/* Copyright (c) 2002-2018 Pigeonhole authors, see the included COPYING file

 */

/* Extension envelope

 * ------------------

 *

 * Authors: Stephan Bosch

 * Specification: RFC 5228

 * Implementation: full

 * Status: testing

 *

 */

#include "lib.h"

#include "str-sanitize.h"

#include "array.h"

#include "sieve-common.h"

#include "sieve-extensions.h"

#include "sieve-commands.h"

#include "sieve-stringlist.h"

#include "sieve-code.h"

#include "sieve-address.h"

#include "sieve-comparators.h"

#include "sieve-match-types.h"

#include "sieve-address-parts.h"

#include "sieve-message.h"

#include "sieve-validator.h"

#include "sieve-generator.h"

#include "sieve-interpreter.h"

#include "sieve-dump.h"

#include "sieve-match.h"

/*

 * Forward declarations

 */

static const struct sieve_command_def envelope_test;

const struct sieve_operation_def envelope_operation;

const struct sieve_extension_def envelope_extension;

/*

 * Extension

 */

static bool

ext_envelope_validator_load(const struct sieve_extension *ext,

          struct sieve_validator *valdtr);

static bool

ext_envelope_interpreter_load(const struct sieve_extension *ext,

            const struct sieve_runtime_env *renv,

            sieve_size_t *address);

static bool

ext_envelope_validator_validate(const struct sieve_extension *ext,

        struct sieve_validator *valdtr, void *context,

        struct sieve_ast_argument *require_arg,

        bool required);

static int

ext_envelope_interpreter_run(const struct sieve_extension *this_ext,

           const struct sieve_runtime_env *renv,

           void *context, bool deferred);

const struct sieve_extension_def envelope_extension = {

  .name = "envelope",

  .interpreter_load = ext_envelope_interpreter_load,

  .validator_load = ext_envelope_validator_load,

  SIEVE_EXT_DEFINE_OPERATION(envelope_operation)

};

const struct sieve_validator_extension

envelope_validator_extension = {

  .ext = &envelope_extension,

  .validate = ext_envelope_validator_validate

};

const struct sieve_interpreter_extension

envelope_interpreter_extension = {

  .ext_def = &envelope_extension,

  .run = ext_envelope_interpreter_run

};

static bool

ext_envelope_validator_load(const struct sieve_extension *ext,

          struct sieve_validator *valdtr)

{

  /* Register new test */

  sieve_validator_register_command(valdtr, ext, &envelope_test);

  sieve_validator_extension_register(valdtr, ext,

             &envelope_validator_extension, NULL);

  return TRUE;

}

static bool

ext_envelope_interpreter_load(const struct sieve_extension *ext,

            const struct sieve_runtime_env *renv,

            sieve_size_t *address ATTR_UNUSED)

{

  sieve_interpreter_extension_register(renv->interp, ext,

               &envelope_interpreter_extension,

               NULL);

  return TRUE;

}

static bool

ext_envelope_validator_validate(const struct sieve_extension *ext,

        struct sieve_validator *valdtr,

        void *context ATTR_UNUSED,

        struct sieve_ast_argument *require_arg,

        bool required)

{

  if (required) {

    enum sieve_compile_flags flags =

      sieve_validator_compile_flags(valdtr);

    if ((flags & SIEVE_COMPILE_FLAG_NO_ENVELOPE) != 0) {

      sieve_argument_validate_error(

        valdtr, require_arg,

        "the %s extension cannot be used in this context "

        "(needs access to message envelope)",

        sieve_extension_name(ext));

      return FALSE;

    }

  }

  return TRUE;

}

static int

ext_envelope_interpreter_run(const struct sieve_extension *ext,

           const struct sieve_runtime_env *renv,

           void *context ATTR_UNUSED, bool deferred)

{

  const struct sieve_execute_env *eenv = renv->exec_env;

  if ((eenv->flags & SIEVE_EXECUTE_FLAG_NO_ENVELOPE) != 0) {

    if (!deferred) {

      sieve_runtime_error(

        renv, NULL,

        "the %s extension cannot be used in this context "

        "(needs access to message envelope)",

        sieve_extension_name(ext));

    }

    return SIEVE_EXEC_FAILURE;

  }

  return SIEVE_EXEC_OK;

}

/*

 * Envelope test

 *

 * Syntax

 *   envelope [COMPARATOR] [ADDRESS-PART] [MATCH-TYPE]

