expand(),file_expand(): use a shared implementation..

[s-mailx.git] / fio.c

/*
 * S-nail - a mail user agent derived from Berkeley Mail.
 *
 * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
 * Copyright (c) 2012 Steffen "Daode" Nurpmeso.
 */
/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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 <sys/stat.h>
#include <sys/file.h>
#include <sys/wait.h>
#ifdef  HAVE_WORDEXP
#include <wordexp.h>
#endif  /* HAVE_WORDEXP */
#include <unistd.h>

#if defined (USE_NSS)
#include <nss.h>
#include <ssl.h>
#elif defined (USE_OPENSSL)
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/x509v3.h>
#include <openssl/x509.h>
#include <openssl/rand.h>
#endif  /* USE_SSL */
#ifdef  HAVE_SOCKETS
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#ifdef  HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif  /* HAVE_ARPA_INET_H */
#endif  /* HAVE_SOCKETS */

#include <errno.h>
#include "extern.h"

/*
 * Mail -- a mail program
 *
 * File I/O.
 */

/*
 * Evaluate the string given as a new mailbox name.
 * Supported meta characters:
 *      %       for my system mail box
 *      %user   for user's system mail box
 *      #       for previous file
 *      &       invoker's mbox file
 *      +file   file in folder directory
 *      any shell meta character
 * Return the file name as a dynamic string.
 */
static char *   _expand(char const *name, int only_local);
/* Perform shell meta character expansion */
static char *   _globname(char const *name);

static void makemessage(void);
static void append(struct message *mp);
static size_t length_of_line(const char *line, size_t linesize);
static char *fgetline_byone(char **line, size_t *linesize, size_t *llen,
                FILE *fp, int appendnl, size_t n);
static enum okay get_header(struct message *mp);

static char *
_expand(char const *name, int only_local)
{
        char cbuf[PATHSIZE], *res;
        struct str s;
        struct shortcut *sh;
        int dyn;

        /*
         * The order of evaluation is "%" and "#" expand into constants.
         * "&" can expand into "+".  "+" can expand into shell meta characters.
         * Shell meta characters expand into constants.
         * This way, we make no recursive expansion.
         */
        res = (char*)name;
        if ((sh = get_shortcut(res)) != NULL)
                res = sh->sh_long;

next:   dyn = 0;
        switch (*res) {
        case '%':
                if (res[1] == ':' && res[2]) {
                        res = &res[2];
                        goto next;
                }
                findmail((res[1] ? res + 1 : myname),
                        (res[1] != '\0' || uflag), cbuf, sizeof cbuf);
                res = cbuf;
                goto jleave;
        case '#':
                if (res[1] != 0)
                        break;
                if (prevfile[0] == 0) {
                        fprintf(stderr, tr(80, "No previous file\n"));
                        res = NULL;
                } else
                        res = prevfile;
                goto jleave;
        case '&':
                if (res[1] == 0 && (res = value("MBOX")) == NULL)
                        res = "~/mbox";
                break;
        }

        if (res[0] == '@' && which_protocol(mailname) == PROTO_IMAP) {
                res = str_concat_csvl(&s,
                        protbase(mailname), "/", res + 1, NULL)->s;
                dyn = 1;
        }

        if (res[0] == '+' && getfold(cbuf, sizeof cbuf) >= 0) {
                res = str_concat_csvl(&s,
                        cbuf, ((which_protocol(cbuf) == PROTO_IMAP &&
                                        strcmp(cbuf, protbase(cbuf))) /* XXX */
                                ? "" : "/"),
                        res + 1, NULL)->s;
                dyn = 1;
                if (cbuf[0] == '%' && cbuf[1] == ':')
                        goto next;
        }

        /* Catch the most common shell meta character */
        if (res[0] == '~' && (res[1] == '/' || res[1] == '\0')) {
                res = str_concat_csvl(&s, homedir, res + 1, NULL)->s;
                dyn = 1;
        }

        if (anyof(res, "|&;<>~{}()[]*?$`'\"\\") &&
                        which_protocol(res) == PROTO_FILE) {
                res = _globname(res);
                dyn = 1;
                goto jleave;
        }

        if (only_local)
                switch (which_protocol(res)) {
                case PROTO_FILE:
                case PROTO_MAILDIR:     /* XXX Really? ok MAILDIR for local? */
                        break;
                default:
                        fprintf(stderr, tr(280,
                                "\"%s\": only a local file or directory may "
                                "be used\n"), name);
                        res = NULL;
                        break;
                }

jleave:
        if (res && ! dyn)
                res = savestr(res);
        return (res);
}

static char *
_globname(char const *name)
{
#ifdef HAVE_WORDEXP
        wordexp_t we;
        char *cp;
        sigset_t nset;
        int i;

