if (ferror(fout)) {
                                warn("%s", fname);
                                senderr++;
                                (void)Fclose(fout);
                                (void)Fclose(fin);
                                goto cant;
                        }
                        (void)Fclose(fout);
                        (void)Fclose(fin);
                }
cant:
                /*
                 * In days of old we removed the entry from the
                 * the list; now for sake of header expansion
                 * we leave it in and mark it as deleted.
                 */
                np->n_type |= GDEL;
                np = np->n_flink;
        }
        if (image >= 0) {
                (void)close(image);
                image = -1;
        }
        return begin;
}

/*
 * Put another node onto a list of names and return
 * the list.
 */
static struct name *
put(struct name *list, struct name *node)
{
        node->n_flink = list;
        node->n_blink = NULL;
        if (list != NULL)
                list->n_blink = node;
        return node;
}

/*
 * Recursively expand a group name.  We limit the expansion to some
 * fixed level to keep things from going haywire.
 * Direct recursion is not expanded for convenience.
 */
PUBLIC struct name *
gexpand(struct name *nlist, struct grouphead *gh, int metoo, int ntype)
{
        struct group *gp;
        struct grouphead *ngh;
        struct name *np;
        static int depth;
        char *cp;

        if (depth > MAXEXP) {
                (void)printf("Expanding alias to depth larger than %d\n", MAXEXP);
                return nlist;
        }
        depth++;
        for (gp = gh->g_list; gp != NULL; gp = gp->ge_link) {
                cp = gp->ge_name;
                if (*cp == '\\')
                        goto quote;
                if (strcmp(cp, gh->g_name) == 0)
                        goto quote;
                if ((ngh = findgroup(cp)) != NULL) {
                        nlist = gexpand(nlist, ngh, metoo, ntype);
                        continue;
                }
quote:
                np = nalloc(cp, ntype);
                /*
                 * At this point should allow to expand
                 * to self if only person in group
                 */
                if (gp == gh->g_list && gp->ge_link == NULL)
                        goto skip;
                if (!metoo && strcmp(cp, myname) == 0)
                        np->n_type |= GDEL;
skip:
                nlist = put(nlist, np);
        }
        depth--;
        return nlist;
}

/*
 * Map all of the aliased users in the invoker's mailrc
 * file and insert them into the list.
 * Changed after all these months of service to recursively
 * expand names (2/14/80).
 */

PUBLIC struct name *
usermap(struct name *names)
{
        struct name *new, *np, *cp;
        struct grouphead *gh;
        int metoo;

        new = NULL;
        np = names;
        metoo = (value(ENAME_METOO) != NULL);
        while (np != NULL) {
                if (np->n_name[0] == '\\') {
                        cp = np->n_flink;
                        new = put(new, np);
                        np = cp;
                        continue;
                }
                gh = findgroup(np->n_name);
                cp = np->n_flink;
                if (gh != NULL)
                        new = gexpand(new, gh, metoo, np->n_type);
                else
                        new = put(new, np);
                np = cp;
        }
        return new;
}

/*
 * Concatenate the two passed name lists, return the result.
 */
PUBLIC struct name *
cat(struct name *n1, struct name *n2)
{
        struct name *tail;

        if (n1 == NULL)
                return n2;
        if (n2 == NULL)
                return n1;
        tail = tailof(n1);
        tail->n_flink = n2;
        n2->n_blink = tail;
        return n1;
}

/*
 * Determine the number of undeleted elements in
 * a name list and return it.
 */
PUBLIC int
count(struct name *np)
{
        int c;

        for (c = 0; np != NULL; np = np->n_flink)
                if ((np->n_type & GDEL) == 0)
                        c++;
        return c;
}