 *     <envelope-part: string-list> <key-list: string-list>

 */

static bool

tst_envelope_registered(struct sieve_validator *valdtr,

      const struct sieve_extension *ext,

      struct sieve_command_registration *cmd_reg);

static bool

tst_envelope_validate(struct sieve_validator *valdtr,

          struct sieve_command *tst);

static bool

tst_envelope_generate(const struct sieve_codegen_env *cgenv,

          struct sieve_command *ctx);

static const struct sieve_command_def envelope_test = {

  .identifier = "envelope",

  .type = SCT_TEST,

  .positional_args= 2,

  .subtests = 0,

  .block_allowed = FALSE,

  .block_required = FALSE,

  .registered = tst_envelope_registered,

  .validate = tst_envelope_validate,

  .generate = tst_envelope_generate

};

/*

 * Envelope operation

 */

static bool

ext_envelope_operation_dump(const struct sieve_dumptime_env *denv,

          sieve_size_t *address);

static int

ext_envelope_operation_execute(const struct sieve_runtime_env *renv,

             sieve_size_t *address);

const struct sieve_operation_def envelope_operation = {

  .mnemonic = "ENVELOPE",

  .ext_def = &envelope_extension,

  .dump = ext_envelope_operation_dump,

  .execute = ext_envelope_operation_execute

};

/*

 * Envelope parts

 *

 * FIXME: not available to extensions

 */

struct sieve_envelope_part {

  const char *identifier;

  const struct smtp_address *const *(*get_addresses)

    (const struct sieve_runtime_env *renv);

  const char *const *(*get_values)

    (const struct sieve_runtime_env *renv);

};

static const struct smtp_address *const *

_from_part_get_addresses(const struct sieve_runtime_env *renv);

static const char *const *

_from_part_get_values(const struct sieve_runtime_env *renv);

static const struct smtp_address *const *

_to_part_get_addresses(const struct sieve_runtime_env *renv);

static const char *const *

_to_part_get_values(const struct sieve_runtime_env *renv);

static const char *const *

_auth_part_get_values(const struct sieve_runtime_env *renv);

static const struct sieve_envelope_part _from_part = {

  "from",

  _from_part_get_addresses,

  _from_part_get_values,

};

static const struct sieve_envelope_part _to_part = {

  "to",

  _to_part_get_addresses,

  _to_part_get_values,

};

static const struct sieve_envelope_part _auth_part = {

  "auth",

  NULL,

  _auth_part_get_values,

};

static const struct sieve_envelope_part *_envelope_parts[] = {

  /* Required */

  &_from_part, &_to_part,

  /* Non-standard */

  &_auth_part

};

static unsigned int _envelope_part_count = N_ELEMENTS(_envelope_parts);

static const struct sieve_envelope_part *

_envelope_part_find(const char *identifier)

{

  unsigned int i;

  for (i = 0; i < _envelope_part_count; i++) {

    if (strcasecmp(_envelope_parts[i]->identifier,

             identifier) == 0)

      return _envelope_parts[i];

  }

  return NULL;

}

/* Envelope parts implementation */

static const struct smtp_address *const *

_from_part_get_addresses(const struct sieve_runtime_env *renv)

{

  ARRAY(const struct smtp_address *) envelope_values;

  const struct smtp_address *address =

    sieve_message_get_sender(renv->msgctx);

  t_array_init(&envelope_values, 2);

  if (address == NULL)

    address = smtp_address_create_temp(NULL, NULL);

  array_append(&envelope_values, &address, 1);

  (void)array_append_space(&envelope_values);

  return array_idx(&envelope_values, 0);

}

static const char *const *

_from_part_get_values(const struct sieve_runtime_env *renv)

{

  ARRAY(const char *)envelope_values;

  const struct smtp_address *address =

    sieve_message_get_sender(renv->msgctx);

  const char *value;

  t_array_init(&envelope_values, 2);

  value = "";

  if (!smtp_address_isnull(address))

    value = smtp_address_encode(address);

  array_append(&envelope_values, &value, 1);

  (void)array_append_space(&envelope_values);

  return array_idx(&envelope_values, 0);

}

static const struct smtp_address *const *

_to_part_get_addresses(const struct sieve_runtime_env *renv)

