sendmail/libmilter/engine.c

/*
 *  Copyright (c) 1999-2004, 2006-2008 Sendmail, Inc. and its suppliers.
 *  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#include <sm/gen.h>
SM_RCSID("@(#)$Id: engine.c,v 8.166 2009/11/06 00:57:07 ca Exp $")

#include "libmilter.h"

#if NETINET || NETINET6
# include <arpa/inet.h>
#endif /* NETINET || NETINET6 */

/* generic argument for functions in the command table */
struct arg_struct
{
    size_t      a_len;      /* length of buffer */
    char        *a_buf;     /* argument string */
    int     a_idx;      /* index for macro array */
    SMFICTX_PTR a_ctx;      /* context */
};

typedef struct arg_struct genarg;

/* structure for commands received from MTA */
struct cmdfct_t
{
    char    cm_cmd;             /* command */
    int cm_argt;            /* type of arguments expected */
    int cm_next;            /* next state */
    int cm_todo;            /* what to do next */
    int cm_macros;          /* index for macros */
    int (*cm_fct) __P((genarg *));  /* function to execute */
};

typedef struct cmdfct_t cmdfct;

/* possible values for cm_argt */
#define CM_ARG0 0   /* no args */
#define CM_ARG1 1   /* one arg (string) */
#define CM_ARG2 2   /* two args (strings) */
#define CM_ARGA 4   /* one string and _SOCK_ADDR */
#define CM_ARGO 5   /* two integers */
#define CM_ARGV 8   /* \0 separated list of args, NULL-terminated */
#define CM_ARGN 9   /* \0 separated list of args (strings) */

/* possible values for cm_todo */
#define CT_CONT     0x0000  /* continue reading commands */
#define CT_IGNO     0x0001  /* continue even when error  */

/* not needed right now, done via return code instead */
#define CT_KEEP     0x0004  /* keep buffer (contains symbols) */
#define CT_END      0x0008  /* last command of session, stop replying */

/* index in macro array: macros only for these commands */
#define CI_NONE     (-1)
#define CI_CONN     0
#define CI_HELO     1
#define CI_MAIL     2
#define CI_RCPT     3
#define CI_DATA     4
#define CI_EOM      5
#define CI_EOH      6
#define CI_LAST     CI_EOH
#if CI_LAST < CI_DATA
ERROR: do not compile with CI_LAST < CI_DATA
#endif
#if CI_LAST < CI_EOM
ERROR: do not compile with CI_LAST < CI_EOM
#endif
#if CI_LAST < CI_EOH
ERROR: do not compile with CI_LAST < CI_EOH
#endif
#if CI_LAST < CI_ENVRCPT
ERROR: do not compile with CI_LAST < CI_ENVRCPT
#endif
#if CI_LAST < CI_ENVFROM
ERROR: do not compile with CI_LAST < CI_ENVFROM
#endif
#if CI_LAST < CI_HELO
ERROR: do not compile with CI_LAST < CI_HELO
#endif
#if CI_LAST < CI_CONNECT
ERROR: do not compile with CI_LAST < CI_CONNECT
#endif
#if CI_LAST >= MAX_MACROS_ENTRIES
ERROR: do not compile with CI_LAST >= MAX_MACROS_ENTRIES
#endif

/* function prototypes */
static int  st_abortfct __P((genarg *));
static int  st_macros __P((genarg *));
static int  st_optionneg __P((genarg *));
static int  st_bodychunk __P((genarg *));
static int  st_connectinfo __P((genarg *));
static int  st_bodyend __P((genarg *));
static int  st_helo __P((genarg *));
static int  st_header __P((genarg *));
static int  st_sender __P((genarg *));
static int  st_rcpt __P((genarg *));
static int  st_unknown __P((genarg *));
static int  st_data __P((genarg *));
static int  st_eoh __P((genarg *));
static int  st_quit __P((genarg *));
static int  sendreply __P((sfsistat, socket_t, struct timeval *, SMFICTX_PTR));
static void fix_stm __P((SMFICTX_PTR));
static bool trans_ok __P((int, int));
static char **dec_argv __P((char *, size_t));
static int  dec_arg2 __P((char *, size_t, char **, char **));
static void mi_clr_symlist __P((SMFICTX_PTR));

#if _FFR_WORKERS_POOL
static bool     mi_rd_socket_ready __P((int));
#endif /* _FFR_WORKERS_POOL */

/* states */
#define ST_NONE (-1)
#define ST_INIT 0   /* initial state */
#define ST_OPTS 1   /* option negotiation */
#define ST_CONN 2   /* connection info */
#define ST_HELO 3   /* helo */
#define ST_MAIL 4   /* mail from */
#define ST_RCPT 5   /* rcpt to */
#define ST_DATA 6   /* data */
#define ST_HDRS 7   /* headers */
#define ST_EOHS 8   /* end of headers */
#define ST_BODY 9   /* body */
#define ST_ENDM 10  /* end of message */
#define ST_QUIT 11  /* quit */
#define ST_ABRT 12  /* abort */
#define ST_UNKN 13  /* unknown SMTP command */
#define ST_Q_NC 14  /* quit, new connection follows */
#define ST_LAST ST_Q_NC /* last valid state */
#define ST_SKIP 16  /* not a state but required for the state table */

/* in a mail transaction? must be before eom according to spec. */
#define ST_IN_MAIL(st)  ((st) >= ST_MAIL && (st) < ST_ENDM)

/*
**  set of next states
**  each state (ST_*) corresponds to bit in an int value (1 << state)
**  each state has a set of allowed transitions ('or' of bits of states)
**  so a state transition is valid if the mask of the next state
**  is set in the NX_* value
**  this function is coded in trans_ok(), see below.
*/

#define MI_MASK(x)  (0x0001 << (x)) /* generate a bit "mask" for a state */
#define NX_INIT (MI_MASK(ST_OPTS))
#define NX_OPTS (MI_MASK(ST_CONN) | MI_MASK(ST_UNKN))
#define NX_CONN (MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN))
#define NX_HELO (MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN))
#define NX_MAIL (MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | MI_MASK(ST_UNKN))
#define NX_RCPT (MI_MASK(ST_HDRS) | MI_MASK(ST_EOHS) | MI_MASK(ST_DATA) | \
         MI_MASK(ST_BODY) | MI_MASK(ST_ENDM) | \
         MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | MI_MASK(ST_UNKN))
#define NX_DATA (MI_MASK(ST_EOHS) | MI_MASK(ST_HDRS) | MI_MASK(ST_ABRT))
#define NX_HDRS (MI_MASK(ST_EOHS) | MI_MASK(ST_HDRS) | MI_MASK(ST_ABRT))
#define NX_EOHS (MI_MASK(ST_BODY) | MI_MASK(ST_ENDM) | MI_MASK(ST_ABRT))
#define NX_BODY (MI_MASK(ST_ENDM) | MI_MASK(ST_BODY) | MI_MASK(ST_ABRT))
#define NX_ENDM (MI_MASK(ST_QUIT) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN) | \
        MI_MASK(ST_Q_NC))
#define NX_QUIT 0
#define NX_ABRT 0
#define NX_UNKN (MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | \
         MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | \
         MI_MASK(ST_DATA) | \
         MI_MASK(ST_BODY) | MI_MASK(ST_UNKN) | \
         MI_MASK(ST_ABRT) | MI_MASK(ST_QUIT) | MI_MASK(ST_Q_NC))
#define NX_Q_NC (MI_MASK(ST_CONN) | MI_MASK(ST_UNKN))
#define NX_SKIP MI_MASK(ST_SKIP)

static int next_states[] =
{
      NX_INIT
    , NX_OPTS
    , NX_CONN
    , NX_HELO
    , NX_MAIL
    , NX_RCPT
    , NX_DATA
    , NX_HDRS
    , NX_EOHS
    , NX_BODY
    , NX_ENDM
    , NX_QUIT
    , NX_ABRT
    , NX_UNKN
    , NX_Q_NC
};

