/src/haproxy/src/acl.c

Source
/*
 * ACL management functions.
 *
 * Copyright 2000-2013 Willy Tarreau <w@1wt.eu>
 *
 * 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.
 *
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>

#include <import/ebsttree.h>

#include <haproxy/acl.h>
#include <haproxy/api.h>
#include <haproxy/arg.h>
#include <haproxy/auth.h>
#include <haproxy/errors.h>
#include <haproxy/global.h>
#include <haproxy/list.h>
#include <haproxy/pattern.h>
#include <haproxy/proxy-t.h>
#include <haproxy/sample.h>
#include <haproxy/stick_table.h>
#include <haproxy/tools.h>
#include <haproxy/cfgparse.h>

/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
  .list = LIST_HEAD_INIT(acl_keywords.list)
};

/* input values are 0 or 3, output is the same */
static inline enum acl_test_res pat2acl(struct pattern *pat)
{
  if (pat)
    return ACL_TEST_PASS;
  else
    return ACL_TEST_FAIL;
}

/*
 * Registers the ACL keyword list <kwl> as a list of valid keywords for next
 * parsing sessions.
 */
void acl_register_keywords(struct acl_kw_list *kwl)
{
  LIST_APPEND(&acl_keywords.list, &kwl->list);
}

/*
 * Unregisters the ACL keyword list <kwl> from the list of valid keywords.
 */
void acl_unregister_keywords(struct acl_kw_list *kwl)
{
  LIST_DELETE(&kwl->list);
  LIST_INIT(&kwl->list);
}

/* Return a pointer to the ACL <name> within the list starting at <head>, or
 * NULL if not found.
 */
struct acl *find_acl_by_name(const char *name, struct list *head)
{
  struct acl *acl;
  list_for_each_entry(acl, head, list) {
    if (strcmp(acl->name, name) == 0)
      return acl;
  }
  return NULL;
}

/* Return a pointer to the ACL keyword <kw>, or NULL if not found. Note that if
 * <kw> contains an opening parenthesis or a comma, only the left part of it is
 * checked.
 */
struct acl_keyword *find_acl_kw(const char *kw)
{
  int index;
  const char *kwend;
  struct acl_kw_list *kwl;

  kwend = kw;
  while (is_idchar(*kwend))
    kwend++;

  list_for_each_entry(kwl, &acl_keywords.list, list) {
    for (index = 0; kwl->kw[index].kw != NULL; index++) {
      if ((strncmp(kwl->kw[index].kw, kw, kwend - kw) == 0) &&
          kwl->kw[index].kw[kwend-kw] == 0)
        return &kwl->kw[index];
    }
  }
  return NULL;
}

static struct acl_expr *prune_acl_expr(struct acl_expr *expr)
{
  struct arg *arg;

  pattern_prune(&expr->pat);

  for (arg = expr->smp->arg_p; arg; arg++) {
    if (arg->type == ARGT_STOP)
      break;
    if (arg->type == ARGT_STR || arg->unresolved) {
      chunk_destroy(&arg->data.str);
      arg->unresolved = 0;
    }
  }

  release_sample_expr(expr->smp);

  return expr;
}

/* Parse an ACL expression starting at <args>[0], and return it. If <err> is
 * not NULL, it will be filled with a pointer to an error message in case of
 * error. This pointer must be freeable or NULL. <al> is an arg_list serving
 * as a list head to report missing dependencies. It may be NULL if such
 * dependencies are not allowed.
 *
 * Right now, the only accepted syntax is :
 * <subject> [<value>...]
 */
struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *al,
                                const char *file, int line)
{
  __label__ out_return, out_free_expr;
  struct acl_expr *expr;
  struct acl_keyword *aclkw;
  int refflags, patflags;
  const char *arg;
  struct sample_expr *smp = NULL;
  int idx = 0;
  char *ckw = NULL;
  const char *endt;
  int cur_type;
  int nbargs;
  int operator = STD_OP_EQ;
  int op;
  int contain_colon, have_dot;
  const char *dot;
  signed long long value, minor;
  /* The following buffer contain two numbers, a ':' separator and the final \0. */
  char buffer[NB_LLMAX_STR + 1 + NB_LLMAX_STR + 1];
  int is_loaded, match_forced;
  int unique_id;
  char *error;
  struct pat_ref *ref;
  struct pattern_expr *pattern_expr;
  int load_as_map = 0;
  int acl_conv_found = 0;

  /* First, we look for an ACL keyword. And if we don't find one, then
   * we look for a sample fetch expression starting with a sample fetch
   * keyword.
   */

  if (al) {
    al->ctx  = ARGC_ACL;   // to report errors while resolving args late
    al->conv = NULL;
  }

  aclkw = find_acl_kw(args[0]);
  if (aclkw) {
    /* OK we have a real ACL keyword */

    if (al)
      al->kw = aclkw->kw;

    /* build new sample expression for this ACL */
    smp = calloc(1, sizeof(*smp));
    if (!smp) {
      memprintf(err, "out of memory when parsing ACL expression");
      goto out_return;
    }
    LIST_INIT(&(smp->conv_exprs));
    smp->fetch = aclkw->smp;
    smp->arg_p = empty_arg_list;

    /* look for the beginning of the subject arguments */
    for (arg = args[0]; is_idchar(*arg); arg++)
      ;

    /* At this point, we have :
     *   - args[0] : beginning of the keyword
     *   - arg     : end of the keyword, first character not part of keyword
     */
    nbargs = make_arg_list(arg, -1, smp->fetch->arg_mask, &smp->arg_p,
                           err, &endt, NULL, al);
    if (nbargs < 0) {
      /* note that make_arg_list will have set <err> here */
      memprintf(err, "ACL keyword '%s' : %s", aclkw->kw, *err);
      goto out_free_smp;
    }

    if (!smp->arg_p) {
      smp->arg_p = empty_arg_list;
    }
    else if (smp->fetch->val_args && !smp->fetch->val_args(smp->arg_p, err)) {
      /* invalid keyword argument, error must have been
       * set by val_args().
       */
      memprintf(err, "in argument to '%s', %s", aclkw->kw, *err);
      goto out_free_smp;
    }

