elemental-ircd/ssld/ssld.c

/*
 *  ssld.c: The ircd-ratbox ssl/zlib helper daemon thingy
 *  Copyright (C) 2007 Aaron Sethman <androsyn@ratbox.org>
 *  Copyright (C) 2007 ircd-ratbox development team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
 *  USA
 *
 *  $Id$
 */


#include "stdinc.h"

#ifdef HAVE_LIBZ
#include <zlib.h>
#endif

#define MAXPASSFD 4
#ifndef READBUF_SIZE
#define READBUF_SIZE 16384
#endif

static void setup_signals(void);
static pid_t ppid;

static inline int32_t
buf_to_int32(char *buf)
{
    int32_t x;
    memcpy(&x, buf, sizeof(x));
    return x;
}

static inline void
int32_to_buf(char *buf, int32_t x)
{
    memcpy(buf, &x, sizeof(x));
    return;
}

static inline uint16_t
buf_to_uint16(char *buf)
{
    uint16_t x;
    memcpy(&x, buf, sizeof(x));
    return x;
}

static inline void
uint16_to_buf(char *buf, uint16_t x)
{
    memcpy(buf, &x, sizeof(x));
    return;
}


static char inbuf[READBUF_SIZE];
#ifdef HAVE_LIBZ
static char outbuf[READBUF_SIZE];
#endif

typedef struct _mod_ctl_buf {
    rb_dlink_node node;
    char *buf;
    size_t buflen;
    rb_fde_t *F[MAXPASSFD];
    int nfds;
} mod_ctl_buf_t;

typedef struct _mod_ctl {
    rb_dlink_node node;
    int cli_count;
    rb_fde_t *F;
    rb_fde_t *F_pipe;
    rb_dlink_list readq;
    rb_dlink_list writeq;
} mod_ctl_t;

static mod_ctl_t *mod_ctl;


#ifdef HAVE_LIBZ
typedef struct _zlib_stream {
    z_stream instream;
    z_stream outstream;
} zlib_stream_t;
#endif

typedef struct _conn {
    rb_dlink_node node;
    mod_ctl_t *ctl;
    rawbuf_head_t *modbuf_out;
    rawbuf_head_t *plainbuf_out;

    int32_t id;

    rb_fde_t *mod_fd;
    rb_fde_t *plain_fd;
    unsigned long long mod_out;
    unsigned long long mod_in;
    unsigned long long plain_in;
    unsigned long long plain_out;
    uint8_t flags;
    void *stream;
} conn_t;

#define FLAG_SSL	0x01
#define FLAG_ZIP	0x02
#define FLAG_CORK	0x04
#define FLAG_DEAD	0x08
#define FLAG_SSL_W_WANTS_R 0x10	/* output needs to wait until input possible */
#define FLAG_SSL_R_WANTS_W 0x20	/* input needs to wait until output possible */
#define FLAG_ZIPSSL	0x40

#define IsSSL(x) ((x)->flags & FLAG_SSL)
#define IsZip(x) ((x)->flags & FLAG_ZIP)
#define IsCork(x) ((x)->flags & FLAG_CORK)
#define IsDead(x) ((x)->flags & FLAG_DEAD)
#define IsSSLWWantsR(x) ((x)->flags & FLAG_SSL_W_WANTS_R)
#define IsSSLRWantsW(x) ((x)->flags & FLAG_SSL_R_WANTS_W)
#define IsZipSSL(x)	((x)->flags & FLAG_ZIPSSL)

#define SetSSL(x) ((x)->flags |= FLAG_SSL)
#define SetZip(x) ((x)->flags |= FLAG_ZIP)
#define SetCork(x) ((x)->flags |= FLAG_CORK)
#define SetDead(x) ((x)->flags |= FLAG_DEAD)
#define SetSSLWWantsR(x) ((x)->flags |= FLAG_SSL_W_WANTS_R)
#define SetSSLRWantsW(x) ((x)->flags |= FLAG_SSL_R_WANTS_W)
#define SetZipSSL(x)	((x)->flags |= FLAG_ZIPSSL)

#define ClearSSL(x) ((x)->flags &= ~FLAG_SSL)
#define ClearZip(x) ((x)->flags &= ~FLAG_ZIP)
#define ClearCork(x) ((x)->flags &= ~FLAG_CORK)
#define ClearDead(x) ((x)->flags &= ~FLAG_DEAD)
#define ClearSSLWWantsR(x) ((x)->flags &= ~FLAG_SSL_W_WANTS_R)
#define ClearSSLRWantsW(x) ((x)->flags &= ~FLAG_SSL_R_WANTS_W)
#define ClearZipSSL(x)	((x)->flags &= ~FLAG_ZIPSSL)