#define SIZE_NEXT_STATES    (sizeof(next_states) / sizeof(next_states[0]))

/* commands received by milter */
static cmdfct cmds[] =
{
  {SMFIC_ABORT, CM_ARG0, ST_ABRT,  CT_CONT, CI_NONE, st_abortfct    }
, {SMFIC_MACRO, CM_ARGV, ST_NONE,  CT_KEEP, CI_NONE, st_macros  }
, {SMFIC_BODY,  CM_ARG1, ST_BODY,  CT_CONT, CI_NONE, st_bodychunk   }
, {SMFIC_CONNECT, CM_ARG2, ST_CONN,  CT_CONT,   CI_CONN, st_connectinfo }
, {SMFIC_BODYEOB, CM_ARG1, ST_ENDM,  CT_CONT,   CI_EOM,  st_bodyend }
, {SMFIC_HELO,  CM_ARG1, ST_HELO,  CT_CONT, CI_HELO, st_helo    }
, {SMFIC_HEADER, CM_ARG2, ST_HDRS,  CT_CONT,    CI_NONE, st_header  }
, {SMFIC_MAIL,  CM_ARGV, ST_MAIL,  CT_CONT, CI_MAIL, st_sender  }
, {SMFIC_OPTNEG, CM_ARGO, ST_OPTS,  CT_CONT,    CI_NONE, st_optionneg   }
, {SMFIC_EOH,   CM_ARG0, ST_EOHS,  CT_CONT, CI_EOH,  st_eoh     }
, {SMFIC_QUIT,  CM_ARG0, ST_QUIT,  CT_END,  CI_NONE, st_quit    }
, {SMFIC_DATA,  CM_ARG0, ST_DATA,  CT_CONT, CI_DATA, st_data    }
, {SMFIC_RCPT,  CM_ARGV, ST_RCPT,  CT_IGNO, CI_RCPT, st_rcpt    }
, {SMFIC_UNKNOWN, CM_ARG1, ST_UNKN,  CT_IGNO,   CI_NONE, st_unknown }
, {SMFIC_QUIT_NC, CM_ARG0, ST_Q_NC,  CT_CONT,   CI_NONE, st_quit    }
};

/*
**  Additional (internal) reply codes;
**  must be coordinated wit libmilter/mfapi.h
*/

#define _SMFIS_KEEP 20
#define _SMFIS_ABORT    21
#define _SMFIS_OPTIONS  22
#define _SMFIS_NOREPLY  SMFIS_NOREPLY
#define _SMFIS_FAIL (-1)
#define _SMFIS_NONE (-2)

/*
**  MI_ENGINE -- receive commands and process them
**
**  Parameters:
**      ctx -- context structure
**
**  Returns:
**      MI_FAILURE/MI_SUCCESS
*/

int
mi_engine(ctx)
    SMFICTX_PTR ctx;
{
    size_t len;
    int i;
    socket_t sd;
    int ret = MI_SUCCESS;
    int ncmds = sizeof(cmds) / sizeof(cmdfct);
    int curstate = ST_INIT;
    int newstate;
    bool call_abort;
    sfsistat r;
    char cmd;
    char *buf = NULL;
    genarg arg;
    struct timeval timeout;
    int (*f) __P((genarg *));
    sfsistat (*fi_abort) __P((SMFICTX *));
    sfsistat (*fi_close) __P((SMFICTX *));

    arg.a_ctx = ctx;
    sd = ctx->ctx_sd;
    fi_abort = ctx->ctx_smfi->xxfi_abort;
#if _FFR_WORKERS_POOL
    curstate = ctx->ctx_state;
    if (curstate == ST_INIT)
    {
        mi_clr_macros(ctx, 0);
        fix_stm(ctx);
    }
#else   /* _FFR_WORKERS_POOL */
    mi_clr_macros(ctx, 0);
    fix_stm(ctx);
#endif  /* _FFR_WORKERS_POOL */
    r = _SMFIS_NONE;
    do
    {
        /* call abort only if in a mail transaction */
        call_abort = ST_IN_MAIL(curstate);
        timeout.tv_sec = ctx->ctx_timeout;
        timeout.tv_usec = 0;
        if (mi_stop() == MILTER_ABRT)
        {
            if (ctx->ctx_dbg > 3)
                sm_dprintf("[%ld] milter_abort\n",
                    (long) ctx->ctx_id);
            ret = MI_FAILURE;
            break;
        }

        /*
        **  Notice: buf is allocated by mi_rd_cmd() and it will
        **  usually be free()d after it has been used in f().
        **  However, if the function returns _SMFIS_KEEP then buf
        **  contains macros and will not be free()d.
        **  Hence r must be set to _SMFIS_NONE if a new buf is
        **  allocated to avoid problem with housekeeping, esp.
        **  if the code "break"s out of the loop.
        */

#if _FFR_WORKERS_POOL
        /* Is the socket ready to be read ??? */
        if (!mi_rd_socket_ready(sd))
        {
            ret = MI_CONTINUE;
            break;
        }
#endif  /* _FFR_WORKERS_POOL */

        r = _SMFIS_NONE;
        if ((buf = mi_rd_cmd(sd, &timeout, &cmd, &len,
                     ctx->ctx_smfi->xxfi_name)) == NULL &&
            cmd < SMFIC_VALIDCMD)
        {
            if (ctx->ctx_dbg > 5)
                sm_dprintf("[%ld] mi_engine: mi_rd_cmd error (%x)\n",
                    (long) ctx->ctx_id, (int) cmd);

            /*
            **  eof is currently treated as failure ->
            **  abort() instead of close(), otherwise use:
            **  if (cmd != SMFIC_EOF)
            */

            ret = MI_FAILURE;
            break;
        }
        if (ctx->ctx_dbg > 4)
            sm_dprintf("[%ld] got cmd '%c' len %d\n",
                (long) ctx->ctx_id, cmd, (int) len);
        for (i = 0; i < ncmds; i++)
        {
            if (cmd == cmds[i].cm_cmd)
                break;
        }
        if (i >= ncmds)
        {
            /* unknown command */
            if (ctx->ctx_dbg > 1)
                sm_dprintf("[%ld] cmd '%c' unknown\n",
                    (long) ctx->ctx_id, cmd);
            ret = MI_FAILURE;
            break;
        }
        if ((f = cmds[i].cm_fct) == NULL)
        {
            /* stop for now */
            if (ctx->ctx_dbg > 1)
                sm_dprintf("[%ld] cmd '%c' not impl\n",
                    (long) ctx->ctx_id, cmd);
            ret = MI_FAILURE;
            break;
        }

        /* is new state ok? */
        newstate = cmds[i].cm_next;
        if (ctx->ctx_dbg > 5)
            sm_dprintf("[%ld] cur %x new %x nextmask %x\n",
                (long) ctx->ctx_id,
                curstate, newstate, next_states[curstate]);

        if (newstate != ST_NONE && !trans_ok(curstate, newstate))
        {
            if (ctx->ctx_dbg > 1)
                sm_dprintf("[%ld] abort: cur %d (%x) new %d (%x) next %x\n",
                    (long) ctx->ctx_id,
                    curstate, MI_MASK(curstate),
                    newstate, MI_MASK(newstate),
                    next_states[curstate]);