        /*
         * Some systems (notably Open UNIX 8.0.0) fork a shell for
         * wordexp() and wait for it; waiting will fail if our SIGCHLD
         * handler is active.
         */
        sigemptyset(&nset);
        sigaddset(&nset, SIGCHLD);
        sigprocmask(SIG_BLOCK, &nset, NULL);
        i = wordexp(name, &we, 0);
        sigprocmask(SIG_UNBLOCK, &nset, NULL);

        switch (i) {
        case 0:
                break;
        case WRDE_NOSPACE:
                fprintf(stderr, tr(83, "\"%s\": Expansion buffer overflow.\n"),
                        name);
                return NULL;
        case WRDE_BADCHAR:
        case WRDE_SYNTAX:
        default:
                fprintf(stderr, tr(242, "Syntax error in \"%s\"\n"), name);
                return NULL;
        }

        switch (we.we_wordc) {
        case 1:
                cp = savestr(we.we_wordv[0]);
                break;
        case 0:
                fprintf(stderr, tr(82, "\"%s\": No match.\n"), name);
                cp = NULL;
                break;
        default:
                fprintf(stderr, tr(84, "\"%s\": Ambiguous.\n"), name);
                cp = NULL;
        }

        wordfree(&we);
        return cp;

#else /* !HAVE_WORDEXP */
        char xname[PATHSIZE];
        char cmdbuf[PATHSIZE];          /* also used for file names */
        int pid, l;
        char *cp, *shell;
        int pivec[2];
        extern int wait_status;
        struct stat sbuf;

        if (pipe(pivec) < 0) {
                perror("pipe");
                return name;
        }
        snprintf(cmdbuf, sizeof cmdbuf, "echo %s", name);
        if ((shell = value("SHELL")) == NULL)
                shell = SHELL;
        pid = start_command(shell, 0, -1, pivec[1], "-c", cmdbuf, NULL);
        if (pid < 0) {
                close(pivec[0]);
                close(pivec[1]);
                return NULL;
        }
        close(pivec[1]);
again:
        l = read(pivec[0], xname, sizeof xname);
        if (l < 0) {
                if (errno == EINTR)
                        goto again;
                perror("read");
                close(pivec[0]);
                return NULL;
        }
        close(pivec[0]);
        if (wait_child(pid) < 0 && WTERMSIG(wait_status) != SIGPIPE) {
                fprintf(stderr, tr(81, "\"%s\": Expansion failed.\n"), name);
                return NULL;
        }
        if (l == 0) {
                fprintf(stderr, tr(82, "\"%s\": No match.\n"), name);
                return NULL;
        }
        if (l == sizeof xname) {
                fprintf(stderr, tr(83, "\"%s\": Expansion buffer overflow.\n"),
                        name);
                return NULL;
        }
        xname[l] = 0;
        for (cp = &xname[l-1]; *cp == '\n' && cp > xname; cp--)
                ;
        cp[1] = '\0';
        if (strchr(xname, ' ') && stat(xname, &sbuf) < 0) {
                fprintf(stderr, tr(84, "\"%s\": Ambiguous.\n"), name);
                return NULL;
        }
        return savestr(xname);
#endif /* !HAVE_WORDEXP */
}

/*
 * Set up the input pointers while copying the mail file into /tmp.
 */
void
setptr(FILE *ibuf, off_t offset)
{
        int c;
        size_t count;
        char *cp, *cp2;
        struct message this;
        int maybe, inhead, thiscnt;
        char *linebuf = NULL;
        size_t linesize = 0, filesize;