#define NO_WAIT 0x0
#define WAIT_PLAIN 0x1

#define HASH_WALK_SAFE(i, max, ptr, next, table) for(i = 0; i < max; i++) { RB_DLINK_FOREACH_SAFE(ptr, next, table[i].head)
#define HASH_WALK_END }
#define CONN_HASH_SIZE 2000
#define connid_hash(x)	(&connid_hash_table[(x % CONN_HASH_SIZE)])



static rb_dlink_list connid_hash_table[CONN_HASH_SIZE];
static rb_dlink_list dead_list;

static void conn_mod_read_cb(rb_fde_t *fd, void *data);
static void conn_mod_write_sendq(rb_fde_t *, void *data);
static void conn_plain_write_sendq(rb_fde_t *, void *data);
static void mod_write_ctl(rb_fde_t *, void *data);
static void conn_plain_read_cb(rb_fde_t *fd, void *data);
static void conn_plain_read_shutdown_cb(rb_fde_t *fd, void *data);
static void mod_cmd_write_queue(mod_ctl_t * ctl, const void *data, size_t len);
static const char *remote_closed = "Remote host closed the connection";
static int ssl_ok;
#ifdef HAVE_LIBZ
static int zlib_ok = 1;
#else
static int zlib_ok = 0;
#endif


#ifdef HAVE_LIBZ
static void *
ssld_alloc(void *unused, size_t count, size_t size)
{
    return rb_malloc(count * size);
}

static void
ssld_free(void *unused, void *ptr)
{
    rb_free(ptr);
}
#endif

static conn_t *
conn_find_by_id(int32_t id)
{
    rb_dlink_node *ptr;
    conn_t *conn;

    RB_DLINK_FOREACH(ptr, (connid_hash(id))->head) {
        conn = ptr->data;
        if(conn->id == id && !IsDead(conn))
            return conn;
    }
    return NULL;
}

static void
conn_add_id_hash(conn_t * conn, int32_t id)
{
    conn->id = id;
    rb_dlinkAdd(conn, &conn->node, connid_hash(id));
}

static void
free_conn(conn_t * conn)
{
    rb_free_rawbuffer(conn->modbuf_out);
    rb_free_rawbuffer(conn->plainbuf_out);
#ifdef HAVE_LIBZ
    if(IsZip(conn)) {
        zlib_stream_t *stream = conn->stream;
        inflateEnd(&stream->instream);
        deflateEnd(&stream->outstream);
    }
#endif
    rb_free(conn);
}

static void
clean_dead_conns(void *unused)
{
    conn_t *conn;
    rb_dlink_node *ptr, *next;
    RB_DLINK_FOREACH_SAFE(ptr, next, dead_list.head) {
        conn = ptr->data;
        free_conn(conn);
    }
    dead_list.tail = dead_list.head = NULL;
}


static void
close_conn(conn_t * conn, int wait_plain, const char *fmt, ...)
{
    va_list ap;
    char reason[128];	/* must always be under 250 bytes */
    char buf[256];
    int len;
    if(IsDead(conn))
        return;

    rb_rawbuf_flush(conn->modbuf_out, conn->mod_fd);
    rb_rawbuf_flush(conn->plainbuf_out, conn->plain_fd);
    rb_close(conn->mod_fd);
    SetDead(conn);

    if(conn->id >= 0 && !IsZipSSL(conn))
        rb_dlinkDelete(&conn->node, connid_hash(conn->id));

    if(!wait_plain || fmt == NULL) {
        rb_close(conn->plain_fd);
        rb_dlinkAdd(conn, &conn->node, &dead_list);
        return;
    }
    rb_setselect(conn->plain_fd, RB_SELECT_READ, conn_plain_read_shutdown_cb, conn);
    rb_setselect(conn->plain_fd, RB_SELECT_WRITE, NULL, NULL);
    va_start(ap, fmt);
    rb_vsnprintf(reason, sizeof(reason), fmt, ap);
    va_end(ap);

    buf[0] = 'D';
    int32_to_buf(&buf[1], conn->id);
    strcpy(&buf[5], reason);
    len = (strlen(reason) + 1) + 5;
    mod_cmd_write_queue(conn->ctl, buf, len);
}

static conn_t *
make_conn(mod_ctl_t * ctl, rb_fde_t *mod_fd, rb_fde_t *plain_fd)
{
    conn_t *conn = rb_malloc(sizeof(conn_t));
    conn->ctl = ctl;
    conn->modbuf_out = rb_new_rawbuffer();
    conn->plainbuf_out = rb_new_rawbuffer();
    conn->mod_fd = mod_fd;
    conn->plain_fd = plain_fd;
    conn->id = -1;
    conn->stream = NULL;
    rb_set_nb(mod_fd);
    rb_set_nb(plain_fd);
    return conn;
}

static void
check_handshake_flood(void *unused)
{
    conn_t *conn;
    rb_dlink_node *ptr, *next;
    unsigned int count;
    int i;
    HASH_WALK_SAFE(i, CONN_HASH_SIZE, ptr, next, connid_hash_table) {
        conn = ptr->data;
        if(!IsSSL(conn))
            continue;