            /* call abort only if in a mail transaction */
            if (fi_abort != NULL && call_abort)
                (void) (*fi_abort)(ctx);

            /*
            **  try to reach the new state from HELO
            **  if it can't be reached, ignore the command.
            */

            curstate = ST_HELO;
            if (!trans_ok(curstate, newstate))
            {
                if (buf != NULL)
                {
                    free(buf);
                    buf = NULL;
                }
                continue;
            }
        }
        arg.a_len = len;
        arg.a_buf = buf;
        if (newstate != ST_NONE)
        {
            curstate = newstate;
            ctx->ctx_state = curstate;
        }
        arg.a_idx = cmds[i].cm_macros;
        call_abort = ST_IN_MAIL(curstate);

        /* call function to deal with command */
        MI_MONITOR_BEGIN(ctx, cmd);
        r = (*f)(&arg);
        MI_MONITOR_END(ctx, cmd);
        if (r != _SMFIS_KEEP && buf != NULL)
        {
            free(buf);
            buf = NULL;
        }
        if (sendreply(r, sd, &timeout, ctx) != MI_SUCCESS)
        {
            ret = MI_FAILURE;
            break;
        }

        if (r == SMFIS_ACCEPT)
        {
            /* accept mail, no further actions taken */
            curstate = ST_HELO;
        }
        else if (r == SMFIS_REJECT || r == SMFIS_DISCARD ||
             r ==  SMFIS_TEMPFAIL)
        {
            /*
            **  further actions depend on current state
            **  if the IGNO bit is set: "ignore" the error,
            **  i.e., stay in the current state
            */
            if (!bitset(CT_IGNO, cmds[i].cm_todo))
                curstate = ST_HELO;
        }
        else if (r == _SMFIS_ABORT)
        {
            if (ctx->ctx_dbg > 5)
                sm_dprintf("[%ld] function returned abort\n",
                    (long) ctx->ctx_id);
            ret = MI_FAILURE;
            break;
        }
    } while (!bitset(CT_END, cmds[i].cm_todo));

    ctx->ctx_state = curstate;

    if (ret == MI_FAILURE)
    {
        /* call abort only if in a mail transaction */
        if (fi_abort != NULL && call_abort)
            (void) (*fi_abort)(ctx);
    }

    /* has close been called? */
    if (ctx->ctx_state != ST_QUIT
#if _FFR_WORKERS_POOL
       && ret != MI_CONTINUE
#endif /* _FFR_WORKERS_POOL */
       )
    {
        if ((fi_close = ctx->ctx_smfi->xxfi_close) != NULL)
            (void) (*fi_close)(ctx);
    }
    if (r != _SMFIS_KEEP && buf != NULL)
        free(buf);
#if !_FFR_WORKERS_POOL
    mi_clr_macros(ctx, 0);
#endif /* _FFR_WORKERS_POOL */
    return ret;
}

static size_t milter_addsymlist __P((SMFICTX_PTR, char *, char **));

static size_t
milter_addsymlist(ctx, buf, newbuf)
    SMFICTX_PTR ctx;
    char *buf;
    char **newbuf;
{
    size_t len;
    int i;
    mi_int32 v;
    char *buffer;

    SM_ASSERT(ctx != NULL);
    SM_ASSERT(buf != NULL);
    SM_ASSERT(newbuf != NULL);
    len = 0;
    for (i = 0; i < MAX_MACROS_ENTRIES; i++)
    {
        if (ctx->ctx_mac_list[i] != NULL)
        {
            len += strlen(ctx->ctx_mac_list[i]) + 1 +
                MILTER_LEN_BYTES;
        }
    }
    if (len > 0)
    {
        size_t offset;

        SM_ASSERT(len + MILTER_OPTLEN > len);
        len += MILTER_OPTLEN;
        buffer = malloc(len);
        if (buffer != NULL)
        {
            (void) memcpy(buffer, buf, MILTER_OPTLEN);
            offset = MILTER_OPTLEN;
            for (i = 0; i < MAX_MACROS_ENTRIES; i++)
            {
                size_t l;

                if (ctx->ctx_mac_list[i] == NULL)
                    continue;

                SM_ASSERT(offset + MILTER_LEN_BYTES < len);
                v = htonl(i);
                (void) memcpy(buffer + offset, (void *) &v,
                        MILTER_LEN_BYTES);
                offset += MILTER_LEN_BYTES;
                l = strlen(ctx->ctx_mac_list[i]) + 1;
                SM_ASSERT(offset + l <= len);
                (void) memcpy(buffer + offset,
                        ctx->ctx_mac_list[i], l);
                offset += l;
            }
        }
        else
        {
            /* oops ... */
        }
    }
    else
    {
        len = MILTER_OPTLEN;
        buffer = buf;
    }
    *newbuf = buffer;
    return len;
}

/*
**  GET_NR_BIT -- get "no reply" bit matching state
**
**  Parameters:
**      state -- current protocol stage
**
**  Returns:
**      0: no matching bit
**      >0: the matching "no reply" bit
*/

static unsigned long get_nr_bit __P((int));

static unsigned long
get_nr_bit(state)
    int state;
{
    unsigned long bit;

    switch (state)
    {
      case ST_CONN:
        bit = SMFIP_NR_CONN;
        break;
      case ST_HELO:
        bit = SMFIP_NR_HELO;
        break;
      case ST_MAIL:
        bit = SMFIP_NR_MAIL;
        break;
      case ST_RCPT:
        bit = SMFIP_NR_RCPT;
        break;
      case ST_DATA:
        bit = SMFIP_NR_DATA;
        break;
      case ST_UNKN:
        bit = SMFIP_NR_UNKN;
        break;
      case ST_HDRS:
        bit = SMFIP_NR_HDR;
        break;
      case ST_EOHS:
        bit = SMFIP_NR_EOH;
        break;
      case ST_BODY:
        bit = SMFIP_NR_BODY;
        break;
      default:
        bit = 0;
        break;
    }
    return bit;
}

/*
**  SENDREPLY -- send a reply to the MTA
**
**  Parameters:
**      r -- reply code
**      sd -- socket descriptor
**      timeout_ptr -- (ptr to) timeout to use for sending
**      ctx -- context structure
**
**  Returns:
**      MI_SUCCESS/MI_FAILURE
*/

static int
sendreply(r, sd, timeout_ptr, ctx)
    sfsistat r;
    socket_t sd;
    struct timeval *timeout_ptr;
    SMFICTX_PTR ctx;
{
    int ret;
    unsigned long bit;

    ret = MI_SUCCESS;

    bit = get_nr_bit(ctx->ctx_state);
    if (bit != 0 && (ctx->ctx_pflags & bit) != 0 && r != SMFIS_NOREPLY)
    {
        if (r >= SMFIS_CONTINUE && r < _SMFIS_KEEP)
        {
            /* milter said it wouldn't reply, but it lied... */
            smi_log(SMI_LOG_ERR,
                "%s: milter claimed not to reply in state %d but did anyway %d\n",
                ctx->ctx_smfi->xxfi_name,
                ctx->ctx_state, r);