    /* look for the beginning of the converters list. Those directly attached
     * to the ACL keyword are found just after the comma.
     * If we find any converter, then we don't use the ACL keyword's match
     * anymore but the one related to the converter's output type.
     */
    if (!sample_parse_expr_cnv((char **)args, NULL, NULL, err, al, file, line, smp, endt)) {
      if (err)
        memprintf(err, "ACL keyword '%s' : %s", aclkw->kw, *err);
      goto out_free_smp;
    }
    acl_conv_found = !LIST_ISEMPTY(&smp->conv_exprs);
  }
  else {
    /* This is not an ACL keyword, so we hope this is a sample fetch
     * keyword that we're going to transparently use as an ACL. If
     * so, we retrieve a completely parsed expression with args and
     * convs already done.
     */
    smp = sample_parse_expr((char **)args, &idx, file, line, err, al, NULL);
    if (!smp) {
      memprintf(err, "%s in ACL expression '%s'", *err, *args);
      goto out_return;
    }
  }

  /* get last effective output type for smp */
  cur_type = smp_expr_output_type(smp);

  expr = calloc(1, sizeof(*expr));
  if (!expr) {
    memprintf(err, "out of memory when parsing ACL expression");
    goto out_free_smp;
  }

  pattern_init_head(&expr->pat);

  expr->pat.expect_type = cur_type;
  expr->smp             = smp;
  expr->kw              = smp->fetch->kw;
  smp = NULL; /* don't free it anymore */

  if (aclkw && !acl_conv_found) {
    expr->kw = aclkw->kw;
    expr->pat.parse  = aclkw->parse  ? aclkw->parse  : pat_parse_fcts[aclkw->match_type];
    expr->pat.index  = aclkw->index  ? aclkw->index  : pat_index_fcts[aclkw->match_type];
    expr->pat.match  = aclkw->match  ? aclkw->match  : pat_match_fcts[aclkw->match_type];
    expr->pat.prune  = aclkw->prune  ? aclkw->prune  : pat_prune_fcts[aclkw->match_type];
  }

  if (!expr->pat.parse) {
    /* Parse/index/match functions depend on the expression type,
     * so we have to map them now. Some types can be automatically
     * converted.
     */
    switch (cur_type) {
    case SMP_T_BOOL:
      expr->pat.parse = pat_parse_fcts[PAT_MATCH_BOOL];
      expr->pat.index = pat_index_fcts[PAT_MATCH_BOOL];
      expr->pat.match = pat_match_fcts[PAT_MATCH_BOOL];
      expr->pat.prune = pat_prune_fcts[PAT_MATCH_BOOL];
      expr->pat.expect_type = pat_match_types[PAT_MATCH_BOOL];
      break;
    case SMP_T_SINT:
      expr->pat.parse = pat_parse_fcts[PAT_MATCH_INT];
      expr->pat.index = pat_index_fcts[PAT_MATCH_INT];
      expr->pat.match = pat_match_fcts[PAT_MATCH_INT];
      expr->pat.prune = pat_prune_fcts[PAT_MATCH_INT];
      expr->pat.expect_type = pat_match_types[PAT_MATCH_INT];
      break;
    case SMP_T_ADDR:
    case SMP_T_IPV4:
    case SMP_T_IPV6:
      expr->pat.parse = pat_parse_fcts[PAT_MATCH_IP];
      expr->pat.index = pat_index_fcts[PAT_MATCH_IP];
      expr->pat.match = pat_match_fcts[PAT_MATCH_IP];
      expr->pat.prune = pat_prune_fcts[PAT_MATCH_IP];
      expr->pat.expect_type = pat_match_types[PAT_MATCH_IP];
      break;
    case SMP_T_STR:
      expr->pat.parse = pat_parse_fcts[PAT_MATCH_STR];
      expr->pat.index = pat_index_fcts[PAT_MATCH_STR];
      expr->pat.match = pat_match_fcts[PAT_MATCH_STR];
      expr->pat.prune = pat_prune_fcts[PAT_MATCH_STR];
      expr->pat.expect_type = pat_match_types[PAT_MATCH_STR];
      break;
    }
  }

  /* Additional check to protect against common mistakes */
  if (expr->pat.parse && cur_type != SMP_T_BOOL && !*args[1]) {
    ha_warning("parsing acl keyword '%s' :\n"
         "  no pattern to match against were provided, so this ACL will never match.\n"
         "  If this is what you intended, please add '--' to get rid of this warning.\n"
         "  If you intended to match only for existence, please use '-m found'.\n"
         "  If you wanted to force an int to match as a bool, please use '-m bool'.\n"
         "\n",
         args[0]);
  }

  args++;

  /* check for options before patterns. Supported options are :
   *   -i : ignore case for all patterns by default
   *   -f : read patterns from those files
   *   -m : force matching method (must be used before -f)
   *   -M : load the file as map file
   *   -u : force the unique id of the acl
   *   -- : everything after this is not an option
   */
  refflags = PAT_REF_ACL;
  patflags = 0;
  is_loaded = 0;
  match_forced = 0;
  unique_id = -1;
  while (**args == '-') {
    if (strcmp(*args, "-i") == 0)
      patflags |= PAT_MF_IGNORE_CASE;
    else if (strcmp(*args, "-n") == 0)
      patflags |= PAT_MF_NO_DNS;
    else if (strcmp(*args, "-u") == 0) {
      unique_id = strtol(args[1], &error, 10);
      if (*error != '\0') {
        memprintf(err, "the argument of -u must be an integer");
        goto out_free_expr;
      }

      /* Check if this id is really unique. */
      if (pat_ref_lookupid(unique_id)) {
        memprintf(err, "the id is already used");
        goto out_free_expr;
      }

      args++;
    }
    else if (strcmp(*args, "-f") == 0) {
      if (!expr->pat.parse) {
        memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
        goto out_free_expr;
      }

      if (!pattern_read_from_file(&expr->pat, refflags, args[1], patflags, load_as_map, err, file, line))
        goto out_free_expr;
      is_loaded = 1;
      args++;
    }
    else if (strcmp(*args, "-m") == 0) {
      int idx;

      if (is_loaded) {
        memprintf(err, "'-m' must only be specified before patterns and files in parsing ACL expression");
        goto out_free_expr;
      }
      if (match_forced) {
        memprintf(err, "only one explicit matching method can be defined with '-m' parameter."
            " if migrating from an old version, just keep the last one");
        goto out_free_expr;
      }

      idx = pat_find_match_name(args[1]);
      if (idx < 0) {
        memprintf(err, "unknown matching method '%s' when parsing ACL expression", args[1]);
        goto out_free_expr;
      }