/*
 * Unpack the name list onto a vector of strings.
 * Return an error if the name list won't fit.
 */
PUBLIC const char **
unpack(struct name *smopts, struct name *np)
{
        const char **ap, **begin;
        struct name *n;
        int t, extra, metoo, verbose;

        n = np;
        if ((t = count(n)) == 0)
                errx(EXIT_FAILURE, "No names to unpack");
        /*
         * Compute the number of extra arguments we will need.
         * We need at least two extra -- one for "mail" and one for
         * the terminating 0 pointer.  Additional spots may be needed
         * to pass along -f to the host mailer.
         */
        extra = 3 + count(smopts);
        extra++;
        metoo = value(ENAME_METOO) != NULL;
        if (metoo)
                extra++;
        verbose = value(ENAME_VERBOSE) != NULL;
        if (verbose)
                extra++;
        begin = salloc((t + extra) * sizeof(*begin));
        ap = begin;
        *ap++ = "sendmail";
        *ap++ = "-i";
        if (metoo)
                *ap++ = "-m";
        if (verbose)
                *ap++ = "-v";
        for (/*EMPTY*/; smopts != NULL; smopts = smopts->n_flink)
                if ((smopts->n_type & GDEL) == 0)
                        *ap++ = smopts->n_name;
        *ap++ = "--";
        for (/*EMPTY*/; n != NULL; n = n->n_flink)
                if ((n->n_type & GDEL) == 0)
                        *ap++ = n->n_name;
        *ap = NULL;
        return begin;
}

/*
 * Remove all of the duplicates from the passed name list by
 * insertion sorting them, then checking for dups.
 * Return the head of the new list.
 */
PUBLIC struct name *
elide(struct name *names)
{
        struct name *np, *t, *new;
        struct name *x;

        if (names == NULL)
                return NULL;
        new = names;
        np = names;
        np = np->n_flink;
        if (np != NULL)
                np->n_blink = NULL;
        new->n_flink = NULL;
        while (np != NULL) {
                t = new;
                while (strcasecmp(t->n_name, np->n_name) < 0) {
                        if (t->n_flink == NULL)
                                break;
                        t = t->n_flink;
                }

                /*
                 * If we ran out of t's, put the new entry after
                 * the current value of t.
                 */

                if (strcasecmp(t->n_name, np->n_name) < 0) {
                        t->n_flink = np;
                        np->n_blink = t;
                        t = np;
                        np = np->n_flink;
                        t->n_flink = NULL;
                        continue;
                }

                /*
                 * Otherwise, put the new entry in front of the
                 * current t.  If at the front of the list,
                 * the new guy becomes the new head of the list.
                 */

                if (t == new) {
                        t = np;
                        np = np->n_flink;
                        t->n_flink = new;
                        new->n_blink = t;
                        t->n_blink = NULL;
                        new = t;
                        continue;
                }

                /*
                 * The normal case -- we are inserting into the
                 * middle of the list.
                 */

                x = np;
                np = np->n_flink;
                x->n_flink = t;
                x->n_blink = t->n_blink;
                t->n_blink->n_flink = x;
                t->n_blink = x;
        }

        /*
         * Now the list headed up by new is sorted.
         * Go through it and remove duplicates.
         */

        np = new;
        while (np != NULL) {
                t = np;
                while (t->n_flink != NULL &&
                       strcasecmp(np->n_name, t->n_flink->n_name) == 0)
                        t = t->n_flink;
                if (t == np || t == NULL) {
                        np = np->n_flink;
                        continue;
                }

                /*
                 * Now t points to the last entry with the same name
                 * as np.  Make np point beyond t.
                 */

                np->n_flink = t->n_flink;
                if (t->n_flink != NULL)
                        t->n_flink->n_blink = np;
                np = np->n_flink;
        }
        return new;
}

/*
 * Delete the given name from a namelist.
 */
PUBLIC struct name *
delname(struct name *np, char name[])
{
        struct name *p;

        for (p = np; p != NULL; p = p->n_flink)
                if (strcasecmp(p->n_name, name) == 0) {
                        if (p->n_blink == NULL) {
                                if (p->n_flink != NULL)
                                        p->n_flink->n_blink = NULL;
                                np = p->n_flink;
                                continue;
                        }
                        if (p->n_flink == NULL) {
                                if (p->n_blink != NULL)
                                        p->n_blink->n_flink = NULL;
                                continue;
                        }
                        p->n_blink->n_flink = p->n_flink;
                        p->n_flink->n_blink = p->n_blink;
                }
        return np;
}

/*
 * Pretty print a name list
 * Uncomment it if you need it.
 */
#if 0
PUBLIC void
prettyprint(name)
        struct name *name;
{
        struct name *np;

        np = name;
        while (np != NULL) {
                (void)fprintf(stderr, "%s(%d) ", np->n_name, np->n_type);
                np = np->n_flink;
        }
        (void)fprintf(stderr, "\n");
}
#endif