        }

        /*
        **  Force specified behavior, otherwise libmilter
        **  and MTA will fail to communicate properly.
        */

        switch (r)
        {
          case SMFIS_CONTINUE:
          case SMFIS_TEMPFAIL:
          case SMFIS_REJECT:
          case SMFIS_DISCARD:
          case SMFIS_ACCEPT:
          case SMFIS_SKIP:
          case _SMFIS_OPTIONS:
            r = SMFIS_NOREPLY;
            break;
        }
    }

    switch (r)
    {
      case SMFIS_CONTINUE:
        ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_CONTINUE, NULL, 0);
        break;
      case SMFIS_TEMPFAIL:
      case SMFIS_REJECT:
        if (ctx->ctx_reply != NULL &&
            ((r == SMFIS_TEMPFAIL && *ctx->ctx_reply == '4') ||
             (r == SMFIS_REJECT && *ctx->ctx_reply == '5')))
        {
            ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_REPLYCODE,
                    ctx->ctx_reply,
                    strlen(ctx->ctx_reply) + 1);
            free(ctx->ctx_reply);
            ctx->ctx_reply = NULL;
        }
        else
        {
            ret = mi_wr_cmd(sd, timeout_ptr, r == SMFIS_REJECT ?
                    SMFIR_REJECT : SMFIR_TEMPFAIL, NULL, 0);
        }
        break;
      case SMFIS_DISCARD:
        ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_DISCARD, NULL, 0);
        break;
      case SMFIS_ACCEPT:
        ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_ACCEPT, NULL, 0);
        break;
      case SMFIS_SKIP:
        ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_SKIP, NULL, 0);
        break;
      case _SMFIS_OPTIONS:
        {
            mi_int32 v;
            size_t len;
            char *buffer;
            char buf[MILTER_OPTLEN];

            v = htonl(ctx->ctx_prot_vers2mta);
            (void) memcpy(&(buf[0]), (void *) &v,
                      MILTER_LEN_BYTES);
            v = htonl(ctx->ctx_aflags);
            (void) memcpy(&(buf[MILTER_LEN_BYTES]), (void *) &v,
                      MILTER_LEN_BYTES);
            v = htonl(ctx->ctx_pflags2mta);
            (void) memcpy(&(buf[MILTER_LEN_BYTES * 2]),
                      (void *) &v, MILTER_LEN_BYTES);
            len = milter_addsymlist(ctx, buf, &buffer);
            if (buffer != NULL)
                ret = mi_wr_cmd(sd, timeout_ptr, SMFIC_OPTNEG,
                        buffer, len);
            else
                ret = MI_FAILURE;
        }
        break;
      case SMFIS_NOREPLY:
        if (bit != 0 &&
            (ctx->ctx_pflags & bit) != 0 &&
            (ctx->ctx_mta_pflags & bit) == 0)
        {
            /*
            **  milter doesn't want to send a reply,
            **  but the MTA doesn't have that feature: fake it.
            */

            ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_CONTINUE, NULL,
                    0);
        }
        break;
      default:  /* don't send a reply */
        break;
    }
    return ret;
}

/*
**  CLR_MACROS -- clear set of macros starting from a given index
**
**  Parameters:
**      ctx -- context structure
**      m -- index from which to clear all macros
**
**  Returns:
**      None.
*/

void
mi_clr_macros(ctx, m)
    SMFICTX_PTR ctx;
    int m;
{
    int i;

    for (i = m; i < MAX_MACROS_ENTRIES; i++)
    {
        if (ctx->ctx_mac_ptr[i] != NULL)
        {
            free(ctx->ctx_mac_ptr[i]);
            ctx->ctx_mac_ptr[i] = NULL;
        }
        if (ctx->ctx_mac_buf[i] != NULL)
        {
            free(ctx->ctx_mac_buf[i]);
            ctx->ctx_mac_buf[i] = NULL;
        }
    }
}

/*
**  MI_CLR_SYMLIST -- clear list of macros
**
**  Parameters:
**      ctx -- context structure
**
**  Returns:
**      None.
*/

static void
mi_clr_symlist(ctx)
    SMFICTX *ctx;
{
    int i;

    SM_ASSERT(ctx != NULL);
    for (i = SMFIM_FIRST; i <= SMFIM_LAST; i++)
    {
        if (ctx->ctx_mac_list[i] != NULL)
        {
            free(ctx->ctx_mac_list[i]);
            ctx->ctx_mac_list[i] = NULL;
        }
    }
}

/*
**  MI_CLR_CTX -- clear context
**
**  Parameters:
**      ctx -- context structure
**
**  Returns:
**      None.
*/

void
mi_clr_ctx(ctx)
    SMFICTX *ctx;
{
    SM_ASSERT(ctx != NULL);
    if (ValidSocket(ctx->ctx_sd))
    {
        (void) closesocket(ctx->ctx_sd);
        ctx->ctx_sd = INVALID_SOCKET;
    }
    if (ctx->ctx_reply != NULL)
    {
        free(ctx->ctx_reply);
        ctx->ctx_reply = NULL;
    }
    if (ctx->ctx_privdata != NULL)
    {
        smi_log(SMI_LOG_WARN,
            "%s: private data not NULL",
            ctx->ctx_smfi->xxfi_name);
    }
    mi_clr_macros(ctx, 0);
    mi_clr_symlist(ctx);
    free(ctx);
}

/*
**  ST_OPTIONNEG -- negotiate options
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      abort/send options/continue
*/

static int
st_optionneg(g)
    genarg *g;
{
    mi_int32 i, v, fake_pflags, internal_pflags;
    SMFICTX_PTR ctx;
#if _FFR_MILTER_CHECK
    bool testmode = false;
#endif /* _FFR_MILTER_CHECK */
    int (*fi_negotiate) __P((SMFICTX *,
                    unsigned long, unsigned long,
                    unsigned long, unsigned long,
                    unsigned long *, unsigned long *,
                    unsigned long *, unsigned long *));

    if (g == NULL || g->a_ctx->ctx_smfi == NULL)
        return SMFIS_CONTINUE;
    ctx = g->a_ctx;
    mi_clr_macros(ctx, g->a_idx + 1);
    ctx->ctx_prot_vers = SMFI_PROT_VERSION;

    /* check for minimum length */
    if (g->a_len < MILTER_OPTLEN)
    {
        smi_log(SMI_LOG_ERR,
            "%s: st_optionneg[%ld]: len too short %d < %d",
            ctx->ctx_smfi->xxfi_name,
            (long) ctx->ctx_id, (int) g->a_len,
            MILTER_OPTLEN);
        return _SMFIS_ABORT;
    }

    /* protocol version */
    (void) memcpy((void *) &i, (void *) &(g->a_buf[0]), MILTER_LEN_BYTES);
    v = ntohl(i);

#define SMFI_PROT_VERSION_MIN   2

    /* check for minimum version */
    if (v < SMFI_PROT_VERSION_MIN)
    {
        smi_log(SMI_LOG_ERR,
            "%s: st_optionneg[%ld]: protocol version too old %d < %d",
            ctx->ctx_smfi->xxfi_name,
            (long) ctx->ctx_id, v, SMFI_PROT_VERSION_MIN);
        return _SMFIS_ABORT;
    }
    ctx->ctx_mta_prot_vers = v;
    if (ctx->ctx_prot_vers < ctx->ctx_mta_prot_vers)
        ctx->ctx_prot_vers2mta = ctx->ctx_prot_vers;
    else
        ctx->ctx_prot_vers2mta = ctx->ctx_mta_prot_vers;