{

  ARRAY(const struct smtp_address *) envelope_values;

  const struct smtp_address *address =

    sieve_message_get_orig_recipient(renv->msgctx);

  if (address != NULL && address->localpart != NULL) {

    t_array_init(&envelope_values, 2);

    array_append(&envelope_values, &address, 1);

    (void)array_append_space(&envelope_values);

    return array_idx(&envelope_values, 0);

  }

  return NULL;

}

static const char *const *

_to_part_get_values(const struct sieve_runtime_env *renv)

{

  ARRAY(const char *) envelope_values;

  const struct smtp_address *address =

    sieve_message_get_orig_recipient(renv->msgctx);

  t_array_init(&envelope_values, 2);

  if (address != NULL && address->localpart != NULL) {

    const char *value = smtp_address_encode(address);

    array_append(&envelope_values, &value, 1);

  }

  (void)array_append_space(&envelope_values);

  return array_idx(&envelope_values, 0);

}

static const char *const *

_auth_part_get_values(const struct sieve_runtime_env *renv)

{

  const struct sieve_execute_env *eenv = renv->exec_env;

  ARRAY(const char *) envelope_values;

  t_array_init(&envelope_values, 2);

  if (eenv->msgdata->auth_user != NULL)

    array_append(&envelope_values, &eenv->msgdata->auth_user, 1);

  (void)array_append_space(&envelope_values);

  return array_idx(&envelope_values, 0);

}

/*

 * Envelope address list

 */

/* Forward declarations */

static int

sieve_envelope_address_list_next_string_item(struct sieve_stringlist *_strlist,

               string_t **str_r);

static int

sieve_envelope_address_list_next_item(struct sieve_address_list *_addrlist,

              struct smtp_address *addr_r,

              string_t **unparsed_r);

static void

sieve_envelope_address_list_reset(struct sieve_stringlist *_strlist);

/* Stringlist object */

struct sieve_envelope_address_list {

  struct sieve_address_list addrlist;

  struct sieve_stringlist *env_parts;

  const struct smtp_address *const *cur_addresses;

  const char *const *cur_values;

  int value_index;

};

static struct sieve_address_list *

sieve_envelope_address_list_create(const struct sieve_runtime_env *renv,

           struct sieve_stringlist *env_parts)

{

  struct sieve_envelope_address_list *addrlist;

  addrlist = t_new(struct sieve_envelope_address_list, 1);

  addrlist->addrlist.strlist.runenv = renv;

  addrlist->addrlist.strlist.exec_status = SIEVE_EXEC_OK;

  addrlist->addrlist.strlist.next_item =

    sieve_envelope_address_list_next_string_item;

  addrlist->addrlist.strlist.reset = sieve_envelope_address_list_reset;

  addrlist->addrlist.next_item = sieve_envelope_address_list_next_item;

  addrlist->env_parts = env_parts;

  return &addrlist->addrlist;

}

static int

sieve_envelope_address_list_next_item(struct sieve_address_list *_addrlist,

              struct smtp_address *addr_r,

              string_t **unparsed_r)

{

  struct sieve_envelope_address_list *addrlist =

    (struct sieve_envelope_address_list *)_addrlist;

  const struct sieve_runtime_env *renv = _addrlist->strlist.runenv;

  if (addr_r != NULL)

    smtp_address_init(addr_r, NULL, NULL);

  if (unparsed_r != NULL) *unparsed_r = NULL;

  while (addrlist->cur_addresses == NULL &&

         addrlist->cur_values == NULL) {

    const struct sieve_envelope_part *epart;

    string_t *envp_item = NULL;

    int ret;

    /* Read next header value from source list */

    if ((ret = sieve_stringlist_next_item(addrlist->env_parts,

                  &envp_item)) <= 0)

      return ret;

    if (_addrlist->strlist.trace) {

      sieve_runtime_trace(

        _addrlist->strlist.runenv, 0,

        "getting '%s' part from message envelope",

        str_sanitize(str_c(envp_item), 80));

    }

    if ((epart=_envelope_part_find(str_c(envp_item))) != NULL) {

      addrlist->value_index = 0;

      if (epart->get_addresses != NULL) {

        /* Field contains addresses */

        addrlist->cur_addresses =

          epart->get_addresses(renv);

        /* Drop empty list */

        if (addrlist->cur_addresses != NULL &&

            addrlist->cur_addresses[0] == NULL)

          addrlist->cur_addresses = NULL;