        count = rb_ssl_handshake_count(conn->mod_fd);
        /* nothing needs to do this more than twice in ten seconds i don't think */
        if(count > 2)
            close_conn(conn, WAIT_PLAIN, "Handshake flooding");
        else
            rb_ssl_clear_handshake_count(conn->mod_fd);
    }
    HASH_WALK_END
}

static void
conn_mod_write_sendq(rb_fde_t *fd, void *data)
{
    conn_t *conn = data;
    const char *err;
    int retlen;
    if(IsDead(conn))
        return;

    if(IsSSLWWantsR(conn)) {
        ClearSSLWWantsR(conn);
        conn_mod_read_cb(conn->mod_fd, conn);
        if(IsDead(conn))
            return;
    }

    while((retlen = rb_rawbuf_flush(conn->modbuf_out, fd)) > 0)
        conn->mod_out += retlen;

    if(retlen == 0 || (retlen < 0 && !rb_ignore_errno(errno))) {
        if(retlen == 0)
            close_conn(conn, WAIT_PLAIN, "%s", remote_closed);
        if(IsSSL(conn) && retlen == RB_RW_SSL_ERROR)
            err = rb_get_ssl_strerror(conn->mod_fd);
        else
            err = strerror(errno);
        close_conn(conn, WAIT_PLAIN, "Write error: %s", err);
        return;
    }
    if(rb_rawbuf_length(conn->modbuf_out) > 0) {
        if(retlen != RB_RW_SSL_NEED_READ)
            rb_setselect(conn->mod_fd, RB_SELECT_WRITE, conn_mod_write_sendq, conn);
        else {
            rb_setselect(conn->mod_fd, RB_SELECT_READ, conn_mod_write_sendq, conn);
            rb_setselect(conn->mod_fd, RB_SELECT_WRITE, NULL, NULL);
            SetSSLWWantsR(conn);
        }
    } else
        rb_setselect(conn->mod_fd, RB_SELECT_WRITE, NULL, NULL);

    if(IsCork(conn) && rb_rawbuf_length(conn->modbuf_out) == 0) {
        ClearCork(conn);
        conn_plain_read_cb(conn->plain_fd, conn);
    }

}

static void
conn_mod_write(conn_t * conn, void *data, size_t len)
{
    if(IsDead(conn))	/* no point in queueing to a dead man */
        return;
    rb_rawbuf_append(conn->modbuf_out, data, len);
}

static void
conn_plain_write(conn_t * conn, void *data, size_t len)
{
    if(IsDead(conn))	/* again no point in queueing to dead men */
        return;
    rb_rawbuf_append(conn->plainbuf_out, data, len);
}

static void
mod_cmd_write_queue(mod_ctl_t * ctl, const void *data, size_t len)
{
    mod_ctl_buf_t *ctl_buf;
    ctl_buf = rb_malloc(sizeof(mod_ctl_buf_t));
    ctl_buf->buf = rb_malloc(len);
    ctl_buf->buflen = len;
    memcpy(ctl_buf->buf, data, len);
    ctl_buf->nfds = 0;
    rb_dlinkAddTail(ctl_buf, &ctl_buf->node, &ctl->writeq);
    mod_write_ctl(ctl->F, ctl);
}

#ifdef HAVE_LIBZ
static void
common_zlib_deflate(conn_t * conn, void *buf, size_t len)
{
    int ret, have;
    z_stream *outstream = &((zlib_stream_t *) conn->stream)->outstream;
    outstream->next_in = buf;
    outstream->avail_in = len;
    outstream->next_out = (Bytef *) outbuf;
    outstream->avail_out = sizeof(outbuf);

    ret = deflate(outstream, Z_SYNC_FLUSH);
    if(ret != Z_OK) {
        /* deflate error */
        close_conn(conn, WAIT_PLAIN, "Deflate failed: %s", zError(ret));
        return;
    }
    if(outstream->avail_out == 0) {
        /* avail_out empty */
        close_conn(conn, WAIT_PLAIN, "error compressing data, avail_out == 0");
        return;
    }
    if(outstream->avail_in != 0) {
        /* avail_in isn't empty... */
        close_conn(conn, WAIT_PLAIN, "error compressing data, avail_in != 0");
        return;
    }
    have = sizeof(outbuf) - outstream->avail_out;
    conn_mod_write(conn, outbuf, have);
}

static void
common_zlib_inflate(conn_t * conn, void *buf, size_t len)
{
    int ret, have = 0;
    ((zlib_stream_t *) conn->stream)->instream.next_in = buf;
    ((zlib_stream_t *) conn->stream)->instream.avail_in = len;
    ((zlib_stream_t *) conn->stream)->instream.next_out = (Bytef *) outbuf;
    ((zlib_stream_t *) conn->stream)->instream.avail_out = sizeof(outbuf);