      /* Note: -m found is always valid, bool/int are compatible, str/bin/reg/len are compatible */
      if (idx != PAT_MATCH_FOUND && !sample_casts[cur_type][pat_match_types[idx]]) {
        memprintf(err, "matching method '%s' cannot be used with fetch keyword '%s'", args[1], expr->kw);
        goto out_free_expr;
      }
      expr->pat.parse = pat_parse_fcts[idx];
      expr->pat.index = pat_index_fcts[idx];
      expr->pat.match = pat_match_fcts[idx];
      expr->pat.prune = pat_prune_fcts[idx];
      expr->pat.expect_type = pat_match_types[idx];
      match_forced = 1;
      args++;
    }
    else if (strcmp(*args, "-M") == 0) {
      refflags |= PAT_REF_MAP;
      load_as_map = 1;
    }
    else if (strcmp(*args, "--") == 0) {
      args++;
      break;
    }
    else {
      memprintf(err, "'%s' is not a valid ACL option. Please use '--' before any pattern beginning with a '-'", args[0]);
      goto out_free_expr;
      break;
    }
    args++;
  }

  if (!expr->pat.parse) {
    memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
    goto out_free_expr;
  }

  if (aclkw) {
    if (((aclkw->match_type == PAT_MATCH_BEG || aclkw->match_type == PAT_MATCH_DIR || aclkw->match_type == PAT_MATCH_DOM ||
          aclkw->match_type == PAT_MATCH_DOM || aclkw->match_type == PAT_MATCH_END || aclkw->match_type == PAT_MATCH_LEN ||
          aclkw->match_type == PAT_MATCH_REG || aclkw->match_type == PAT_MATCH_SUB) &&
         expr->pat.match != pat_match_fcts[aclkw->match_type]) ||
        (aclkw->match && expr->pat.match != aclkw->match))
      ha_warning("parsing [%s:%d] : original matching method '%s' was overwritten and will not be applied as expected.\n",
           file, line, aclkw->kw);
  }

  /* Create displayed reference */
  snprintf(trash.area, trash.size, "acl '%s' file '%s' line %d",
     expr->kw, file, line);
  trash.area[trash.size - 1] = '\0';

  /* Create new pattern reference. */
  ref = pat_ref_newid(unique_id, trash.area, PAT_REF_ACL);
  if (!ref) {
    memprintf(err, "memory error");
    goto out_free_expr;
  }

  /* Create new pattern expression associated to this reference. */
  pattern_expr = pattern_new_expr(&expr->pat, ref, patflags, err, NULL);
  if (!pattern_expr)
    goto out_free_expr;

  /* now parse all patterns */
  while (**args) {
    arg = *args;

    /* Compatibility layer. Each pattern can parse only one string per pattern,
     * but the pat_parser_int() and pat_parse_dotted_ver() parsers were need
     * optionally two operators. The first operator is the match method: eq,
     * le, lt, ge and gt. pat_parse_int() and pat_parse_dotted_ver() functions
     * can have a compatibility syntax based on ranges:
     *
     * pat_parse_int():
     *
     *   "eq x" -> "x" or "x:x"
     *   "le x" -> ":x"
     *   "lt x" -> ":y" (with y = x - 1)
     *   "ge x" -> "x:"
     *   "gt x" -> "y:" (with y = x + 1)
     *
     * pat_parse_dotted_ver():
     *
     *   "eq x.y" -> "x.y" or "x.y:x.y"
     *   "le x.y" -> ":x.y"
     *   "lt x.y" -> ":w.z" (with w.z = x.y - 1)
     *   "ge x.y" -> "x.y:"
     *   "gt x.y" -> "w.z:" (with w.z = x.y + 1)
     *
     * If y is not present, assume that is "0".
     *
     * The syntax eq, le, lt, ge and gt are proper to the acl syntax. The
     * following block of code detect the operator, and rewrite each value
     * in parsable string.
     */
    if (expr->pat.parse == pat_parse_int ||
        expr->pat.parse == pat_parse_dotted_ver) {
      /* Check for operator. If the argument is operator, memorise it and
       * continue to the next argument.
       */
      op = get_std_op(arg);
      if (op != -1) {
        operator = op;
        args++;
        continue;
      }

      /* Check if the pattern contain ':' or '-' character. */
      contain_colon = (strchr(arg, ':') || strchr(arg, '-'));

      /* If the pattern contain ':' or '-' character, give it to the parser as is.
       * If no contain ':' and operator is STD_OP_EQ, give it to the parser as is.
       * In other case, try to convert the value according with the operator.
       */
      if (!contain_colon && operator != STD_OP_EQ) {
        /* Search '.' separator. */
        dot = strchr(arg, '.');
        if (!dot) {
          have_dot = 0;
          minor = 0;
          dot = arg + strlen(arg);
        }
        else
          have_dot = 1;

        /* convert the integer minor part for the pat_parse_dotted_ver() function. */
        if (expr->pat.parse == pat_parse_dotted_ver && have_dot) {
          if (strl2llrc(dot+1, strlen(dot+1), &minor) != 0) {
            memprintf(err, "'%s' is neither a number nor a supported operator", arg);
            goto out_free_expr;
          }
          if (minor >= 65536) {
            memprintf(err, "'%s' contains too large a minor value", arg);
            goto out_free_expr;
          }
        }

