/* notify.c -- Module to notify of new mail
 *
 * Copyright (c) 1994-2008 Carnegie Mellon University.  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. The name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any legal
 *    details, please contact
 *      Carnegie Mellon University
 *      Center for Technology Transfer and Enterprise Creation
 *      4615 Forbes Avenue
 *      Suite 302
 *      Pittsburgh, PA  15213
 *      (412) 268-7393, fax: (412) 268-7395
 *      innovation@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/un.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include "append.h"
#include "global.h"
#include "notify.h"
#include "xstrlcpy.h"
#include "xstrlcat.h"
#include "mailbox.h"
#include "util.h"
#include "times.h"

/* generated headers are not necessarily in current directory */
#include "imap/imap_err.h"

#define FNAME_NOTIFY_SOCK "/socket/notify"

static int add_arg(char *buf, int max_size, const char *arg, int *buflen)
{
    const char *myarg = (arg ? arg : "");
    int len = strlen(myarg) + 1;

    if (*buflen + len > max_size) return -1;

    strcat(buf+*buflen, myarg);
    *buflen += len;

    return 0;
}

static void notify_dlist(const char *sockpath, const char *method,
                         const char *class, const char *priority,
                         const char *user, const char *mailbox,
                         int nopt, const char **options,
                         const char *message, const char *fname,
                         const char *loginfo)
{
    struct sockaddr_un sun_data;
    struct protstream *in = NULL, *out = NULL;
    struct dlist *dl = dlist_newkvlist(NULL, "NOTIFY");
    struct dlist *res = NULL;
    struct dlist *il;
    int c;
    int soc = -1;
    int i;

    dlist_setatom(dl, "METHOD", method);
    dlist_setatom(dl, "CLASS", class);
    dlist_setatom(dl, "PRIORITY", priority);
    dlist_setatom(dl, "USER", user);
    dlist_setatom(dl, "MAILBOX", mailbox);
    il = dlist_newlist(dl, "OPTIONS");
    for (i = 0; i < nopt; i++)
        dlist_setatom(il, NULL, options[i]);
    dlist_setatom(dl, "MESSAGE", message);
    dlist_setatom(dl, "FILEPATH", fname);

    memset((char *)&sun_data, 0, sizeof(sun_data));
    sun_data.sun_family = AF_UNIX;
    strlcpy(sun_data.sun_path, sockpath, sizeof(sun_data.sun_path));

    soc = socket(PF_UNIX, SOCK_STREAM, 0);
    if (soc < 0) {
        syslog(LOG_ERR,
               "NOTIFY(%s): unable to create notify socket(): %m", loginfo);
        goto out;
    }

    if (connect(soc, (struct sockaddr *)&sun_data, sizeof(sun_data)) < 0) {
        syslog(LOG_ERR,
               "NOTIFY(%s): failed to connect to %s: %m", loginfo, sockpath);
        goto out;
    }

    in = prot_new(soc, 0);
    out = prot_new(soc, 1);
    /* Force use of LITERAL+ */
    prot_setisclient(in, 1);
    prot_setisclient(out, 1);

    dlist_print(dl, 1, out);
    prot_printf(out, "\r\n");
    prot_flush(out);

    c = dlist_parse(&res, 1, 0, 0, in);
    if (c == '\r') c = prot_getc(in);
    /* XXX - do something with the response?  Like have NOTIFY answer */
    if (c == '\n' && res && res->name) {
        if (strcmp(res->name, "OK")) {
            syslog(LOG_NOTICE, "NOTIFY(%s): response %s to method %s",
                  loginfo, res->name, method);
        }
    }
    else {
        syslog(LOG_ERR, "NOTIFY(%s): error sending %s to %s",
               loginfo, method, sockpath);
    }

out:
    if (in) prot_free(in);
    if (out) prot_free(out);
    if (soc >= 0) close(soc);
    dlist_free(&dl);
    dlist_free(&res);
}