    while(((zlib_stream_t *) conn->stream)->instream.avail_in) {
        ret = inflate(&((zlib_stream_t *) conn->stream)->instream, Z_NO_FLUSH);
        if(ret != Z_OK) {
            if(!strncmp("ERROR ", buf, 6)) {
                close_conn(conn, WAIT_PLAIN, "Received uncompressed ERROR");
                return;
            }
            close_conn(conn, WAIT_PLAIN, "Inflate failed: %s", zError(ret));
            return;
        }
        have = sizeof(outbuf) - ((zlib_stream_t *) conn->stream)->instream.avail_out;

        if(((zlib_stream_t *) conn->stream)->instream.avail_in) {
            conn_plain_write(conn, outbuf, have);
            have = 0;
            ((zlib_stream_t *) conn->stream)->instream.next_out = (Bytef *) outbuf;
            ((zlib_stream_t *) conn->stream)->instream.avail_out = sizeof(outbuf);
        }
    }
    if(have == 0)
        return;

    conn_plain_write(conn, outbuf, have);
}
#endif

static int
plain_check_cork(conn_t * conn)
{
    if(rb_rawbuf_length(conn->modbuf_out) >= 4096) {
        /* if we have over 4k pending outbound, don't read until
         * we've cleared the queue */
        SetCork(conn);
        rb_setselect(conn->plain_fd, RB_SELECT_READ, NULL, NULL);
        /* try to write */
        conn_mod_write_sendq(conn->mod_fd, conn);
        return 1;
    }
    return 0;
}


static void
conn_plain_read_cb(rb_fde_t *fd, void *data)
{
    conn_t *conn = data;
    int length = 0;
    if(conn == NULL)
        return;

    if(IsDead(conn))
        return;

    if(plain_check_cork(conn))
        return;

    while(1) {
        if(IsDead(conn))
            return;

        length = rb_read(conn->plain_fd, inbuf, sizeof(inbuf));

        if(length == 0 || (length < 0 && !rb_ignore_errno(errno))) {
            close_conn(conn, NO_WAIT, NULL);
            return;
        }

        if(length < 0) {
            rb_setselect(conn->plain_fd, RB_SELECT_READ, conn_plain_read_cb, conn);
            conn_mod_write_sendq(conn->mod_fd, conn);
            return;
        }
        conn->plain_in += length;

#ifdef HAVE_LIBZ
        if(IsZip(conn))
            common_zlib_deflate(conn, inbuf, length);
        else
#endif
            conn_mod_write(conn, inbuf, length);
        if(IsDead(conn))
            return;
        if(plain_check_cork(conn))
            return;
    }
}

static void
conn_plain_read_shutdown_cb(rb_fde_t *fd, void *data)
{
    conn_t *conn = data;
    int length = 0;

    if(conn == NULL)
        return;

    while(1) {
        length = rb_read(conn->plain_fd, inbuf, sizeof(inbuf));

        if(length == 0 || (length < 0 && !rb_ignore_errno(errno))) {
            rb_close(conn->plain_fd);
            rb_dlinkAdd(conn, &conn->node, &dead_list);
            return;
        }

        if(length < 0) {
            rb_setselect(conn->plain_fd, RB_SELECT_READ, conn_plain_read_shutdown_cb, conn);
            return;
        }
    }
}

static void
conn_mod_read_cb(rb_fde_t *fd, void *data)
{
    conn_t *conn = data;
    const char *err;
    int length;
    if(conn == NULL)
        return;
    if(IsDead(conn))
        return;

    if(IsSSLRWantsW(conn)) {
        ClearSSLRWantsW(conn);
        conn_mod_write_sendq(conn->mod_fd, conn);
        if(IsDead(conn))
            return;
    }

    while(1) {
        if(IsDead(conn))
            return;

        length = rb_read(conn->mod_fd, inbuf, sizeof(inbuf));

        if(length == 0 || (length < 0 && !rb_ignore_errno(errno))) {
            if(length == 0) {
                close_conn(conn, WAIT_PLAIN, "%s", remote_closed);
                return;
            }

            if(IsSSL(conn) && length == RB_RW_SSL_ERROR)
                err = rb_get_ssl_strerror(conn->mod_fd);
            else
                err = strerror(errno);
            close_conn(conn, WAIT_PLAIN, "Read error: %s", err);
            return;
        }
        if(length < 0) {
            if(length != RB_RW_SSL_NEED_WRITE)
                rb_setselect(conn->mod_fd, RB_SELECT_READ, conn_mod_read_cb, conn);
            else {
                rb_setselect(conn->mod_fd, RB_SELECT_READ, NULL, NULL);
                rb_setselect(conn->mod_fd, RB_SELECT_WRITE, conn_mod_read_cb, conn);
                SetSSLRWantsW(conn);
            }
            conn_plain_write_sendq(conn->plain_fd, conn);
            return;
        }
        conn->mod_in += length;
#ifdef HAVE_LIBZ
        if(IsZip(conn))
            common_zlib_inflate(conn, inbuf, length);
        else
#endif
            conn_plain_write(conn, inbuf, length);
    }
}