    (void) memcpy((void *) &i, (void *) &(g->a_buf[MILTER_LEN_BYTES]),
              MILTER_LEN_BYTES);
    v = ntohl(i);

    /* no flags? set to default value for V1 actions */
    if (v == 0)
        v = SMFI_V1_ACTS;
    ctx->ctx_mta_aflags = v;    /* MTA action flags */

    internal_pflags = 0;
    (void) memcpy((void *) &i, (void *) &(g->a_buf[MILTER_LEN_BYTES * 2]),
              MILTER_LEN_BYTES);
    v = ntohl(i);

    /* no flags? set to default value for V1 protocol */
    if (v == 0)
        v = SMFI_V1_PROT;
#if _FFR_MDS_NEGOTIATE
    else if (ctx->ctx_smfi->xxfi_version >= SMFI_VERSION_MDS)
    {
        /*
        **  Allow changing the size only if milter is compiled
        **  against a version that supports this.
        **  If a milter is dynamically linked against a newer
        **  libmilter version, we don't want to "surprise"
        **  it with a larger buffer as it may rely on it
        **  even though it is not documented as a limit.
        */

        if (bitset(SMFIP_MDS_1M, v))
        {
            internal_pflags |= SMFIP_MDS_1M;
            (void) smfi_setmaxdatasize(MILTER_MDS_1M);
        }
        else if (bitset(SMFIP_MDS_256K, v))
        {
            internal_pflags |= SMFIP_MDS_256K;
            (void) smfi_setmaxdatasize(MILTER_MDS_256K);
        }
    }
# if 0
    /* don't log this for now... */
    else if (ctx->ctx_smfi->xxfi_version < SMFI_VERSION_MDS &&
         bitset(SMFIP_MDS_1M|SMFIP_MDS_256K, v))
    {
        smi_log(SMI_LOG_WARN,
            "%s: st_optionneg[%ld]: milter version=%X, trying flags=%X",
            ctx->ctx_smfi->xxfi_name,
            (long) ctx->ctx_id, ctx->ctx_smfi->xxfi_version, v);
    }
# endif /* 0 */
#endif /* _FFR_MDS_NEGOTIATE */

    /*
    **  MTA protocol flags.
    **  We pass the internal flags to the milter as "read only",
    **  i.e., a milter can read them so it knows which size
    **  will be used, but any changes by a milter will be ignored
    **  (see below, search for SMFI_INTERNAL).
    */

    ctx->ctx_mta_pflags = (v & ~SMFI_INTERNAL) | internal_pflags;

    /*
    **  Copy flags from milter struct into libmilter context;
    **  this variable will be used later on to check whether
    **  the MTA "actions" can fulfill the milter requirements,
    **  but it may be overwritten by the negotiate callback.
    */

    ctx->ctx_aflags = ctx->ctx_smfi->xxfi_flags;
    fake_pflags = SMFIP_NR_CONN
            |SMFIP_NR_HELO
            |SMFIP_NR_MAIL
            |SMFIP_NR_RCPT
            |SMFIP_NR_DATA
            |SMFIP_NR_UNKN
            |SMFIP_NR_HDR
            |SMFIP_NR_EOH
            |SMFIP_NR_BODY
            ;

    if (g->a_ctx->ctx_smfi != NULL &&
        g->a_ctx->ctx_smfi->xxfi_version > 4 &&
        (fi_negotiate = g->a_ctx->ctx_smfi->xxfi_negotiate) != NULL)
    {
        int r;
        unsigned long m_aflags, m_pflags, m_f2, m_f3;

        /*
        **  let milter decide whether the features offered by the
        **  MTA are "good enough".
        **  Notes:
        **  - libmilter can "fake" some features (e.g., SMFIP_NR_HDR)
        **  - m_f2, m_f3 are for future extensions
        */

        m_f2 = m_f3 = 0;
        m_aflags = ctx->ctx_mta_aflags;
        m_pflags = ctx->ctx_pflags;
        if ((SMFIP_SKIP & ctx->ctx_mta_pflags) != 0)
            m_pflags |= SMFIP_SKIP;
        r = fi_negotiate(g->a_ctx,
                ctx->ctx_mta_aflags,
                ctx->ctx_mta_pflags|fake_pflags,
                0, 0,
                &m_aflags, &m_pflags, &m_f2, &m_f3);

#if _FFR_MILTER_CHECK
        testmode = bitset(SMFIP_TEST, m_pflags);
        if (testmode)
            m_pflags &= ~SMFIP_TEST;
#endif /* _FFR_MILTER_CHECK */

        /*
        **  Types of protocol flags (pflags):
        **  1. do NOT send protocol step X
        **  2. MTA can do/understand something extra (SKIP,
        **  send unknown RCPTs)
        **  3. MTA can deal with "no reply" for various protocol steps
        **  Note: this mean that it isn't possible to simply set all
        **  flags to get "everything":
        **  setting a flag of type 1 turns off a step
        **      (it should be the other way around:
        **      a flag means a protocol step can be sent)
        **  setting a flag of type 3 requires that milter
        **  never sends a reply for the corresponding step.
        **  Summary: the "negation" of protocol flags is causing
        **  problems, but at least for type 3 there is no simple
        **  solution.
        **
        **  What should "all options" mean?
        **  send all protocol steps _except_ those for which there is
        **  no callback (currently registered in ctx_pflags)
        **  expect SKIP as return code?     Yes
        **  send unknown RCPTs?         No,
        **              must be explicitly requested?
        **  "no reply" for some protocol steps? No,
        **              must be explicitly requested.
        */

        if (SMFIS_ALL_OPTS == r)
        {
            ctx->ctx_aflags = ctx->ctx_mta_aflags;
            ctx->ctx_pflags2mta = ctx->ctx_pflags;
            if ((SMFIP_SKIP & ctx->ctx_mta_pflags) != 0)
                ctx->ctx_pflags2mta |= SMFIP_SKIP;
        }
        else if (r != SMFIS_CONTINUE)
        {
            smi_log(SMI_LOG_ERR,
                "%s: st_optionneg[%ld]: xxfi_negotiate returned %d (protocol options=0x%lx, actions=0x%lx)",
                ctx->ctx_smfi->xxfi_name,
                (long) ctx->ctx_id, r, ctx->ctx_mta_pflags,
                ctx->ctx_mta_aflags);
            return _SMFIS_ABORT;
        }
        else
        {
            ctx->ctx_aflags = m_aflags;
            ctx->ctx_pflags = m_pflags;
            ctx->ctx_pflags2mta = m_pflags;
        }

        /* check whether some flags need to be "faked" */
        i = ctx->ctx_pflags2mta;
        if ((ctx->ctx_mta_pflags & i) != i)
        {
            unsigned int idx;
            unsigned long b;