        /* convert the integer value for the pat_parse_int() function, and the
         * integer major part for the pat_parse_dotted_ver() function.
         */
        if (strl2llrc(arg, dot - arg, &value) != 0) {
          memprintf(err, "'%s' is neither a number nor a supported operator", arg);
          goto out_free_expr;
        }
        if (expr->pat.parse == pat_parse_dotted_ver)  {
          if (value >= 65536) {
            memprintf(err, "'%s' contains too large a major value", arg);
            goto out_free_expr;
          }
          value = (value << 16) | (minor & 0xffff);
        }

        switch (operator) {

        case STD_OP_EQ: /* this case is not possible. */
          memprintf(err, "internal error");
          goto out_free_expr;

        case STD_OP_GT:
          value++; /* gt = ge + 1 */
          __fallthrough;

        case STD_OP_GE:
          if (expr->pat.parse == pat_parse_int)
            snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, "%lld:", value);
          else
            snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, "%lld.%lld:",
                     value >> 16, value & 0xffff);
          arg = buffer;
          break;

        case STD_OP_LT:
          value--; /* lt = le - 1 */
          __fallthrough;

        case STD_OP_LE:
          if (expr->pat.parse == pat_parse_int)
            snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, ":%lld", value);
          else
            snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, ":%lld.%lld",
                     value >> 16, value & 0xffff);
          arg = buffer;
          break;
        }
      }
    }

    /* Add sample to the reference, and try to compile it fior each pattern
     * using this value.
     */
    if (!pat_ref_add(ref, arg, NULL, err))
      goto out_free_expr;

    if (global.mode & MODE_DIAG) {
      if (strcmp(arg, "&&") == 0 || strcmp(arg, "and") == 0 ||
          strcmp(arg, "||") == 0 ||  strcmp(arg, "or") == 0)
        ha_diag_warning("parsing [%s:%d] : pattern '%s' looks like a failed attempt at using an operator inside a pattern list\n", file, line, arg);
      else if (strcmp(arg, "#") == 0 || strcmp(arg, "//") == 0)
        ha_diag_warning("parsing [%s:%d] : pattern '%s' looks like a failed attempt at commenting an end of line\n", file, line, arg);
      else if (find_acl_kw(arg))
        ha_diag_warning("parsing [%s:%d] : pattern '%s' suspiciously looks like a known acl keyword\n", file, line, arg);
      else {
        const char *begw = arg, *endw;

        for (endw = begw; is_idchar(*endw); endw++)
          ;

        if (endw != begw && find_sample_fetch(begw, endw - begw))
          ha_diag_warning("parsing [%s:%d] : pattern '%s' suspiciously looks like a known sample fetch keyword\n", file, line, arg);
      }
    }
    args++;
  }

  return expr;

 out_free_expr:
  prune_acl_expr(expr);
  free(expr);
 out_free_smp:
  free(ckw);
  free(smp);
 out_return:
  return NULL;
}

/* Purge everything in the acl <acl>, then return <acl>. */
struct acl *prune_acl(struct acl *acl) {

  struct acl_expr *expr, *exprb;

  free(acl->name);

  list_for_each_entry_safe(expr, exprb, &acl->expr, list) {
    LIST_DELETE(&expr->list);
    prune_acl_expr(expr);
    free(expr);
  }

  return acl;
}

/* Walk the ACL tree, following nested acl() sample fetches, for no more than
 * max_recurse evaluations. Returns -1 if a recursive loop is detected, 0 if
 * the max_recurse was reached, otherwise the number of max_recurse left.
 */
static int parse_acl_recurse(struct acl *acl, struct acl_expr *expr, int max_recurse)
{
  struct acl_term *term;
  struct acl_sample *sample;

  if (strcmp(expr->smp->fetch->kw, "acl") != 0)
    return max_recurse;

  if (--max_recurse <= 0)
    return 0;

  sample = (struct acl_sample *)expr->smp->arg_p->data.ptr;
  list_for_each_entry(term, &sample->suite.terms, list) {
    if (term->acl == acl)
      return -1;
    list_for_each_entry(expr, &term->acl->expr, list) {
      max_recurse = parse_acl_recurse(acl, expr, max_recurse);
      if (max_recurse <= 0)
        return max_recurse;
    }
  }

  return max_recurse;
}

/* Parse an ACL with the name starting at <args>[0], and with a list of already
 * known ACLs in <acl>. If the ACL was not in the list, it will be added.
 * A pointer to that ACL is returned. If the ACL has an empty name, then it's
 * an anonymous one and it won't be merged with any other one. If <err> is not
 * NULL, it will be filled with an appropriate error. This pointer must be
 * freeable or NULL. <al> is the arg_list serving as a head for unresolved
 * dependencies. It may be NULL if such dependencies are not allowed.
 *
 * args syntax: <aclname> <acl_expr>
 */
struct acl *parse_acl(const char **args, struct list *known_acl, char **err, struct arg_list *al,
                      const char *file, int line)
{
  __label__ out_return, out_free_acl_expr, out_free_name;
  struct acl *cur_acl;
  struct acl_expr *acl_expr;
  char *name;
  const char *pos;

  if (**args && (pos = invalid_char(*args))) {
    memprintf(err, "invalid character in ACL name : '%c'", *pos);
    goto out_return;
  }

  acl_expr = parse_acl_expr(args + 1, err, al, file, line);
  if (!acl_expr) {
    /* parse_acl_expr will have filled <err> here */
    goto out_return;
  }

  /* Check for args beginning with an opening parenthesis just after the
   * subject, as this is almost certainly a typo. Right now we can only
   * emit a warning, so let's do so.
   */
  if (!strchr(args[1], '(') && *args[2] == '(')
    ha_warning("parsing acl '%s' :\n"
         "  matching '%s' for pattern '%s' is likely a mistake and probably\n"
         "  not what you want. Maybe you need to remove the extraneous space before '('.\n"
         "  If you are really sure this is not an error, please insert '--' between the\n"
         "  match and the pattern to make this warning message disappear.\n",
         args[0], args[1], args[2]);

  if (*args[0])
    cur_acl = find_acl_by_name(args[0], known_acl);
  else
    cur_acl = NULL;

  if (cur_acl) {
    int ret = parse_acl_recurse(cur_acl, acl_expr, ACL_MAX_RECURSE);
    if (ret <= 0) {
      if (ret < 0)
        memprintf(err, "have a recursive loop");
      else
        memprintf(err, "too deep acl() tree");
      goto out_free_acl_expr;
    }
  } else {
    name = strdup(args[0]);
    if (!name) {
      memprintf(err, "out of memory when parsing ACL");
      goto out_free_acl_expr;
    }
    cur_acl = calloc(1, sizeof(*cur_acl));
    if (cur_acl == NULL) {
      memprintf(err, "out of memory when parsing ACL");
      goto out_free_name;
    }