static void
conn_plain_write_sendq(rb_fde_t *fd, void *data)
{
    conn_t *conn = data;
    int retlen;

    if(IsDead(conn))
        return;

    while((retlen = rb_rawbuf_flush(conn->plainbuf_out, fd)) > 0) {
        conn->plain_out += retlen;
    }
    if(retlen == 0 || (retlen < 0 && !rb_ignore_errno(errno))) {
        close_conn(data, NO_WAIT, NULL);
        return;
    }


    if(rb_rawbuf_length(conn->plainbuf_out) > 0)
        rb_setselect(conn->plain_fd, RB_SELECT_WRITE, conn_plain_write_sendq, conn);
    else
        rb_setselect(conn->plain_fd, RB_SELECT_WRITE, NULL, NULL);
}

static int
maxconn(void)
{
#if defined(RLIMIT_NOFILE) && defined(HAVE_SYS_RESOURCE_H)
    struct rlimit limit;

    if(!getrlimit(RLIMIT_NOFILE, &limit)) {
        return limit.rlim_cur;
    }
#endif /* RLIMIT_FD_MAX */
    return MAXCONNECTIONS;
}

static void
ssl_process_accept_cb(rb_fde_t *F, int status, struct sockaddr *addr, rb_socklen_t len, void *data)
{
    conn_t *conn = data;
    char buf[5 + RB_SSL_CERTFP_LEN];

    if(status == RB_OK) {
        if(rb_get_ssl_certfp(F, &buf[5])) {
            buf[0] = 'F';
            int32_to_buf(&buf[1], conn->id);
            mod_cmd_write_queue(conn->ctl, buf, sizeof buf);
        }
        conn_mod_read_cb(conn->mod_fd, conn);
        conn_plain_read_cb(conn->plain_fd, conn);
        return;
    }
    /* ircd doesn't care about the reason for this */
    close_conn(conn, NO_WAIT, 0);
    return;
}

static void
ssl_process_connect_cb(rb_fde_t *F, int status, void *data)
{
    conn_t *conn = data;
    char buf[5 + RB_SSL_CERTFP_LEN];

    if(status == RB_OK) {
        if(rb_get_ssl_certfp(F, &buf[5])) {
            buf[0] = 'F';
            int32_to_buf(&buf[1], conn->id);
            mod_cmd_write_queue(conn->ctl, buf, sizeof buf);
        }
        conn_mod_read_cb(conn->mod_fd, conn);
        conn_plain_read_cb(conn->plain_fd, conn);
    } else if(status == RB_ERR_TIMEOUT)
        close_conn(conn, WAIT_PLAIN, "SSL handshake timed out");
    else if(status == RB_ERROR_SSL)
        close_conn(conn, WAIT_PLAIN, "%s", rb_get_ssl_strerror(conn->mod_fd));
    else
        close_conn(conn, WAIT_PLAIN, "SSL handshake failed");
}


static void
cleanup_bad_message(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    int i;

    /* XXX should log this somehow */
    for (i = 0; i < ctlb->nfds; i++)
        rb_close(ctlb->F[i]);
}

static void
ssl_process_accept(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    conn_t *conn;
    int32_t id;

    conn = make_conn(ctl, ctlb->F[0], ctlb->F[1]);

    id = buf_to_int32(&ctlb->buf[1]);

    if(id >= 0)
        conn_add_id_hash(conn, id);
    SetSSL(conn);

    if(rb_get_type(conn->mod_fd) & RB_FD_UNKNOWN) {

        rb_set_type(conn->mod_fd, RB_FD_SOCKET);
    }
    if(rb_get_type(conn->mod_fd) == RB_FD_UNKNOWN)
        rb_set_type(conn->plain_fd, RB_FD_SOCKET);

    rb_ssl_start_accepted(ctlb->F[0], ssl_process_accept_cb, conn, 10);
}

static void
ssl_process_connect(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    conn_t *conn;
    int32_t id;
    conn = make_conn(ctl, ctlb->F[0], ctlb->F[1]);

    id = buf_to_int32(&ctlb->buf[1]);

    if(id >= 0)
        conn_add_id_hash(conn, id);
    SetSSL(conn);

    if(rb_get_type(conn->mod_fd) == RB_FD_UNKNOWN)
        rb_set_type(conn->mod_fd, RB_FD_SOCKET);

    if(rb_get_type(conn->mod_fd) == RB_FD_UNKNOWN)
        rb_set_type(conn->plain_fd, RB_FD_SOCKET);