            /*
            **  If some behavior can be faked (set in fake_pflags),
            **  but the MTA doesn't support it, then unset
            **  that flag in the value that is sent to the MTA.
            */

            for (idx = 0; idx < 32; idx++)
            {
                b = 1 << idx;
                if ((ctx->ctx_mta_pflags & b) != b &&
                    (fake_pflags & b) == b)
                    ctx->ctx_pflags2mta &= ~b;
            }
        }
    }
    else
    {
        /*
        **  Set the protocol flags based on the values determined
        **  in mi_listener() which checked the defined callbacks.
        */

        ctx->ctx_pflags2mta = ctx->ctx_pflags;
    }

    /* check whether actions and protocol requirements can be satisfied */
    i = ctx->ctx_aflags;
    if ((i & ctx->ctx_mta_aflags) != i)
    {
        smi_log(SMI_LOG_ERR,
            "%s: st_optionneg[%ld]: 0x%lx does not fulfill action requirements 0x%x",
            ctx->ctx_smfi->xxfi_name,
            (long) ctx->ctx_id, ctx->ctx_mta_aflags, i);
        return _SMFIS_ABORT;
    }

    i = ctx->ctx_pflags2mta;
    if ((ctx->ctx_mta_pflags & i) != i)
    {
        /*
        **  Older MTAs do not support some protocol steps.
        **  As this protocol is a bit "wierd" (it asks for steps
        **  NOT to be taken/sent) we have to check whether we
        **  should turn off those "negative" requests.
        **  Currently these are only SMFIP_NODATA and SMFIP_NOUNKNOWN.
        */

        if (bitset(SMFIP_NODATA, ctx->ctx_pflags2mta) &&
            !bitset(SMFIP_NODATA, ctx->ctx_mta_pflags))
            ctx->ctx_pflags2mta &= ~SMFIP_NODATA;
        if (bitset(SMFIP_NOUNKNOWN, ctx->ctx_pflags2mta) &&
            !bitset(SMFIP_NOUNKNOWN, ctx->ctx_mta_pflags))
            ctx->ctx_pflags2mta &= ~SMFIP_NOUNKNOWN;
        i = ctx->ctx_pflags2mta;
    }

    if ((ctx->ctx_mta_pflags & i) != i)
    {
        smi_log(SMI_LOG_ERR,
            "%s: st_optionneg[%ld]: 0x%lx does not fulfill protocol requirements 0x%x",
            ctx->ctx_smfi->xxfi_name,
            (long) ctx->ctx_id, ctx->ctx_mta_pflags, i);
        return _SMFIS_ABORT;
    }
    fix_stm(ctx);

    if (ctx->ctx_dbg > 3)
        sm_dprintf("[%ld] milter_negotiate:"
            " mta_actions=0x%lx, mta_flags=0x%lx"
            " actions=0x%lx, flags=0x%lx\n"
            , (long) ctx->ctx_id
            , ctx->ctx_mta_aflags, ctx->ctx_mta_pflags
            , ctx->ctx_aflags, ctx->ctx_pflags);

#if _FFR_MILTER_CHECK
    if (ctx->ctx_dbg > 3)
        sm_dprintf("[%ld] milter_negotiate:"
            " testmode=%d, pflags2mta=%X, internal_pflags=%X\n"
            , (long) ctx->ctx_id, testmode
            , ctx->ctx_pflags2mta, internal_pflags);

    /* in test mode: take flags without further modifications */
    if (!testmode)
        /* Warning: check statement below! */
#endif /* _FFR_MILTER_CHECK */

    /*
    **  Remove the internal flags that might have been set by a milter
    **  and set only those determined above.
    */

    ctx->ctx_pflags2mta = (ctx->ctx_pflags2mta & ~SMFI_INTERNAL)
                  | internal_pflags;
    return _SMFIS_OPTIONS;
}

/*
**  ST_CONNECTINFO -- receive connection information
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_connectinfo(g)
    genarg *g;
{
    size_t l;
    size_t i;
    char *s, family;
    unsigned short port = 0;
    _SOCK_ADDR sockaddr;
    sfsistat (*fi_connect) __P((SMFICTX *, char *, _SOCK_ADDR *));

    if (g == NULL)
        return _SMFIS_ABORT;
    mi_clr_macros(g->a_ctx, g->a_idx + 1);
    if (g->a_ctx->ctx_smfi == NULL ||
        (fi_connect = g->a_ctx->ctx_smfi->xxfi_connect) == NULL)
        return SMFIS_CONTINUE;

    s = g->a_buf;
    i = 0;
    l = g->a_len;
    while (s[i] != '\0' && i <= l)
        ++i;
    if (i + 1 >= l)
        return _SMFIS_ABORT;

    /* Move past trailing \0 in host string */
    i++;
    family = s[i++];
    (void) memset(&sockaddr, '\0', sizeof sockaddr);
    if (family != SMFIA_UNKNOWN)
    {
        if (i + sizeof port >= l)
        {
            smi_log(SMI_LOG_ERR,
                "%s: connect[%ld]: wrong len %d >= %d",
                g->a_ctx->ctx_smfi->xxfi_name,
                (long) g->a_ctx->ctx_id, (int) i, (int) l);
            return _SMFIS_ABORT;
        }
        (void) memcpy((void *) &port, (void *) (s + i),
                  sizeof port);
        i += sizeof port;

        /* make sure string is terminated */
        if (s[l - 1] != '\0')
            return _SMFIS_ABORT;
# if NETINET
        if (family == SMFIA_INET)
        {
            if (inet_aton(s + i, (struct in_addr *) &sockaddr.sin.sin_addr)
                != 1)
            {
                smi_log(SMI_LOG_ERR,
                    "%s: connect[%ld]: inet_aton failed",
                    g->a_ctx->ctx_smfi->xxfi_name,
                    (long) g->a_ctx->ctx_id);
                return _SMFIS_ABORT;
            }
            sockaddr.sa.sa_family = AF_INET;
            if (port > 0)
                sockaddr.sin.sin_port = port;
        }
        else
# endif /* NETINET */
# if NETINET6
        if (family == SMFIA_INET6)
        {
            if (mi_inet_pton(AF_INET6, s + i,
                     &sockaddr.sin6.sin6_addr) != 1)
            {
                smi_log(SMI_LOG_ERR,
                    "%s: connect[%ld]: mi_inet_pton failed",
                    g->a_ctx->ctx_smfi->xxfi_name,
                    (long) g->a_ctx->ctx_id);
                return _SMFIS_ABORT;
            }
            sockaddr.sa.sa_family = AF_INET6;
            if (port > 0)
                sockaddr.sin6.sin6_port = port;
        }
        else
# endif /* NETINET6 */
# if NETUNIX
        if (family == SMFIA_UNIX)
        {
            if (sm_strlcpy(sockaddr.sunix.sun_path, s + i,
                sizeof sockaddr.sunix.sun_path) >=
                sizeof sockaddr.sunix.sun_path)
            {
                smi_log(SMI_LOG_ERR,
                    "%s: connect[%ld]: path too long",
                    g->a_ctx->ctx_smfi->xxfi_name,
                    (long) g->a_ctx->ctx_id);
                return _SMFIS_ABORT;
            }
            sockaddr.sunix.sun_family = AF_UNIX;
        }
        else
# endif /* NETUNIX */
        {
            smi_log(SMI_LOG_ERR,
                "%s: connect[%ld]: unknown family %d",
                g->a_ctx->ctx_smfi->xxfi_name,
                (long) g->a_ctx->ctx_id, family);
            return _SMFIS_ABORT;
        }
    }
    return (*fi_connect)(g->a_ctx, g->a_buf,
                 family != SMFIA_UNKNOWN ? &sockaddr : NULL);
}

/*
**  ST_EOH -- end of headers
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_eoh(g)
    genarg *g;
{
    sfsistat (*fi_eoh) __P((SMFICTX *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi != NULL &&
        (fi_eoh = g->a_ctx->ctx_smfi->xxfi_eoh) != NULL)
        return (*fi_eoh)(g->a_ctx);
    return SMFIS_CONTINUE;
}