      }

      if (addrlist->cur_addresses == NULL &&

          epart->get_values != NULL) {

        /* Field contains something else */

        addrlist->cur_values = epart->get_values(renv);

        /* Drop empty list */

        if (addrlist->cur_values != NULL &&

            addrlist->cur_values[0] == NULL)

          addrlist->cur_values = NULL;

      }

    }

  }

  /* Return next item */

  if (addrlist->cur_addresses != NULL) {

    const struct smtp_address *addr =

      addrlist->cur_addresses[addrlist->value_index];

    if (addr->localpart == NULL) {

      /* Null path <> */

      if (unparsed_r != NULL)

        *unparsed_r = t_str_new_const("", 0);

    } else {

      if (addr_r != NULL)

        *addr_r = *addr;

    }

    /* Advance to next value */

    addrlist->value_index++;

    if (addrlist->cur_addresses[addrlist->value_index] == NULL) {

      addrlist->cur_addresses = NULL;

      addrlist->value_index = 0;

    }

  } else {

    if (unparsed_r != NULL) {

      const char *value =

        addrlist->cur_values[addrlist->value_index];

      *unparsed_r = t_str_new_const(value, strlen(value));

    }

    /* Advance to next value */

    addrlist->value_index++;

    if (addrlist->cur_values[addrlist->value_index] == NULL) {

      addrlist->cur_values = NULL;

      addrlist->value_index = 0;

    }

  }

  return 1;

}

static int

sieve_envelope_address_list_next_string_item(struct sieve_stringlist *_strlist,

               string_t **str_r)

{

  struct sieve_address_list *addrlist =

    (struct sieve_address_list *)_strlist;

  struct smtp_address addr;

  int ret;

  if ((ret=sieve_envelope_address_list_next_item(addrlist, &addr,

                   str_r)) <= 0)

    return ret;

  if (addr.localpart != NULL) {

    const char *addr_str = smtp_address_encode(&addr);

    if (str_r != NULL)

      *str_r = t_str_new_const(addr_str, strlen(addr_str));

  }

  return 1;

}

static void

sieve_envelope_address_list_reset(struct sieve_stringlist *_strlist)

{

  struct sieve_envelope_address_list *addrlist =

    (struct sieve_envelope_address_list *)_strlist;

  sieve_stringlist_reset(addrlist->env_parts);

  addrlist->cur_addresses = NULL;

  addrlist->cur_values = NULL;

  addrlist->value_index = 0;

}

/*

 * Command Registration

 */

static bool

tst_envelope_registered(struct sieve_validator *valdtr,

      const struct sieve_extension *ext ATTR_UNUSED,

      struct sieve_command_registration *cmd_reg)

{

  /* The order of these is not significant */

  sieve_comparators_link_tag(valdtr, cmd_reg, SIEVE_MATCH_OPT_COMPARATOR);

  sieve_match_types_link_tags(valdtr, cmd_reg, SIEVE_MATCH_OPT_MATCH_TYPE);

  sieve_address_parts_link_tags(valdtr, cmd_reg, SIEVE_AM_OPT_ADDRESS_PART);

  return TRUE;

}

/*

 * Validation

 */

static int

_envelope_part_is_supported(void *context, struct sieve_ast_argument *arg)

{

  const struct sieve_envelope_part **not_address =

    (const struct sieve_envelope_part **) context;

  if (sieve_argument_is_string_literal(arg)) {

    const struct sieve_envelope_part *epart;

    if ((epart=_envelope_part_find(

      sieve_ast_strlist_strc(arg))) != NULL) {

      if (epart->get_addresses == NULL) {

        if (*not_address == NULL)

          *not_address = epart;

      }

      return 1;

    }

    return 0;

  }

  return 1; /* Can't check at compile time */

}

static bool

tst_envelope_validate(struct sieve_validator *valdtr, struct sieve_command *tst)

{

  struct sieve_ast_argument *arg = tst->first_positional;

  struct sieve_ast_argument *epart;

  struct sieve_comparator cmp_default =

    SIEVE_COMPARATOR_DEFAULT(i_ascii_casemap_comparator);

  struct sieve_match_type mcht_default =

    SIEVE_MATCH_TYPE_DEFAULT(is_match_type);

  const struct sieve_envelope_part *not_address = NULL;

  if (!sieve_validate_positional_argument(valdtr, tst, arg,

            "envelope part", 1,

            SAAT_STRING_LIST)) {

    return FALSE;