EXPORTED void notify(const char *method,
            const char *class, const char *priority,
            const char *user, const char *mailbox,
            int nopt, const char **options,
            const char *message, const char *fname)
{
    const char *notify_sock = config_getstring(IMAPOPT_NOTIFYSOCKET);
    int soc = -1;
    struct sockaddr_un sun_data;
    char buf[NOTIFY_MAXSIZE] = "", noptstr[20];
    int buflen = 0;
    int i, r = 0;
    unsigned bufsiz;
    socklen_t optlen;
    struct buf logbuf = BUF_INITIALIZER;
    char *loginfo = NULL;

    buf_setcstr(&logbuf, class);
    if (user) {
        buf_printf(&logbuf, ", %s", user);
        if (mailbox) {
            buf_printf(&logbuf, ", %s", mailbox);
        }
    }
    loginfo = buf_release(&logbuf);

    if (!strncmp(notify_sock, "dlist:", 6)) {
        notify_dlist(notify_sock+6, method, class, priority,
                     user, mailbox, nopt, options,
                     message, fname, loginfo);
        free(loginfo);
        return;
    }

    soc = socket(AF_UNIX, SOCK_DGRAM, 0);
    if (soc == -1) {
        syslog(LOG_ERR,
               "NOTIFY(%s): unable to create notify socket(): %m", loginfo);
        goto out;
    }

    memset((char *)&sun_data, 0, sizeof(sun_data));
    sun_data.sun_family = AF_UNIX;
    if (notify_sock) {
        strlcpy(sun_data.sun_path, notify_sock, sizeof(sun_data.sun_path));
    }
    else {
        strlcpy(sun_data.sun_path, config_dir, sizeof(sun_data.sun_path));
        strlcat(sun_data.sun_path,
                FNAME_NOTIFY_SOCK, sizeof(sun_data.sun_path));
    }

    /* Get send buffer size */
    optlen = sizeof(bufsiz);
    r = getsockopt(soc, SOL_SOCKET, SO_SNDBUF, &bufsiz, &optlen);
    if (r == -1) {
        syslog(LOG_ERR,
               "NOTIFY(%s): unable to getsockopt(SO_SNDBUF) on socket: %m",
               loginfo);
        goto out;
    }

    /* Use minimum of 1/10 of send buffer size (-overhead) NOTIFY_MAXSIZE */
    bufsiz = MIN(bufsiz / 10 - 32, NOTIFY_MAXSIZE);

    /*
     * build request of the form:
     *
     * method NUL class NUL priority NUL user NUL mailbox NUL
     *   nopt NUL N(option NUL) message NUL
     */

    r = add_arg(buf, bufsiz, method, &buflen);
    if (!r) r = add_arg(buf, bufsiz, class, &buflen);
    if (!r) r = add_arg(buf, bufsiz, priority, &buflen);
    if (!r) r = add_arg(buf, bufsiz, user, &buflen);
    if (!r) r = add_arg(buf, bufsiz, mailbox, &buflen);

    snprintf(noptstr, sizeof(noptstr), "%d", nopt);
    if (!r) r = add_arg(buf, bufsiz, noptstr, &buflen);

    for (i = 0; !r && i < nopt; i++) {
        r = add_arg(buf, bufsiz, options[i], &buflen);
    }

    if (!r) r = add_arg(buf, bufsiz, message, &buflen);
    if (!r && fname) r = add_arg(buf, bufsiz, fname, &buflen);

    if (r) {
        syslog(LOG_ERR, "NOTIFY(%s): datagram too large", loginfo);
        goto out;
    }

    r = sendto(soc, buf, buflen, 0,
               (struct sockaddr *)&sun_data, sizeof(sun_data));

    if (r < 0) {
        syslog(LOG_ERR, "NOTIFY(%s): unable to sendto() socket: %m", loginfo);
        goto out;
    }
    if (r < buflen) {
        syslog(LOG_ERR, "NOTIFY(%s): short write to socket", loginfo);
        goto out;
    }

out:
    xclose(soc);
    free(loginfo);
}