    rb_ssl_start_connected(ctlb->F[0], ssl_process_connect_cb, conn, 10);
}

static void
process_stats(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    char outstat[512];
    conn_t *conn;
    const char *odata;
    int32_t id;

    id = buf_to_int32(&ctlb->buf[1]);

    if(id < 0)
        return;

    odata = &ctlb->buf[5];
    conn = conn_find_by_id(id);

    if(conn == NULL)
        return;

    rb_snprintf(outstat, sizeof(outstat), "S %s %llu %llu %llu %llu", odata,
                conn->plain_out, conn->mod_in, conn->plain_in, conn->mod_out);
    conn->plain_out = 0;
    conn->plain_in = 0;
    conn->mod_in = 0;
    conn->mod_out = 0;
    mod_cmd_write_queue(ctl, outstat, strlen(outstat) + 1);	/* +1 is so we send the \0 as well */
}

static void
change_connid(mod_ctl_t *ctl, mod_ctl_buf_t *ctlb)
{
    int32_t id = buf_to_int32(&ctlb->buf[1]);
    int32_t newid = buf_to_int32(&ctlb->buf[5]);
    conn_t *conn = conn_find_by_id(id);
    if(conn->id >= 0)
        rb_dlinkDelete(&conn->node, connid_hash(conn->id));
    SetZipSSL(conn);
    conn->id = newid;
}

#ifdef HAVE_LIBZ
static void
zlib_process(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    uint8_t level;
    size_t recvqlen;
    size_t hdr = (sizeof(uint8_t) * 2) + sizeof(int32_t);
    void *recvq_start;
    z_stream *instream, *outstream;
    conn_t *conn;
    int32_t id;

    conn = make_conn(ctl, ctlb->F[0], ctlb->F[1]);
    if(rb_get_type(conn->mod_fd) == RB_FD_UNKNOWN)
        rb_set_type(conn->mod_fd, RB_FD_SOCKET);

    if(rb_get_type(conn->plain_fd) == RB_FD_UNKNOWN)
        rb_set_type(conn->plain_fd, RB_FD_SOCKET);

    id = buf_to_int32(&ctlb->buf[1]);
    conn_add_id_hash(conn, id);

    level = (uint8_t)ctlb->buf[5];

    recvqlen = ctlb->buflen - hdr;
    recvq_start = &ctlb->buf[6];

    SetZip(conn);
    conn->stream = rb_malloc(sizeof(zlib_stream_t));
    instream = &((zlib_stream_t *) conn->stream)->instream;
    outstream = &((zlib_stream_t *) conn->stream)->outstream;

    instream->total_in = 0;
    instream->total_out = 0;
    instream->zalloc = (alloc_func) ssld_alloc;
    instream->zfree = (free_func) ssld_free;
    instream->data_type = Z_ASCII;
    inflateInit(&((zlib_stream_t *) conn->stream)->instream);

    outstream->total_in = 0;
    outstream->total_out = 0;
    outstream->zalloc = (alloc_func) ssld_alloc;
    outstream->zfree = (free_func) ssld_free;
    outstream->data_type = Z_ASCII;

    if(level > 9)
        level = Z_DEFAULT_COMPRESSION;

    deflateInit(&((zlib_stream_t *) conn->stream)->outstream, level);
    if(recvqlen > 0)
        common_zlib_inflate(conn, recvq_start, recvqlen);

    conn_mod_read_cb(conn->mod_fd, conn);
    conn_plain_read_cb(conn->plain_fd, conn);
    return;

}
#endif

static void
init_prng(mod_ctl_t * ctl, mod_ctl_buf_t * ctl_buf)
{
    char *path;
    prng_seed_t seed_type;

    seed_type = (prng_seed_t) ctl_buf->buf[1];
    path = &ctl_buf->buf[2];
    rb_init_prng(path, seed_type);
}


static void
ssl_new_keys(mod_ctl_t * ctl, mod_ctl_buf_t * ctl_buf)
{
    char *buf;
    char *cert, *key, *dhparam;

    buf = &ctl_buf->buf[2];
    cert = buf;
    buf += strlen(cert) + 1;
    key = buf;
    buf += strlen(key) + 1;
    dhparam = buf;
    if(strlen(dhparam) == 0)
        dhparam = NULL;

    if(!rb_setup_ssl_server(cert, key, dhparam)) {
        const char *invalid = "I";
        mod_cmd_write_queue(ctl, invalid, strlen(invalid));
        return;
    }
}

static void
send_nossl_support(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    static const char *nossl_cmd = "N";
    conn_t *conn;
    int32_t id;

    if(ctlb != NULL) {
        conn = make_conn(ctl, ctlb->F[0], ctlb->F[1]);
        id = buf_to_int32(&ctlb->buf[1]);