  }

  if (!sieve_validator_argument_activate(valdtr, tst, arg, FALSE))

    return FALSE;

  /* Check whether supplied envelope parts are supported

   *   FIXME: verify dynamic envelope parts at runtime

   */

  epart = arg;

  if (sieve_ast_stringlist_map(&epart, &not_address,

             _envelope_part_is_supported) <= 0) {

    i_assert(epart != NULL);

    sieve_argument_validate_error(

      valdtr, epart,

      "specified envelope part '%s' is not supported by the envelope test",

      str_sanitize(sieve_ast_strlist_strc(epart), 64));

    return FALSE;

  }

  if (not_address != NULL) {

    struct sieve_ast_argument *addrp_arg =

      sieve_command_find_argument(tst, &address_part_tag);

    if (addrp_arg != NULL) {

      sieve_argument_validate_error(

        valdtr, addrp_arg,

        "address part ':%s' specified while non-address envelope part '%s' "

        "is tested with the envelope test",

      sieve_ast_argument_tag(addrp_arg),

                 not_address->identifier);

      return FALSE;

    }

  }

  arg = sieve_ast_argument_next(arg);

  if (!sieve_validate_positional_argument(valdtr, tst, arg, "key list", 2,

            SAAT_STRING_LIST))

    return FALSE;

  if (!sieve_validator_argument_activate(valdtr, tst, arg, FALSE))

    return FALSE;

  /* Validate the key argument to a specified match type */

  return sieve_match_type_validate(valdtr, tst, arg,

           &mcht_default, &cmp_default);

}

/*

 * Code generation

 */

static bool

tst_envelope_generate(const struct sieve_codegen_env *cgenv,

          struct sieve_command *cmd)

{

  (void)sieve_operation_emit(cgenv->sblock, cmd->ext,

           &envelope_operation);

  /* Generate arguments */

  if (!sieve_generate_arguments(cgenv, cmd, NULL))

    return FALSE;

  return TRUE;

}

/*

 * Code dump

 */

static bool

ext_envelope_operation_dump(const struct sieve_dumptime_env *denv,

          sieve_size_t *address)

{

  sieve_code_dumpf(denv, "ENVELOPE");

  sieve_code_descend(denv);

  /* Handle any optional arguments */

  if (sieve_addrmatch_opr_optional_dump(denv, address, NULL) != 0)

    return FALSE;

  return (sieve_opr_stringlist_dump(denv, address, "envelope part") &&

    sieve_opr_stringlist_dump(denv, address, "key list"));

}

/*

 * Interpretation

 */

static int

ext_envelope_operation_execute(const struct sieve_runtime_env *renv,

             sieve_size_t *address)

{

  struct sieve_comparator cmp =

    SIEVE_COMPARATOR_DEFAULT(i_ascii_casemap_comparator);

  struct sieve_match_type mcht =

    SIEVE_MATCH_TYPE_DEFAULT(is_match_type);

  struct sieve_address_part addrp =

    SIEVE_ADDRESS_PART_DEFAULT(all_address_part);

  struct sieve_stringlist *env_part_list, *value_list, *key_list;

  struct sieve_address_list *addr_list;

  int match, ret;

  /*

   * Read operands

   */

  /* Read optional operands */

  if (sieve_addrmatch_opr_optional_read(renv, address, NULL, &ret,

                &addrp, &mcht, &cmp) < 0)

    return ret;

  /* Read envelope-part */

  if ((ret = sieve_opr_stringlist_read(renv, address, "envelope-part",

               &env_part_list)) <= 0)

    return ret;

  /* Read key-list */

  if ((ret = sieve_opr_stringlist_read(renv, address, "key-list",

               &key_list)) <= 0)

    return ret;

  /*

   * Perform test

   */

  sieve_runtime_trace(renv, SIEVE_TRLVL_TESTS, "envelope test");

  /* Create value stringlist */

  addr_list = sieve_envelope_address_list_create(renv, env_part_list);

  value_list = sieve_address_part_stringlist_create(renv, &addrp,

                addr_list);

  /* Perform match */

  if ((match = sieve_match(renv, &mcht, &cmp,

         value_list, key_list, &ret)) < 0)

    return ret;

  /* Set test result for subsequent conditional jump */

  sieve_interpreter_set_test_result(renv->interp, match > 0);

  return SIEVE_EXEC_OK;

}