/*
**  ST_DATA -- DATA command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_data(g)
    genarg *g;
{
    sfsistat (*fi_data) __P((SMFICTX *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi != NULL &&
        g->a_ctx->ctx_smfi->xxfi_version > 3 &&
        (fi_data = g->a_ctx->ctx_smfi->xxfi_data) != NULL)
        return (*fi_data)(g->a_ctx);
    return SMFIS_CONTINUE;
}

/*
**  ST_HELO -- helo/ehlo command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_helo(g)
    genarg *g;
{
    sfsistat (*fi_helo) __P((SMFICTX *, char *));

    if (g == NULL)
        return _SMFIS_ABORT;
    mi_clr_macros(g->a_ctx, g->a_idx + 1);
    if (g->a_ctx->ctx_smfi != NULL &&
        (fi_helo = g->a_ctx->ctx_smfi->xxfi_helo) != NULL)
    {
        /* paranoia: check for terminating '\0' */
        if (g->a_len == 0 || g->a_buf[g->a_len - 1] != '\0')
            return MI_FAILURE;
        return (*fi_helo)(g->a_ctx, g->a_buf);
    }
    return SMFIS_CONTINUE;
}

/*
**  ST_HEADER -- header line
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_header(g)
    genarg *g;
{
    char *hf, *hv;
    sfsistat (*fi_header) __P((SMFICTX *, char *, char *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi == NULL ||
        (fi_header = g->a_ctx->ctx_smfi->xxfi_header) == NULL)
        return SMFIS_CONTINUE;
    if (dec_arg2(g->a_buf, g->a_len, &hf, &hv) == MI_SUCCESS)
        return (*fi_header)(g->a_ctx, hf, hv);
    else
        return _SMFIS_ABORT;
}

#define ARGV_FCT(lf, rf, idx)                   \
    char **argv;                        \
    sfsistat (*lf) __P((SMFICTX *, char **));       \
    int r;                          \
                                \
    if (g == NULL)                      \
        return _SMFIS_ABORT;                \
    mi_clr_macros(g->a_ctx, g->a_idx + 1);          \
    if (g->a_ctx->ctx_smfi == NULL ||           \
        (lf = g->a_ctx->ctx_smfi->rf) == NULL)      \
        return SMFIS_CONTINUE;              \
    if ((argv = dec_argv(g->a_buf, g->a_len)) == NULL)  \
        return _SMFIS_ABORT;                \
    r = (*lf)(g->a_ctx, argv);              \
    free(argv);                     \
    return r;

/*
**  ST_SENDER -- MAIL FROM command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_sender(g)
    genarg *g;
{
    ARGV_FCT(fi_envfrom, xxfi_envfrom, CI_MAIL)
}

/*
**  ST_RCPT -- RCPT TO command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_rcpt(g)
    genarg *g;
{
    ARGV_FCT(fi_envrcpt, xxfi_envrcpt, CI_RCPT)
}

/*
**  ST_UNKNOWN -- unrecognized or unimplemented command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_unknown(g)
    genarg *g;
{
    sfsistat (*fi_unknown) __P((SMFICTX *, const char *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi != NULL &&
        g->a_ctx->ctx_smfi->xxfi_version > 2 &&
        (fi_unknown = g->a_ctx->ctx_smfi->xxfi_unknown) != NULL)
        return (*fi_unknown)(g->a_ctx, (const char *) g->a_buf);
    return SMFIS_CONTINUE;
}

/*
**  ST_MACROS -- deal with macros received from the MTA
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue/keep
**
**  Side effects:
**      set pointer in macro array to current values.
*/

static int
st_macros(g)
    genarg *g;
{
    int i;
    char **argv;

    if (g == NULL || g->a_len < 1)
        return _SMFIS_FAIL;
    if ((argv = dec_argv(g->a_buf + 1, g->a_len - 1)) == NULL)
        return _SMFIS_FAIL;
    switch (g->a_buf[0])
    {
      case SMFIC_CONNECT:
        i = CI_CONN;
        break;
      case SMFIC_HELO:
        i = CI_HELO;
        break;
      case SMFIC_MAIL:
        i = CI_MAIL;
        break;
      case SMFIC_RCPT:
        i = CI_RCPT;
        break;
      case SMFIC_DATA:
        i = CI_DATA;
        break;
      case SMFIC_BODYEOB:
        i = CI_EOM;
        break;
      case SMFIC_EOH:
        i = CI_EOH;
        break;
      default:
        free(argv);
        return _SMFIS_FAIL;
    }
    if (g->a_ctx->ctx_mac_ptr[i] != NULL)
        free(g->a_ctx->ctx_mac_ptr[i]);
    if (g->a_ctx->ctx_mac_buf[i] != NULL)
        free(g->a_ctx->ctx_mac_buf[i]);
    g->a_ctx->ctx_mac_ptr[i] = argv;
    g->a_ctx->ctx_mac_buf[i] = g->a_buf;
    return _SMFIS_KEEP;
}

/*
**  ST_QUIT -- quit command
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      noreply
*/

/* ARGSUSED */
static int
st_quit(g)
    genarg *g;
{
    sfsistat (*fi_close) __P((SMFICTX *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi != NULL &&
        (fi_close = g->a_ctx->ctx_smfi->xxfi_close) != NULL)
        (void) (*fi_close)(g->a_ctx);
    mi_clr_macros(g->a_ctx, 0);
    return _SMFIS_NOREPLY;
}

/*
**  ST_BODYCHUNK -- deal with a piece of the mail body
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
*/

static int
st_bodychunk(g)
    genarg *g;
{
    sfsistat (*fi_body) __P((SMFICTX *, unsigned char *, size_t));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g->a_ctx->ctx_smfi != NULL &&
        (fi_body = g->a_ctx->ctx_smfi->xxfi_body) != NULL)
        return (*fi_body)(g->a_ctx, (unsigned char *)g->a_buf,
                  g->a_len);
    return SMFIS_CONTINUE;
}

/*
**  ST_BODYEND -- deal with the last piece of the mail body
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      continue or filter-specified value
**
**  Side effects:
**      sends a reply for the body part (if non-empty).
*/

static int
st_bodyend(g)
    genarg *g;
{
    sfsistat r;
    sfsistat (*fi_body) __P((SMFICTX *, unsigned char *, size_t));
    sfsistat (*fi_eom) __P((SMFICTX *));

    if (g == NULL)
        return _SMFIS_ABORT;
    r = SMFIS_CONTINUE;
    if (g->a_ctx->ctx_smfi != NULL)
    {
        if ((fi_body = g->a_ctx->ctx_smfi->xxfi_body) != NULL &&
            g->a_len > 0)
        {
            socket_t sd;
            struct timeval timeout;

            timeout.tv_sec = g->a_ctx->ctx_timeout;
            timeout.tv_usec = 0;
            sd = g->a_ctx->ctx_sd;
            r = (*fi_body)(g->a_ctx, (unsigned char *)g->a_buf,
                       g->a_len);
            if (r != SMFIS_CONTINUE &&
                sendreply(r, sd, &timeout, g->a_ctx) != MI_SUCCESS)
                return _SMFIS_ABORT;
        }
    }
    if (r == SMFIS_CONTINUE &&
        (fi_eom = g->a_ctx->ctx_smfi->xxfi_eom) != NULL)
        return (*fi_eom)(g->a_ctx);
    return r;
}