    LIST_INIT(&cur_acl->expr);
    LIST_APPEND(known_acl, &cur_acl->list);
    cur_acl->name = name;
  }

  /* We want to know what features the ACL needs (typically HTTP parsing),
   * and where it may be used. If an ACL relies on multiple matches, it is
   * OK if at least one of them may match in the context where it is used.
   */
  cur_acl->use |= acl_expr->smp->fetch->use;
  cur_acl->val |= acl_expr->smp->fetch->val;
  LIST_APPEND(&cur_acl->expr, &acl_expr->list);
  return cur_acl;

 out_free_name:
  free(name);
 out_free_acl_expr:
  prune_acl_expr(acl_expr);
  free(acl_expr);
 out_return:
  return NULL;
}

/* Some useful ACLs provided by default. Only those used are allocated. */

const struct {
  const char *name;
  const char *expr[4]; /* put enough for longest expression */
} default_acl_list[] = {
  { .name = "TRUE",           .expr = {"always_true",""}},
  { .name = "FALSE",          .expr = {"always_false",""}},
  { .name = "LOCALHOST",      .expr = {"src","127.0.0.1/8","::1",""}},
  { .name = "HTTP",           .expr = {"req.proto_http",""}},
  { .name = "HTTP_1.0",       .expr = {"req.ver","1.0",""}},
  { .name = "HTTP_1.1",       .expr = {"req.ver","1.1",""}},
  { .name = "HTTP_2.0",       .expr = {"req.ver","2.0",""}},
  { .name = "HTTP_3.0",       .expr = {"req.ver","3.0",""}},
  { .name = "METH_CONNECT",   .expr = {"method","CONNECT",""}},
  { .name = "METH_DELETE",    .expr = {"method","DELETE",""}},
  { .name = "METH_GET",       .expr = {"method","GET","HEAD",""}},
  { .name = "METH_HEAD",      .expr = {"method","HEAD",""}},
  { .name = "METH_OPTIONS",   .expr = {"method","OPTIONS",""}},
  { .name = "METH_POST",      .expr = {"method","POST",""}},
  { .name = "METH_PUT",       .expr = {"method","PUT",""}},
  { .name = "METH_TRACE",     .expr = {"method","TRACE",""}},
  { .name = "HTTP_URL_ABS",   .expr = {"url_reg","^[^/:]*://",""}},
  { .name = "HTTP_URL_SLASH", .expr = {"url_beg","/",""}},
  { .name = "HTTP_URL_STAR",  .expr = {"url","*",""}},
  { .name = "HTTP_CONTENT",   .expr = {"req.hdr_val(content-length)","gt","0",""}},
  { .name = "RDP_COOKIE",     .expr = {"req.rdp_cookie_cnt","gt","0",""}},
  { .name = "REQ_CONTENT",    .expr = {"req.len","gt","0",""}},
  { .name = "WAIT_END",       .expr = {"wait_end",""}},
  { .name = NULL, .expr = {""}}
};

/* Find a default ACL from the default_acl list, compile it and return it.
 * If the ACL is not found, NULL is returned. In theory, it cannot fail,
 * except when default ACLs are broken, in which case it will return NULL.
 * If <known_acl> is not NULL, the ACL will be queued at its tail. If <err> is
 * not NULL, it will be filled with an error message if an error occurs. This
 * pointer must be freeable or NULL. <al> is an arg_list serving as a list head
 * to report missing dependencies. It may be NULL if such dependencies are not
 * allowed.
 */
struct acl *find_acl_default(const char *acl_name, struct list *known_acl,
                             char **err, struct arg_list *al,
                             const char *file, int line)
{
  __label__ out_return, out_free_acl_expr, out_free_name;
  struct acl *cur_acl;
  struct acl_expr *acl_expr;
  char *name;
  int index;

  for (index = 0; default_acl_list[index].name != NULL; index++) {
    if (strcmp(acl_name, default_acl_list[index].name) == 0)
      break;
  }

  if (default_acl_list[index].name == NULL) {
    memprintf(err, "no such ACL : '%s'", acl_name);
    return NULL;
  }

  acl_expr = parse_acl_expr((const char **)default_acl_list[index].expr, err, al, file, line);
  if (!acl_expr) {
    /* parse_acl_expr must have filled err here */
    goto out_return;
  }

  name = strdup(acl_name);
  if (!name) {
    memprintf(err, "out of memory when building default ACL '%s'", acl_name);
    goto out_free_acl_expr;
  }

  cur_acl = calloc(1, sizeof(*cur_acl));
  if (cur_acl == NULL) {
    memprintf(err, "out of memory when building default ACL '%s'", acl_name);
    goto out_free_name;
  }

  cur_acl->name = name;
  cur_acl->use |= acl_expr->smp->fetch->use;
  cur_acl->val |= acl_expr->smp->fetch->val;
  LIST_INIT(&cur_acl->expr);
  LIST_APPEND(&cur_acl->expr, &acl_expr->list);
  if (known_acl)
    LIST_APPEND(known_acl, &cur_acl->list);

  return cur_acl;

 out_free_name:
  free(name);
 out_free_acl_expr:
  prune_acl_expr(acl_expr);
  free(acl_expr);
 out_return:
  return NULL;
}

/* Parse an ACL condition starting at <args>[0], relying on a list of already
 * known ACLs passed in <known_acl>. The new condition is returned (or NULL in
 * case of low memory). Supports multiple conditions separated by "or". If
 * <err> is not NULL, it will be filled with a pointer to an error message in
 * case of error, that the caller is responsible for freeing. The initial
 * location must either be freeable or NULL. The list <al> serves as a list head
 * for unresolved dependencies. It may be NULL if such dependencies are not
 * allowed.
 */
struct acl_cond *parse_acl_cond(const char **args, struct list *known_acl,
                                enum acl_cond_pol pol, char **err, struct arg_list *al,
                                const char *file, int line)
{
  __label__ out_return, out_free_suite, out_free_term;
  int arg, neg;
  const char *word;
  struct acl *cur_acl;
  struct acl_term *cur_term;
  struct acl_term_suite *cur_suite;
  struct acl_cond *cond;
  unsigned int suite_val;

  cond = calloc(1, sizeof(*cond));
  if (cond == NULL) {
    memprintf(err, "out of memory when parsing condition");
    goto out_return;
  }