        if(id >= 0)
            conn_add_id_hash(conn, id);
        close_conn(conn, WAIT_PLAIN, "libratbox reports no SSL/TLS support");
    }
    mod_cmd_write_queue(ctl, nossl_cmd, strlen(nossl_cmd));
}

static void
send_i_am_useless(mod_ctl_t * ctl)
{
    static const char *useless = "U";
    mod_cmd_write_queue(ctl, useless, strlen(useless));
}

static void
send_nozlib_support(mod_ctl_t * ctl, mod_ctl_buf_t * ctlb)
{
    static const char *nozlib_cmd = "z";
    conn_t *conn;
    int32_t id;
    if(ctlb != NULL) {
        conn = make_conn(ctl, ctlb->F[0], ctlb->F[1]);
        id = buf_to_int32(&ctlb->buf[1]);

        if(id >= 0)
            conn_add_id_hash(conn, id);
        close_conn(conn, WAIT_PLAIN, "libratbox reports no zlib support");
    }
    mod_cmd_write_queue(ctl, nozlib_cmd, strlen(nozlib_cmd));
}

static void
mod_process_cmd_recv(mod_ctl_t * ctl)
{
    rb_dlink_node *ptr, *next;
    mod_ctl_buf_t *ctl_buf;

    RB_DLINK_FOREACH_SAFE(ptr, next, ctl->readq.head) {
        ctl_buf = ptr->data;

        switch (*ctl_buf->buf) {
        case 'A': {
            if (ctl_buf->nfds != 2 || ctl_buf->buflen != 5) {
                cleanup_bad_message(ctl, ctl_buf);
                break;
            }

            if(!ssl_ok) {
                send_nossl_support(ctl, ctl_buf);
                break;
            }
            ssl_process_accept(ctl, ctl_buf);
            break;
        }
        case 'C': {
            if (ctl_buf->nfds != 2 || ctl_buf->buflen != 5) {
                cleanup_bad_message(ctl, ctl_buf);
                break;
            }

            if(!ssl_ok) {
                send_nossl_support(ctl, ctl_buf);
                break;
            }
            ssl_process_connect(ctl, ctl_buf);
            break;
        }

        case 'K': {
            if(!ssl_ok) {
                send_nossl_support(ctl, ctl_buf);
                break;
            }
            ssl_new_keys(ctl, ctl_buf);
            break;
        }
        case 'I':
            init_prng(ctl, ctl_buf);
            break;
        case 'S': {
            process_stats(ctl, ctl_buf);
            break;
        }
        case 'Y': {
            change_connid(ctl, ctl_buf);
            break;
        }

#ifdef HAVE_LIBZ
        case 'Z': {
            if (ctl_buf->nfds != 2 || ctl_buf->buflen < 6) {
                cleanup_bad_message(ctl, ctl_buf);
                break;
            }

            /* just zlib only */
            zlib_process(ctl, ctl_buf);
            break;
        }
#else

        case 'Z':
            send_nozlib_support(ctl, ctl_buf);
            break;

#endif
        default:
            break;
            /* Log unknown commands */
        }
        rb_dlinkDelete(ptr, &ctl->readq);
        rb_free(ctl_buf->buf);
        rb_free(ctl_buf);
    }

}



static void
mod_read_ctl(rb_fde_t *F, void *data)
{
    mod_ctl_buf_t *ctl_buf;
    mod_ctl_t *ctl = data;
    int retlen;
    int i;

    do {
        ctl_buf = rb_malloc(sizeof(mod_ctl_buf_t));
        ctl_buf->buf = rb_malloc(READBUF_SIZE);
        ctl_buf->buflen = READBUF_SIZE;
        retlen = rb_recv_fd_buf(ctl->F, ctl_buf->buf, ctl_buf->buflen, ctl_buf->F,
                                MAXPASSFD);
        if(retlen <= 0) {
            rb_free(ctl_buf->buf);
            rb_free(ctl_buf);
        } else {
            ctl_buf->buflen = retlen;
            rb_dlinkAddTail(ctl_buf, &ctl_buf->node, &ctl->readq);
            for (i = 0; i < MAXPASSFD && ctl_buf->F[i] != NULL; i++)
                ;
            ctl_buf->nfds = i;
        }
    } while(retlen > 0);

    if(retlen == 0 || (retlen < 0 && !rb_ignore_errno(errno)))
        exit(0);

    mod_process_cmd_recv(ctl);
    rb_setselect(ctl->F, RB_SELECT_READ, mod_read_ctl, ctl);
}

static void
mod_write_ctl(rb_fde_t *F, void *data)
{
    mod_ctl_t *ctl = data;
    mod_ctl_buf_t *ctl_buf;
    rb_dlink_node *ptr, *next;
    int retlen, x;