        maybe = 1;
        inhead = 0;
        thiscnt = 0;
        memset(&this, 0, sizeof this);
        this.m_flag = MUSED|MNEW|MNEWEST;
        filesize = mailsize - offset;
        offset = ftell(mb.mb_otf);
        for (;;) {
                if (fgetline(&linebuf, &linesize, &filesize, &count, ibuf, 0)
                                == NULL) {
                        this.m_xsize = this.m_size;
                        this.m_xlines = this.m_lines;
                        this.m_have = HAVE_HEADER|HAVE_BODY;
                        if (thiscnt > 0)
                                append(&this);
                        makemessage();
                        if (linebuf)
                                free(linebuf);
                        return;
                }
#ifdef  notdef
                if (linebuf[0] == '\0')
                        linebuf[0] = '.';
#endif
                fwrite(linebuf, sizeof *linebuf, count, mb.mb_otf);
                if (ferror(mb.mb_otf)) {
                        perror("/tmp");
                        exit(1);
                }
                if (linebuf[count - 1] == '\n')
                        linebuf[count - 1] = '\0';
                if (maybe && linebuf[0] == 'F' && is_head(linebuf, count)) {
                        this.m_xsize = this.m_size;
                        this.m_xlines = this.m_lines;
                        this.m_have = HAVE_HEADER|HAVE_BODY;
                        if (thiscnt++ > 0)
                                append(&this);
                        msgCount++;
                        this.m_flag = MUSED|MNEW|MNEWEST;
                        this.m_size = 0;
                        this.m_lines = 0;
                        this.m_block = mailx_blockof(offset);
                        this.m_offset = mailx_offsetof(offset);
                        inhead = 1;
                } else if (linebuf[0] == 0) {
                        inhead = 0;
                } else if (inhead) {
                        for (cp = linebuf, cp2 = "status";; cp++) {
                                if ((c = *cp2++) == 0) {
                                        while (c = *cp++, whitechar(c));
                                        if (cp[-1] != ':')
                                                break;
                                        while ((c = *cp++) != '\0')
                                                if (c == 'R')
                                                        this.m_flag |= MREAD;
                                                else if (c == 'O')
                                                        this.m_flag &= ~MNEW;
                                        break;
                                }
                                if (*cp != c && *cp != upperconv(c))
                                        break;
                        }
                        for (cp = linebuf, cp2 = "x-status";; cp++) {
                                if ((c = *cp2++) == 0) {
                                        while (c = *cp++, whitechar(c));
                                        if (cp[-1] != ':')
                                                break;
                                        while ((c = *cp++) != '\0')
                                                if (c == 'F')
                                                        this.m_flag |= MFLAGGED;
                                                else if (c == 'A')
                                                        this.m_flag|=MANSWERED;
                                                else if (c == 'T')
                                                        this.m_flag|=MDRAFTED;
                                        break;
                                }
                                if (*cp != c && *cp != upperconv(c))
                                        break;
                        }
                }
                offset += count;
                this.m_size += count;
                this.m_lines++;
                maybe = linebuf[0] == 0;
        }
        /*NOTREACHED*/
}

/*
 * Drop the passed line onto the passed output buffer.
 * If a write error occurs, return -1, else the count of
 * characters written, including the newline.
 */
int
putline(FILE *obuf, char *linebuf, size_t count)
{
        fwrite(linebuf, sizeof *linebuf, count, obuf);
        putc('\n', obuf);
        if (ferror(obuf))
                return (-1);
        return (count + 1);
}

/*
 * Read up a line from the specified input into the line
 * buffer.  Return the number of characters read.  Do not
 * include the newline at the end.
 *
 * n is the number of characters already read.
 */
int
readline_restart(FILE *ibuf, char **linebuf, size_t *linesize, size_t n)
{
        long sz;

        clearerr(ibuf);
        /*
         * Interrupts will cause trouble if we are inside a stdio call. As
         * this is only relevant if input comes from a terminal, we can simply
         * bypass it by read() then.
         */
        if (fileno(ibuf) == 0 && is_a_tty[0]) {
                if (*linebuf == NULL || *linesize < LINESIZE + n + 1)
                        *linebuf = srealloc(*linebuf,
                                        *linesize = LINESIZE + n + 1);
                for (;;) {
                        if (n >= *linesize - 128)
                                *linebuf = srealloc(*linebuf, *linesize += 256);
again:
                        sz = read(0, *linebuf + n, *linesize - n - 1);
                        if (sz > 0) {
                                n += sz;
                                (*linebuf)[n] = '\0';
                                if (n > 0 && (*linebuf)[n - 1] == '\n')
                                        break;
                        } else {
                                if (sz < 0 && errno == EINTR)
                                        goto again;
                                if (n > 0) {
                                        if ((*linebuf)[n - 1] != '\n') {
                                                (*linebuf)[n++] = '\n';
                                                (*linebuf)[n] = '\0';
                                        }
                                        break;
                                } else
                                        return -1;
                        }
                }
        } else {
                /*
                 * Not reading from standard input or standard input not
                 * a terminal. We read one char at a time as it is the
                 * only way to get lines with embedded NUL characters in
                 * standard stdio.
                 */
                if (fgetline_byone(linebuf, linesize, &n, ibuf, 1, n) == NULL)
                        return -1;
        }
        if (n > 0 && (*linebuf)[n - 1] == '\n')
                (*linebuf)[--n] = '\0';
        return n;
}