  LIST_INIT(&cond->list);
  LIST_INIT(&cond->suites);
  cond->pol = pol;
  cond->val = 0;

  cur_suite = NULL;
  suite_val = ~0U;
  neg = 0;
  for (arg = 0; *args[arg]; arg++) {
    word = args[arg];

    /* remove as many exclamation marks as we can */
    while (*word == '!') {
      neg = !neg;
      word++;
    }

    /* an empty word is allowed because we cannot force the user to
     * always think about not leaving exclamation marks alone.
     */
    if (!*word)
      continue;

    if (strcasecmp(word, "or") == 0 || strcmp(word, "||") == 0) {
      /* new term suite */
      cond->val |= suite_val;
      suite_val = ~0U;
      cur_suite = NULL;
      neg = 0;
      continue;
    }

    if (strcmp(word, "{") == 0) {
      /* we may have a complete ACL expression between two braces,
       * find the last one.
       */
      int arg_end = arg + 1;
      const char **args_new;

      while (*args[arg_end] && strcmp(args[arg_end], "}") != 0)
        arg_end++;

      if (!*args[arg_end]) {
        memprintf(err, "missing closing '}' in condition");
        goto out_free_suite;
      }

      args_new = calloc(1, (arg_end - arg + 1) * sizeof(*args_new));
      if (!args_new) {
        memprintf(err, "out of memory when parsing condition");
        goto out_free_suite;
      }

      args_new[0] = "";
      memcpy(args_new + 1, args + arg + 1, (arg_end - arg) * sizeof(*args_new));
      args_new[arg_end - arg] = "";
      cur_acl = parse_acl(args_new, known_acl, err, al, file, line);
      free(args_new);

      if (!cur_acl) {
        /* note that parse_acl() must have filled <err> here */
        goto out_free_suite;
      }
      arg = arg_end;
    }
    else {
      /* search for <word> in the known ACL names. If we do not find
       * it, let's look for it in the default ACLs, and if found, add
       * it to the list of ACLs of this proxy. This makes it possible
       * to override them.
       */
      cur_acl = find_acl_by_name(word, known_acl);
      if (cur_acl == NULL) {
        cur_acl = find_acl_default(word, known_acl, err, al, file, line);
        if (cur_acl == NULL) {
          /* note that find_acl_default() must have filled <err> here */
          goto out_free_suite;
        }
      }
    }

    cur_term = calloc(1, sizeof(*cur_term));
    if (cur_term == NULL) {
      memprintf(err, "out of memory when parsing condition");
      goto out_free_suite;
    }

    cur_term->acl = cur_acl;
    cur_term->neg = neg;

    /* Here it is a bit complex. The acl_term_suite is a conjunction
     * of many terms. It may only be used if all of its terms are
     * usable at the same time. So the suite's validity domain is an
     * AND between all ACL keywords' ones. But, the global condition
     * is valid if at least one term suite is OK. So it's an OR between
     * all of their validity domains. We could emit a warning as soon
     * as suite_val is null because it means that the last ACL is not
     * compatible with the previous ones. Let's remain simple for now.
     */
    cond->use |= cur_acl->use;
    suite_val &= cur_acl->val;

    if (!cur_suite) {
      cur_suite = calloc(1, sizeof(*cur_suite));
      if (cur_suite == NULL) {
        memprintf(err, "out of memory when parsing condition");
        goto out_free_term;
      }
      LIST_INIT(&cur_suite->terms);
      LIST_APPEND(&cond->suites, &cur_suite->list);
    }
    LIST_APPEND(&cur_suite->terms, &cur_term->list);
    neg = 0;
  }

  cond->val |= suite_val;
  return cond;

 out_free_term:
  free(cur_term);
 out_free_suite:
  free_acl_cond(cond);
 out_return:
  return NULL;
}

/* Builds an ACL condition starting at the if/unless keyword. The complete
 * condition is returned. NULL is returned in case of error or if the first
 * word is neither "if" nor "unless". It automatically sets the file name and
 * the line number in the condition for better error reporting, and sets the
 * HTTP initialization requirements in the proxy. If <err> is not NULL, it will
 * be filled with a pointer to an error message in case of error, that the
 * caller is responsible for freeing. The initial location must either be
 * freeable or NULL.
 */
struct acl_cond *build_acl_cond(const char *file, int line, struct list *known_acl,
        struct proxy *px, const char **args, char **err)
{
  enum acl_cond_pol pol = ACL_COND_NONE;
  struct acl_cond *cond = NULL;

  if (err)
    *err = NULL;

  if (strcmp(*args, "if") == 0) {
    pol = ACL_COND_IF;
    args++;
  }
  else if (strcmp(*args, "unless") == 0) {
    pol = ACL_COND_UNLESS;
    args++;
  }
  else {
    memprintf(err, "conditions must start with either 'if' or 'unless'");
    return NULL;
  }

  cond = parse_acl_cond(args, known_acl, pol, err, &px->conf.args, file, line);
  if (!cond) {
    /* note that parse_acl_cond must have filled <err> here */
    return NULL;
  }

  cond->file = file;
  cond->line = line;
  px->http_needed |= !!(cond->use & SMP_USE_HTTP_ANY);
  return cond;
}