    RB_DLINK_FOREACH_SAFE(ptr, next, ctl->writeq.head) {
        ctl_buf = ptr->data;
        retlen = rb_send_fd_buf(ctl->F, ctl_buf->F, ctl_buf->nfds, ctl_buf->buf,
                                ctl_buf->buflen, ppid);
        if(retlen > 0) {
            rb_dlinkDelete(ptr, &ctl->writeq);
            for(x = 0; x < ctl_buf->nfds; x++)
                rb_close(ctl_buf->F[x]);
            rb_free(ctl_buf->buf);
            rb_free(ctl_buf);

        }
        if(retlen == 0 || (retlen < 0 && !rb_ignore_errno(errno)))
            exit(0);

    }
    if(rb_dlink_list_length(&ctl->writeq) > 0)
        rb_setselect(ctl->F, RB_SELECT_WRITE, mod_write_ctl, ctl);
}


static void
read_pipe_ctl(rb_fde_t *F, void *data)
{
    int retlen;
    while((retlen = rb_read(F, inbuf, sizeof(inbuf))) > 0) {
        ;;		/* we don't do anything with the pipe really, just care if the other process dies.. */
    }
    if(retlen == 0 || (retlen < 0 && !rb_ignore_errno(errno)))
        exit(0);
    rb_setselect(F, RB_SELECT_READ, read_pipe_ctl, NULL);

}

int
main(int argc, char **argv)
{
    const char *s_ctlfd, *s_pipe, *s_pid;
    int ctlfd, pipefd, x, maxfd;
    maxfd = maxconn();

    s_ctlfd = getenv("CTL_FD");
    s_pipe = getenv("CTL_PIPE");
    s_pid = getenv("CTL_PPID");

    if(s_ctlfd == NULL || s_pipe == NULL || s_pid == NULL) {
        fprintf(stderr,
                "This is ircd-ratbox ssld.  You know you aren't supposed to run me directly?\n");
        fprintf(stderr,
                "You get an Id tag for this: $Id$\n");
        fprintf(stderr, "Have a nice life\n");
        exit(1);
    }

    ctlfd = atoi(s_ctlfd);
    pipefd = atoi(s_pipe);
    ppid = atoi(s_pid);
    x = 0;
#ifndef _WIN32
    for(x = 0; x < maxfd; x++) {
        if(x != ctlfd && x != pipefd && x > 2)
            close(x);
    }
    x = open("/dev/null", O_RDWR);

    if(x >= 0) {
        if(ctlfd != 0 && pipefd != 0)
            dup2(x, 0);
        if(ctlfd != 1 && pipefd != 1)
            dup2(x, 1);
        if(ctlfd != 2 && pipefd != 2)
            dup2(x, 2);
        if(x > 2)
            close(x);
    }
#endif
    setup_signals();
    rb_lib_init(NULL, NULL, NULL, 0, maxfd, 1024, 4096);
    rb_init_rawbuffers(1024);
    ssl_ok = rb_supports_ssl();
    mod_ctl = rb_malloc(sizeof(mod_ctl_t));
    mod_ctl->F = rb_open(ctlfd, RB_FD_SOCKET, "ircd control socket");
    mod_ctl->F_pipe = rb_open(pipefd, RB_FD_PIPE, "ircd pipe");
    rb_set_nb(mod_ctl->F);
    rb_set_nb(mod_ctl->F_pipe);
    rb_event_addish("clean_dead_conns", clean_dead_conns, NULL, 10);
    rb_event_add("check_handshake_flood", check_handshake_flood, NULL, 10);
    read_pipe_ctl(mod_ctl->F_pipe, NULL);
    mod_read_ctl(mod_ctl->F, mod_ctl);
    if(!zlib_ok && !ssl_ok) {
        /* this is really useless... */
        send_i_am_useless(mod_ctl);
        /* sleep until the ircd kills us */
        rb_sleep(2 << 30, 0);
        exit(1);
    }

    if(!zlib_ok)
        send_nozlib_support(mod_ctl, NULL);
    if(!ssl_ok)
        send_nossl_support(mod_ctl, NULL);
    rb_lib_loop(0);
    return 0;
}


#ifndef _WIN32
static void
dummy_handler(int sig)
{
    return;
}
#endif

static void
setup_signals()
{
#ifndef _WIN32
    struct sigaction act;

    act.sa_flags = 0;
    act.sa_handler = SIG_IGN;
    sigemptyset(&act.sa_mask);
    sigaddset(&act.sa_mask, SIGPIPE);
    sigaddset(&act.sa_mask, SIGALRM);
#ifdef SIGTRAP
    sigaddset(&act.sa_mask, SIGTRAP);
#endif

#ifdef SIGWINCH
    sigaddset(&act.sa_mask, SIGWINCH);
    sigaction(SIGWINCH, &act, 0);
#endif
    sigaction(SIGPIPE, &act, 0);
#ifdef SIGTRAP
    sigaction(SIGTRAP, &act, 0);
#endif

    act.sa_handler = dummy_handler;
    sigaction(SIGALRM, &act, 0);
#endif
}