/*
 * Return a file buffer all ready to read up the
 * passed message pointer.
 */
FILE *
setinput(struct mailbox *mp, struct message *m, enum needspec need)
{
        enum okay ok = STOP;

        switch (need) {
        case NEED_HEADER:
                if (m->m_have & HAVE_HEADER)
                        ok = OKAY;
                else
                        ok = get_header(m);
                break;
        case NEED_BODY:
                if (m->m_have & HAVE_BODY)
                        ok = OKAY;
                else
                        ok = get_body(m);
                break;
        case NEED_UNSPEC:
                ok = OKAY;
                break;
        }
        if (ok != OKAY)
                return NULL;
        fflush(mp->mb_otf);
        if (fseek(mp->mb_itf, (long)mailx_positionof(m->m_block,
                                        m->m_offset), SEEK_SET) < 0) {
                perror("fseek");
                panic(catgets(catd, CATSET, 77, "temporary file seek"));
        }
        return (mp->mb_itf);
}

struct message *
setdot(struct message *mp)
{
        if (dot != mp) {
                prevdot = dot;
                did_print_dot = 0;
        }
        dot = mp;
        uncollapse1(dot, 0);
        return dot;
}

/*
 * Take the data out of the passed ghost file and toss it into
 * a dynamically allocated message structure.
 */
static void
makemessage(void)
{
        if (msgCount == 0)
                append(NULL);
        setdot(message);
        message[msgCount].m_size = 0;
        message[msgCount].m_lines = 0;
}

/*
 * Append the passed message descriptor onto the message structure.
 */
static void
append(struct message *mp)
{
        if (msgCount + 1 >= msgspace)
                message = srealloc(message, (msgspace += 64) * sizeof *message);
        if (msgCount > 0)
                message[msgCount - 1] = *mp;
}

/*
 * Delete a file, but only if the file is a plain file.
 */
int
rm(char *name)
{
        struct stat sb;

        if (stat(name, &sb) < 0)
                return(-1);
        if (!S_ISREG(sb.st_mode)) {
                errno = EISDIR;
                return(-1);
        }
        return(unlink(name));
}

static int sigdepth;            /* depth of holdsigs() */
static sigset_t nset, oset;
/*
 * Hold signals SIGHUP, SIGINT, and SIGQUIT.
 */
void
holdsigs(void)
{

        if (sigdepth++ == 0) {
                sigemptyset(&nset);
                sigaddset(&nset, SIGHUP);
                sigaddset(&nset, SIGINT);
                sigaddset(&nset, SIGQUIT);
                sigprocmask(SIG_BLOCK, &nset, &oset);
        }
}

/*
 * Release signals SIGHUP, SIGINT, and SIGQUIT.
 */
void
relsesigs(void)
{
        if (--sigdepth == 0)
                sigprocmask(SIG_SETMASK, &oset, (sigset_t *)NULL);
}

/*
 * Determine the size of the file possessed by
 * the passed buffer.
 */
off_t
fsize(FILE *iob)
{
        struct stat sbuf;

        if (fstat(fileno(iob), &sbuf) < 0)
                return 0;
        return sbuf.st_size;
}

/*
 * Just like expand(), but expanded file must be FILE or DIR
 */
char *
file_expand(char const *name)
{
        return (_expand(name, 1));
}

/*
 * Evaluate the string given as a new mailbox name.
 * Supported meta characters:
 *      %       for my system mail box
 *      %user   for user's system mail box
 *      #       for previous file
 *      &       invoker's mbox file
 *      +file   file in folder directory
 *      any shell meta character
 * Return the file name as a dynamic string.
 */
char *
expand(char const *name)
{
        return (_expand(name, 0));
}