/* Execute condition <cond> and return either ACL_TEST_FAIL, ACL_TEST_MISS or
 * ACL_TEST_PASS depending on the test results. ACL_TEST_MISS may only be
 * returned if <opt> does not contain SMP_OPT_FINAL, indicating that incomplete
 * data is being examined. The function automatically sets SMP_OPT_ITERATE. This
 * function only computes the condition, it does not apply the polarity required
 * by IF/UNLESS, it's up to the caller to do this using something like this :
 *
 *     res = acl_pass(res);
 *     if (res == ACL_TEST_MISS)
 *         return 0;
 *     if (cond->pol == ACL_COND_UNLESS)
 *         res = !res;
 */
enum acl_test_res acl_exec_cond(struct acl_cond *cond, struct proxy *px, struct session *sess, struct stream *strm, unsigned int opt)
{
  __label__ fetch_next;
  struct acl_term_suite *suite;
  struct acl_term *term;
  struct acl_expr *expr;
  struct acl *acl;
  struct sample smp;
  enum acl_test_res acl_res, suite_res, cond_res;

  /* ACLs are iterated over all values, so let's always set the flag to
   * indicate this to the fetch functions.
   */
  opt |= SMP_OPT_ITERATE;

  /* We're doing a logical OR between conditions so we initialize to FAIL.
   * The MISS status is propagated down from the suites.
   */
  cond_res = ACL_TEST_FAIL;
  list_for_each_entry(suite, &cond->suites, list) {
    /* Evaluate condition suite <suite>. We stop at the first term
     * which returns ACL_TEST_FAIL. The MISS status is still propagated
     * in case of uncertainty in the result.
     */

    /* we're doing a logical AND between terms, so we must set the
     * initial value to PASS.
     */
    suite_res = ACL_TEST_PASS;
    list_for_each_entry(term, &suite->terms, list) {
      acl = term->acl;

      /* FIXME: use cache !
       * check acl->cache_idx for this.
       */

      /* ACL result not cached. Let's scan all the expressions
       * and use the first one to match.
       */
      acl_res = ACL_TEST_FAIL;
      list_for_each_entry(expr, &acl->expr, list) {
        /* we need to reset context and flags */
        memset(&smp, 0, sizeof(smp));
      fetch_next:
        if (!sample_process(px, sess, strm, opt, expr->smp, &smp)) {
          /* maybe we could not fetch because of missing data */
          if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
            acl_res |= ACL_TEST_MISS;
          continue;
        }

        acl_res |= pat2acl(pattern_exec_match(&expr->pat, &smp, 0));
        /*
         * OK now acl_res holds the result of this expression
         * as one of ACL_TEST_FAIL, ACL_TEST_MISS or ACL_TEST_PASS.
         *
         * Then if (!MISS) we can cache the result, and put
         * (smp.flags & SMP_F_VOLATILE) in the cache flags.
         *
         * FIXME: implement cache.
         *
         */

        /* we're ORing these terms, so a single PASS is enough */
        if (acl_res == ACL_TEST_PASS)
          break;

        if (smp.flags & SMP_F_NOT_LAST)
          goto fetch_next;

        /* sometimes we know the fetched data is subject to change
         * later and give another chance for a new match (eg: request
         * size, time, ...)
         */
        if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
          acl_res |= ACL_TEST_MISS;
      }
      /*
       * Here we have the result of an ACL (cached or not).
       * ACLs are combined, negated or not, to form conditions.
       */

      if (term->neg)
        acl_res = acl_neg(acl_res);

      suite_res &= acl_res;

      /* we're ANDing these terms, so a single FAIL or MISS is enough */
      if (suite_res != ACL_TEST_PASS)
        break;
    }
    cond_res |= suite_res;

    /* we're ORing these terms, so a single PASS is enough */
    if (cond_res == ACL_TEST_PASS)
      break;
  }
  return cond_res;
}

/* Returns a pointer to the first ACL conflicting with usage at place <where>
 * which is one of the SMP_VAL_* bits indicating a check place, or NULL if
 * no conflict is found. Only full conflicts are detected (ACL is not usable).
 * Use the next function to check for useless keywords.
 */
const struct acl *acl_cond_conflicts(const struct acl_cond *cond, unsigned int where)
{
  struct acl_term_suite *suite;
  struct acl_term *term;
  struct acl *acl;

  list_for_each_entry(suite, &cond->suites, list) {
    list_for_each_entry(term, &suite->terms, list) {
      acl = term->acl;
      if (!(acl->val & where))
        return acl;
    }
  }
  return NULL;
}

/* Returns a pointer to the first ACL and its first keyword to conflict with
 * usage at place <where> which is one of the SMP_VAL_* bits indicating a check
 * place. Returns true if a conflict is found, with <acl> and <kw> set (if non
 * null), or false if not conflict is found. The first useless keyword is
 * returned.
 */
int acl_cond_kw_conflicts(const struct acl_cond *cond, unsigned int where, struct acl const **acl, char const **kw)
{
  struct acl_term_suite *suite;
  struct acl_term *term;
  struct acl_expr *expr;

  list_for_each_entry(suite, &cond->suites, list) {
    list_for_each_entry(term, &suite->terms, list) {
      list_for_each_entry(expr, &term->acl->expr, list) {
        if (!(expr->smp->fetch->val & where)) {
          if (acl)
            *acl = term->acl;
          if (kw)
            *kw = expr->kw;
          return 1;
        }
      }
    }
  }
  return 0;
}

/*
 * Find targets for userlist and groups in acl. Function returns the number
 * of errors or OK if everything is fine. It must be called only once sample
 * fetch arguments have been resolved (after smp_resolve_args()).
 */
int acl_find_targets(struct proxy *p)
{

  struct acl *acl;
  struct acl_expr *expr;
  struct pattern_list *pattern;
  int cfgerr = 0;
  struct pattern_expr_list *pexp;

  list_for_each_entry(acl, &p->acl, list) {
    list_for_each_entry(expr, &acl->expr, list) {
      if (strcmp(expr->kw, "http_auth_group") == 0) {
        /* Note: the ARGT_USR argument may only have been resolved earlier
         * by smp_resolve_args().
         */
        if (expr->smp->arg_p->unresolved) {
          ha_alert("Internal bug in proxy %s: %sacl %s %s() makes use of unresolved userlist '%s'. Please report this.\n",
             p->id, *acl->name ? "" : "anonymous ", acl->name, expr->kw,
             expr->smp->arg_p->data.str.area);
          cfgerr++;
          continue;
        }

        if (LIST_ISEMPTY(&expr->pat.head)) {
          ha_alert("proxy %s: acl %s %s(): no groups specified.\n",
             p->id, acl->name, expr->kw);
          cfgerr++;
          continue;
        }