/*
**  ST_ABORTFCT -- deal with aborts
**
**  Parameters:
**      g -- generic argument structure
**
**  Returns:
**      abort or filter-specified value
*/

static int
st_abortfct(g)
    genarg *g;
{
    sfsistat (*fi_abort) __P((SMFICTX *));

    if (g == NULL)
        return _SMFIS_ABORT;
    if (g != NULL && g->a_ctx->ctx_smfi != NULL &&
        (fi_abort = g->a_ctx->ctx_smfi->xxfi_abort) != NULL)
        (void) (*fi_abort)(g->a_ctx);
    return _SMFIS_NOREPLY;
}

/*
**  TRANS_OK -- is the state transition ok?
**
**  Parameters:
**      old -- old state
**      new -- new state
**
**  Returns:
**      state transition ok
*/

static bool
trans_ok(old, new)
    int old, new;
{
    int s, n;

    s = old;
    if (s >= SIZE_NEXT_STATES)
        return false;
    do
    {
        /* is this state transition allowed? */
        if ((MI_MASK(new) & next_states[s]) != 0)
            return true;

        /*
        **  no: try next state;
        **  this works since the relevant states are ordered
        **  strict sequentially
        */

        n = s + 1;
        if (n >= SIZE_NEXT_STATES)
            return false;

        /*
        **  can we actually "skip" this state?
        **  see fix_stm() which sets this bit for those
        **  states which the filter program is not interested in
        */

        if (bitset(NX_SKIP, next_states[n]))
            s = n;
        else
            return false;
    } while (s < SIZE_NEXT_STATES);
    return false;
}

/*
**  FIX_STM -- add "skip" bits to the state transition table
**
**  Parameters:
**      ctx -- context structure
**
**  Returns:
**      None.
**
**  Side effects:
**      may change state transition table.
*/

static void
fix_stm(ctx)
    SMFICTX_PTR ctx;
{
    unsigned long fl;

    if (ctx == NULL || ctx->ctx_smfi == NULL)
        return;
    fl = ctx->ctx_pflags;
    if (bitset(SMFIP_NOCONNECT, fl))
        next_states[ST_CONN] |= NX_SKIP;
    if (bitset(SMFIP_NOHELO, fl))
        next_states[ST_HELO] |= NX_SKIP;
    if (bitset(SMFIP_NOMAIL, fl))
        next_states[ST_MAIL] |= NX_SKIP;
    if (bitset(SMFIP_NORCPT, fl))
        next_states[ST_RCPT] |= NX_SKIP;
    if (bitset(SMFIP_NOHDRS, fl))
        next_states[ST_HDRS] |= NX_SKIP;
    if (bitset(SMFIP_NOEOH, fl))
        next_states[ST_EOHS] |= NX_SKIP;
    if (bitset(SMFIP_NOBODY, fl))
        next_states[ST_BODY] |= NX_SKIP;
    if (bitset(SMFIP_NODATA, fl))
        next_states[ST_DATA] |= NX_SKIP;
    if (bitset(SMFIP_NOUNKNOWN, fl))
        next_states[ST_UNKN] |= NX_SKIP;
}

/*
**  DEC_ARGV -- split a buffer into a list of strings, NULL terminated
**
**  Parameters:
**      buf -- buffer with several strings
**      len -- length of buffer
**
**  Returns:
**      array of pointers to the individual strings
*/

static char **
dec_argv(buf, len)
    char *buf;
    size_t len;
{
    char **s;
    size_t i;
    int elem, nelem;

    nelem = 0;
    for (i = 0; i < len; i++)
    {
        if (buf[i] == '\0')
            ++nelem;
    }
    if (nelem == 0)
        return NULL;

    /* last entry is only for the name */
    s = (char **)malloc((nelem + 1) * (sizeof *s));
    if (s == NULL)
        return NULL;
    s[0] = buf;
    for (i = 0, elem = 0; i < len && elem < nelem; i++)
    {
        if (buf[i] == '\0')
        {
            ++elem;
            if (i + 1 >= len)
                s[elem] = NULL;
            else
                s[elem] = &(buf[i + 1]);
        }
    }

    /* overwrite last entry (already done above, just paranoia) */
    s[elem] = NULL;
    return s;
}

/*
**  DEC_ARG2 -- split a buffer into two strings
**
**  Parameters:
**      buf -- buffer with two strings
**      len -- length of buffer
**      s1,s2 -- pointer to result strings
**
**  Returns:
**      MI_FAILURE/MI_SUCCESS
*/

static int
dec_arg2(buf, len, s1, s2)
    char *buf;
    size_t len;
    char **s1;
    char **s2;
{
    size_t i;

    /* paranoia: check for terminating '\0' */
    if (len == 0 || buf[len - 1] != '\0')
        return MI_FAILURE;
    *s1 = buf;
    for (i = 1; i < len && buf[i] != '\0'; i++)
        continue;
    if (i >= len - 1)
        return MI_FAILURE;
    *s2 = buf + i + 1;
    return MI_SUCCESS;
}

/*
**  SENDOK -- is it ok for the filter to send stuff to the MTA?
**
**  Parameters:
**      ctx -- context structure
**      flag -- flag to check
**
**  Returns:
**      sending allowed (in current state)
*/

bool
mi_sendok(ctx, flag)
    SMFICTX_PTR ctx;
    int flag;
{
    if (ctx == NULL || ctx->ctx_smfi == NULL)
        return false;

    /* did the milter request this operation? */
    if (flag != 0 && !bitset(flag, ctx->ctx_aflags))
        return false;

    /* are we in the correct state? It must be "End of Message". */
    return ctx->ctx_state == ST_ENDM;
}

#if _FFR_WORKERS_POOL
/*
**  MI_RD_SOCKET_READY - checks if the socket is ready for read(2)
**
**  Parameters:
**      sd -- socket_t
**
**  Returns:
**      true iff socket is ready for read(2)
*/

#define MI_RD_CMD_TO  1
#define MI_RD_MAX_ERR 16

static bool
mi_rd_socket_ready (sd)
    socket_t sd;
{
    int n;
    int nerr = 0;
#if SM_CONF_POLL
    struct pollfd pfd;
#else /* SM_CONF_POLL */
    fd_set  rd_set, exc_set;
#endif /* SM_CONF_POLL */

    do
    {
#if SM_CONF_POLL
        pfd.fd = sd;
        pfd.events = POLLIN;
        pfd.revents = 0;

        n = poll(&pfd, 1, MI_RD_CMD_TO);
#else /* SM_CONF_POLL */
        struct timeval timeout;

        FD_ZERO(&rd_set);
        FD_ZERO(&exc_set);
        FD_SET(sd, &rd_set);
        FD_SET(sd, &exc_set);

        timeout.tv_sec = MI_RD_CMD_TO / 1000;
        timeout.tv_usec = 0;
        n = select(sd + 1, &rd_set, NULL, &exc_set, &timeout);
#endif /* SM_CONF_POLL */

        if (n < 0)
        {
            if (errno == EINTR)
            {
                nerr++;
                continue;
            }
            return true;
        }

        if (n == 0)
            return false;
        break;
    } while (nerr < MI_RD_MAX_ERR);
    if (nerr >= MI_RD_MAX_ERR)
        return false;

#if SM_CONF_POLL
    return (pfd.revents != 0);
#else /* SM_CONF_POLL */
    return FD_ISSET(sd, &rd_set) || FD_ISSET(sd, &exc_set);
#endif /* SM_CONF_POLL */
}
#endif /* _FFR_WORKERS_POOL */