/*
 * Determine the current folder directory name.
 */
int
getfold(char *name, int size)
{
        char *folder;
        enum protocol   p;

        if ((folder = value("folder")) == NULL)
                return (-1);
        if (*folder == '/' || ((p = which_protocol(folder)) != PROTO_FILE &&
                        p != PROTO_MAILDIR)) {
                strncpy(name, folder, size);
                name[size-1]='\0';
        } else {
                snprintf(name, size, "%s/%s", homedir, folder);
        }
        return (0);
}

/*
 * Return the name of the dead.letter file.
 */
char *
getdeadletter(void)
{
        char *cp;

        if ((cp = value("DEAD")) == NULL || (cp = file_expand(cp)) == NULL)
                cp = file_expand("~/dead.letter");
        else if (*cp != '/') {
                size_t sz = strlen(cp) + 3;
                char *buf = ac_alloc(sz);

                snprintf(buf, sz, "~/%s", cp);
                cp = file_expand(buf);
                ac_free(buf);
        }
        if (cp == NULL)
                cp = "dead.letter";
        return (cp);
}

/*
 * line is a buffer with the result of fgets(). Returns the first
 * newline or the last character read.
 */
static size_t
length_of_line(const char *line, size_t linesize)
{
        register size_t i;

        /*
         * Last character is always '\0' and was added by fgets.
         */
        linesize--;
        for (i = 0; i < linesize; i++)
                if (line[i] == '\n')
                        break;
        return i < linesize ? i + 1 : linesize;
}

/*
 * fgets replacement to handle lines of arbitrary size and with
 * embedded \0 characters.
 * line - line buffer. *line be NULL.
 * linesize - allocated size of line buffer.
 * count - maximum characters to read. May be NULL.
 * llen - length_of_line(*line).
 * fp - input FILE.
 * appendnl - always terminate line with \n, append if necessary.
 */
char *
fgetline(char **line, size_t *linesize, size_t *count, size_t *llen,
                FILE *fp, int appendnl)
{
        size_t i_llen, sz;

        if (count == NULL)
                /*
                 * If we have no count, we cannot determine where the
                 * characters returned by fgets() end if there was no
                 * newline. We have to read one character at one.
                 */
                return fgetline_byone(line, linesize, llen, fp, appendnl, 0);
        if (*line == NULL || *linesize < LINESIZE)
                *line = srealloc(*line, *linesize = LINESIZE);
        sz = *linesize <= *count ? *linesize : *count + 1;
        if (sz <= 1 || fgets(*line, sz, fp) == NULL)
                /*
                 * Leave llen untouched; it is used to determine whether
                 * the last line was \n-terminated in some callers.
                 */
                return NULL;
        i_llen = length_of_line(*line, sz);
        *count -= i_llen;
        while ((*line)[i_llen - 1] != '\n') {
                *line = srealloc(*line, *linesize += 256);
                sz = *linesize - i_llen;
                sz = (sz <= *count ? sz : *count + 1);
                if (sz <= 1 || fgets(&(*line)[i_llen], sz, fp) == NULL) {
                        if (appendnl) {
                                (*line)[i_llen++] = '\n';
                                (*line)[i_llen] = '\0';
                        }
                        break;
                }
                sz = length_of_line(&(*line)[i_llen], sz);
                i_llen += sz;
                *count -= sz;
        }
        if (llen)
                *llen = i_llen;
        return *line;
}

/*
 * Read a line, one character at once.
 */
static char *
fgetline_byone(char **line, size_t *linesize, size_t *llen,
                FILE *fp, int appendnl, size_t n)
{
        int c;

        if (*line == NULL || *linesize < LINESIZE + n + 1)
                *line = srealloc(*line, *linesize = LINESIZE + n + 1);
        for (;;) {
                if (n >= *linesize - 128)
                        *line = srealloc(*line, *linesize += 256);
                c = getc(fp);
                if (c != EOF) {
                        (*line)[n++] = c;
                        (*line)[n] = '\0';
                        if (c == '\n')
                                break;
                } else {
                        if (n > 0) {
                                if (appendnl) {
                                        (*line)[n++] = '\n';
                                        (*line)[n] = '\0';
                                }
                                break;
                        } else
                                return NULL;
                }
        }
        if (llen)
                *llen = n;
        return *line;
}