        /* For each pattern, check if the group exists. */
        list_for_each_entry(pexp, &expr->pat.head, list) {
          if (LIST_ISEMPTY(&pexp->expr->patterns)) {
            ha_alert("proxy %s: acl %s %s(): no groups specified.\n",
               p->id, acl->name, expr->kw);
            cfgerr++;
            continue;
          }

          list_for_each_entry(pattern, &pexp->expr->patterns, list) {
            /* this keyword only has one argument */
            if (!check_group(expr->smp->arg_p->data.usr, pattern->pat.ptr.str)) {
              ha_alert("proxy %s: acl %s %s(): invalid group '%s'.\n",
                 p->id, acl->name, expr->kw, pattern->pat.ptr.str);
              cfgerr++;
            }
          }
        }
      }
    }
  }

  return cfgerr;
}

/* initializes ACLs by resolving the sample fetch names they rely upon.
 * Returns 0 on success, otherwise an error.
 */
int init_acl()
{
  int err = 0;
  int index;
  const char *name;
  struct acl_kw_list *kwl;
  struct sample_fetch *smp;

  list_for_each_entry(kwl, &acl_keywords.list, list) {
    for (index = 0; kwl->kw[index].kw != NULL; index++) {
      name = kwl->kw[index].fetch_kw;
      if (!name)
        name = kwl->kw[index].kw;

      smp = find_sample_fetch(name, strlen(name));
      if (!smp) {
        ha_alert("Critical internal error: ACL keyword '%s' relies on sample fetch '%s' which was not registered!\n",
           kwl->kw[index].kw, name);
        err++;
        continue;
      }
      kwl->kw[index].smp = smp;
    }
  }
  return err;
}

/* dump known ACL keywords on stdout */
void acl_dump_kwd(void)
{
  struct acl_kw_list *kwl;
  const struct acl_keyword *kwp, *kw;
  const char *name;
  int index;

  for (kw = kwp = NULL;; kwp = kw) {
    list_for_each_entry(kwl, &acl_keywords.list, list) {
      for (index = 0; kwl->kw[index].kw != NULL; index++) {
        if (strordered(kwp ? kwp->kw : NULL,
                 kwl->kw[index].kw,
                 kw != kwp ? kw->kw : NULL))
          kw = &kwl->kw[index];
      }
    }

    if (kw == kwp)
      break;

    name = kw->fetch_kw;
    if (!name)
      name = kw->kw;

    printf("%s = %s -m %s\n", kw->kw, name, pat_match_names[kw->match_type]);
  }
}

/* Purge everything in the acl_cond <cond>, then free <cond> */
void free_acl_cond(struct acl_cond *cond)
{
  struct acl_term_suite *suite, *suiteb;
  struct acl_term *term, *termb;

  if (!cond)
    return;

  list_for_each_entry_safe(suite, suiteb, &cond->suites, list) {
    list_for_each_entry_safe(term, termb, &suite->terms, list) {
      LIST_DELETE(&term->list);
      free(term);
    }
    LIST_DELETE(&suite->list);
    free(suite);
  }

  free(cond);
}


static int smp_fetch_acl(const struct arg *args, struct sample *smp, const char *kw, void *private)
{
  struct acl_sample *acl_sample = (struct acl_sample *)args->data.ptr;
  enum acl_test_res ret;

  ret = acl_exec_cond(&acl_sample->cond, smp->px, smp->sess, smp->strm, smp->opt);
  if (ret == ACL_TEST_MISS)
    return 0;
  smp->data.u.sint = ret == ACL_TEST_PASS;
  smp->data.type = SMP_T_BOOL;
  return 1;
}

int smp_fetch_acl_parse(struct arg *args, char **err_msg)
{
  struct acl_sample *acl_sample;
  char *name;
  int i;

  for (i = 0; args[i].type != ARGT_STOP; i++)
    ;
  acl_sample = calloc(1, sizeof(struct acl_sample) + sizeof(struct acl_term) * i);
  if (unlikely(!acl_sample)) {
    memprintf(err_msg, "out of memory when parsing ACL expression");
    return 0;
  }
  LIST_INIT(&acl_sample->suite.terms);
  LIST_INIT(&acl_sample->cond.suites);
  LIST_APPEND(&acl_sample->cond.suites, &acl_sample->suite.list);
  acl_sample->cond.val = ~0U; // the keyword is valid everywhere for now.

  args->data.ptr = acl_sample;

  for (i = 0; args[i].type != ARGT_STOP; i++) {
    name = args[i].data.str.area;
    if (name[0] == '!') {
      acl_sample->terms[i].neg = 1;
      name++;
    }


    if (
      !(acl_sample->terms[i].acl = find_acl_by_name(name, &curproxy->acl)) &&
      !(acl_sample->terms[i].acl = find_acl_default(name, &curproxy->acl, err_msg, NULL, NULL, 0))
      ) {
      memprintf(err_msg, "ACL '%s' not found", name);
      goto err;
    }

    acl_sample->cond.use |= acl_sample->terms[i].acl->use;
    acl_sample->cond.val &= acl_sample->terms[i].acl->val;

    LIST_APPEND(&acl_sample->suite.terms, &acl_sample->terms[i].list);
  }

  return 1;

err:
  free(acl_sample);
  return 0;
}

/************************************************************************/
/*      All supported sample and ACL keywords must be declared here.    */
/************************************************************************/

/* Note: must not be declared <const> as its list will be overwritten.
 * Please take care of keeping this list alphabetically sorted.
 */
static struct acl_kw_list acl_kws = {ILH, {
  { /* END */ },
}};

INITCALL1(STG_REGISTER, acl_register_keywords, &acl_kws);

static struct sample_fetch_kw_list smp_kws = {ILH, {
  { "acl", smp_fetch_acl, ARG12(1,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR), smp_fetch_acl_parse, SMP_T_BOOL, SMP_USE_CONST },
  { /* END */ },
}};

INITCALL1(STG_REGISTER, sample_register_fetches, &smp_kws);

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */

Coverage Report

Created: 2026-04-03 06:23