static enum okay
get_header(struct message *mp)
{
        switch (mb.mb_type) {
        case MB_FILE:
        case MB_MAILDIR:
                return OKAY;
        case MB_POP3:
                return pop3_header(mp);
        case MB_IMAP:
        case MB_CACHE:
                return imap_header(mp);
        case MB_VOID:
                return STOP;
        }
        /*NOTREACHED*/
        return STOP;
}

enum okay
get_body(struct message *mp)
{
        switch (mb.mb_type) {
        case MB_FILE:
        case MB_MAILDIR:
                return OKAY;
        case MB_POP3:
                return pop3_body(mp);
        case MB_IMAP:
        case MB_CACHE:
                return imap_body(mp);
        case MB_VOID:
                return STOP;
        }
        /*NOTREACHED*/
        return STOP;
}

#ifdef  HAVE_SOCKETS
static long xwrite(int fd, const char *data, size_t sz);

static long
xwrite(int fd, const char *data, size_t sz)
{
        long wo;
        size_t wt = 0;

        do {
                if ((wo = write(fd, data + wt, sz - wt)) < 0) {
                        if (errno == EINTR)
                                continue;
                        else
                                return -1;
                }
                wt += wo;
        } while (wt < sz);
        return sz;
}

int
sclose(struct sock *sp)
{
        int     i;

        if (sp->s_fd > 0) {
                if (sp->s_onclose != NULL)
                        (*sp->s_onclose)();
#if defined (USE_NSS)
                if (sp->s_use_ssl) {
                        sp->s_use_ssl = 0;
                        i = PR_Close(sp->s_prfd) == PR_SUCCESS ? 0 : -1;
                        sp->s_prfd = NULL;
                } else
#elif defined (USE_OPENSSL)
                if (sp->s_use_ssl) {
                        sp->s_use_ssl = 0;
                        SSL_shutdown(sp->s_ssl);
                        SSL_free(sp->s_ssl);
                        sp->s_ssl = NULL;
                        SSL_CTX_free(sp->s_ctx);
                        sp->s_ctx = NULL;
                }
#endif  /* USE_SSL */
                {
                        i = close(sp->s_fd);
                }
                sp->s_fd = -1;
                return i;
        }
        sp->s_fd = -1;
        return 0;
}

enum okay
swrite(struct sock *sp, const char *data)
{
        return swrite1(sp, data, strlen(data), 0);
}

enum okay
swrite1(struct sock *sp, const char *data, int sz, int use_buffer)
{
        int     x;

        if (use_buffer > 0) {
                int     di;
                enum okay       ok;

                if (sp->s_wbuf == NULL) {
                        sp->s_wbufsize = 4096;
                        sp->s_wbuf = smalloc(sp->s_wbufsize);
                        sp->s_wbufpos = 0;
                }
                while (sp->s_wbufpos + sz > sp->s_wbufsize) {
                        di = sp->s_wbufsize - sp->s_wbufpos;
                        sz -= di;
                        if (sp->s_wbufpos > 0) {
                                memcpy(&sp->s_wbuf[sp->s_wbufpos], data, di);
                                ok = swrite1(sp, sp->s_wbuf,
                                                sp->s_wbufsize, -1);
                        } else
                                ok = swrite1(sp, data,
                                                sp->s_wbufsize, -1);
                        if (ok != OKAY)
                                return STOP;
                        data += di;
                        sp->s_wbufpos = 0;
                }
                if (sz == sp->s_wbufsize) {
                        ok = swrite1(sp, data, sp->s_wbufsize, -1);
                        if (ok != OKAY)
                                return STOP;
                } else if (sz) {
                        memcpy(&sp->s_wbuf[sp->s_wbufpos], data, sz);
                        sp->s_wbufpos += sz;
                }
                return OKAY;
        } else if (use_buffer == 0 && sp->s_wbuf != NULL &&
                        sp->s_wbufpos > 0) {
                x = sp->s_wbufpos;
                sp->s_wbufpos = 0;
                if (swrite1(sp, sp->s_wbuf, x, -1) != OKAY)
                        return STOP;
        }
        if (sz == 0)
                return OKAY;
#if defined (USE_NSS)
        if (sp->s_use_ssl) {
                x = PR_Write(sp->s_prfd, data, sz);
        } else
#elif defined (USE_OPENSSL)
        if (sp->s_use_ssl) {
ssl_retry:      x = SSL_write(sp->s_ssl, data, sz);
                if (x < 0) {
                        switch (SSL_get_error(sp->s_ssl, x)) {
                        case SSL_ERROR_WANT_READ:
                        case SSL_ERROR_WANT_WRITE:
                                goto ssl_retry;
                        }
                }
        } else
#endif  /* USE_SSL */
        {
                x = xwrite(sp->s_fd, data, sz);
        }
        if (x != sz) {
                char    o[512];
                snprintf(o, sizeof o, "%s write error",
                                sp->s_desc ? sp->s_desc : "socket");
#if defined (USE_NSS)
                sp->s_use_ssl ? nss_gen_err("%s", o) : perror(o);
#elif defined (USE_OPENSSL)
                sp->s_use_ssl ? ssl_gen_err("%s", o) : perror(o);
#else   /* !USE_SSL */
                perror(o);
#endif  /* !USE_SSL */
                if (x < 0)
                        sclose(sp);
                return STOP;
        }
        return OKAY;
}

int
sgetline(char **line, size_t *linesize, size_t *linelen, struct sock *sp)
{
        char    *lp = *line;

        if (sp->s_rsz < 0) {
                sclose(sp);
                return sp->s_rsz;
        }
        do {
                if (*line == NULL || lp > &(*line)[*linesize - 128]) {
                        size_t diff = lp - *line;
                        *line = srealloc(*line, *linesize += 256);
                        lp = &(*line)[diff];
                }
                if (sp->s_rbufptr == NULL ||
                                sp->s_rbufptr >= &sp->s_rbuf[sp->s_rsz]) {
#if defined (USE_NSS)
                        if (sp->s_use_ssl) {
                                if ((sp->s_rsz = PR_Read(sp->s_prfd,
                                                sp->s_rbuf,
                                                sizeof sp->s_rbuf)) <= 0) {
                                        if (sp->s_rsz < 0) {
                                                char    o[512];
                                                snprintf(o, sizeof o, "%s",
                                                        sp->s_desc ?
                                                                sp->s_desc :
                                                                "socket");
                                                nss_gen_err("%s", o);
                                        }
                                        break;
                                }
                        } else
#elif defined (USE_OPENSSL)
                        if (sp->s_use_ssl) {
                ssl_retry:      if ((sp->s_rsz = SSL_read(sp->s_ssl,
                                                sp->s_rbuf,
                                                sizeof sp->s_rbuf)) <= 0) {
                                        if (sp->s_rsz < 0) {
                                                char    o[512];
                                                switch(SSL_get_error(sp->s_ssl,
                                                        sp->s_rsz)) {
                                                case SSL_ERROR_WANT_READ:
                                                case SSL_ERROR_WANT_WRITE:
                                                        goto ssl_retry;
                                                }
                                                snprintf(o, sizeof o, "%s",
                                                        sp->s_desc ?
                                                                sp->s_desc :
                                                                "socket");
                                                ssl_gen_err("%s", o);

                                        }
                                        break;
                                }
                        } else
#endif  /* USE_SSL */
                        {
                        again:  if ((sp->s_rsz = read(sp->s_fd, sp->s_rbuf,
                                                sizeof sp->s_rbuf)) <= 0) {
                                        if (sp->s_rsz < 0) {
                                                char    o[512];
                                                if (errno == EINTR)
                                                        goto again;
                                                snprintf(o, sizeof o, "%s",
                                                        sp->s_desc ?
                                                                sp->s_desc :
                                                                "socket");
                                                perror(o);
                                        }
                                        break;
                                }
                        }
                        sp->s_rbufptr = sp->s_rbuf;
                }
        } while ((*lp++ = *sp->s_rbufptr++) != '\n');
        *lp = '\0';
        if (linelen)
                *linelen = lp - *line;
        return lp - *line;
}

enum okay
sopen(const char *xserver, struct sock *sp, int use_ssl,
                const char *uhp, const char *portstr, int verbose)
{
#ifdef USE_IPV6
        char    hbuf[NI_MAXHOST];
        struct addrinfo hints, *res0, *res;
#else
        struct sockaddr_in      servaddr;
        struct in_addr  **pptr;
        struct hostent  *hp;
        struct servent  *ep;
        unsigned short  port = 0;
#endif
        int     sockfd;
        char    *cp;
        char    *server = (char *)xserver;
        (void)use_ssl;
        (void)uhp;

        if ((cp = strchr(server, ':')) != NULL) {
                portstr = &cp[1];
#ifndef USE_IPV6
                port = strtol(portstr, NULL, 10);
#endif
                server = salloc(cp - xserver + 1);
                memcpy(server, xserver, cp - xserver);
                server[cp - xserver] = '\0';
        }
#ifdef USE_IPV6
        memset(&hints, 0, sizeof hints);
        hints.ai_socktype = SOCK_STREAM;
        if (verbose)
                fprintf(stderr, "Resolving host %s . . .", server);
        if (getaddrinfo(server, portstr, &hints, &res0) != 0) {
                fprintf(stderr, catgets(catd, CATSET, 252,
                                "Could not resolve host: %s\n"), server);
                return STOP;
        } else if (verbose)
                fprintf(stderr, " done.\n");
        sockfd = -1;
        for (res = res0; res != NULL && sockfd < 0; res = res->ai_next) {
                if (verbose) {
                        if (getnameinfo(res->ai_addr, res->ai_addrlen,
                                                hbuf, sizeof hbuf, NULL, 0,
                                                NI_NUMERICHOST) != 0)
                                strcpy(hbuf, "unknown host");
                        fprintf(stderr, catgets(catd, CATSET, 192,
                                        "Connecting to %s:%s . . ."),
                                        hbuf, portstr);
                }
                if ((sockfd = socket(res->ai_family, res->ai_socktype,
                                res->ai_protocol)) >= 0) {
                        if (connect(sockfd, res->ai_addr, res->ai_addrlen)!=0) {
                                close(sockfd);
                                sockfd = -1;
                        }
                }
        }
        if (sockfd < 0) {
                perror(catgets(catd, CATSET, 254, "could not connect"));
                freeaddrinfo(res0);
                return STOP;
        }
        freeaddrinfo(res0);
#else /* USE_IPV6 */
        if (port == 0) {
                if (strcmp(portstr, "smtp") == 0)
                        port = htons(25);
                else if (strcmp(portstr, "smtps") == 0)
                        port = htons(465);
                else if (strcmp(portstr, "imap") == 0)
                        port = htons(143);
                else if (strcmp(portstr, "imaps") == 0)
                        port = htons(993);
                else if (strcmp(portstr, "pop3") == 0)
                        port = htons(110);
                else if (strcmp(portstr, "pop3s") == 0)
                        port = htons(995);
                else if ((ep = getservbyname((char *)portstr, "tcp")) != NULL)
                        port = ep->s_port;
                else {
                        fprintf(stderr, tr(251, "Unknown service: %s\n"),
                                portstr);
                        return STOP;
                }
        } else
                port = htons(port);
        if (verbose)
                fprintf(stderr, "Resolving host %s . . .", server);
        if ((hp = gethostbyname(server)) == NULL) {
                fprintf(stderr, catgets(catd, CATSET, 252,
                                "Could not resolve host: %s\n"), server);
                return STOP;
        } else if (verbose)
                fprintf(stderr, " done.\n");
        pptr = (struct in_addr **)hp->h_addr_list;
        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                perror(catgets(catd, CATSET, 253, "could not create socket"));
                return STOP;
        }
        memset(&servaddr, 0, sizeof servaddr);
        servaddr.sin_family = AF_INET;
        servaddr.sin_port = port;
        memcpy(&servaddr.sin_addr, *pptr, sizeof(struct in_addr));
        if (verbose)
                fprintf(stderr, catgets(catd, CATSET, 192,
                                "Connecting to %s:%d . . ."),
                                inet_ntoa(**pptr), ntohs(port));
        if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof servaddr)
                        != 0) {
                perror(catgets(catd, CATSET, 254, "could not connect"));
                return STOP;
        }
#endif /* USE_IPV6 */
        if (verbose)
                fputs(catgets(catd, CATSET, 193, " connected.\n"), stderr);
        memset(sp, 0, sizeof *sp);
        sp->s_fd = sockfd;
#ifdef USE_SSL
        if (use_ssl) {
                enum okay ok;

                if ((ok = ssl_open(server, sp, uhp)) != OKAY)
                        sclose(sp);
                return ok;
        }
#endif
        return OKAY;
}
#endif  /* HAVE_SOCKETS */