/* execute.c Support for executable statements. */ /* * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1998-2003 by Internet Software Consortium * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Internet Systems Consortium, Inc. * 950 Charter Street * Redwood City, CA 94063 * * http://www.isc.org/ * * This software has been written for Internet Systems Consortium * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc. * To learn more about Internet Systems Consortium, see * ``http://www.isc.org/''. To learn more about Vixie Enterprises, * see ``http://www.vix.com''. To learn more about Nominum, Inc., see * ``http://www.nominum.com''. */ #ifndef lint static char copyright[] = "$Id: execute.c,v 1.44.2.12 2004/11/24 17:39:15 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium. All rights reserved.\n"; #endif /* not lint */ #include "dhcpd.h" #include int execute_statements (result, packet, lease, client_state, in_options, out_options, scope, statements) struct binding_value **result; struct packet *packet; struct lease *lease; struct client_state *client_state; struct option_state *in_options; struct option_state *out_options; struct binding_scope **scope; struct executable_statement *statements; { struct executable_statement *r, *e, *next; int rc; int status; unsigned long num; struct binding_scope *outer; struct binding *binding; struct data_string ds; struct binding_scope *ns; if (!statements) return 1; r = (struct executable_statement *)0; next = (struct executable_statement *)0; e = (struct executable_statement *)0; executable_statement_reference (&r, statements, MDL); while (r && !(result && *result)) { if (r -> next) executable_statement_reference (&next, r -> next, MDL); switch (r -> op) { case statements_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: statements"); #endif status = execute_statements (result, packet, lease, client_state, in_options, out_options, scope, r -> data.statements); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: statements returns %d", status); #endif if (!status) return 0; break; case on_statement: if (lease) { if (r -> data.on.evtypes & ON_EXPIRY) { #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: on expiry"); #endif if (lease -> on_expiry) executable_statement_dereference (&lease -> on_expiry, MDL); if (r -> data.on.statements) executable_statement_reference (&lease -> on_expiry, r -> data.on.statements, MDL); } if (r -> data.on.evtypes & ON_RELEASE) { #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: on release"); #endif if (lease -> on_release) executable_statement_dereference (&lease -> on_release, MDL); if (r -> data.on.statements) executable_statement_reference (&lease -> on_release, r -> data.on.statements, MDL); } if (r -> data.on.evtypes & ON_COMMIT) { #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: on commit"); #endif if (lease -> on_commit) executable_statement_dereference (&lease -> on_commit, MDL); if (r -> data.on.statements) executable_statement_reference (&lease -> on_commit, r -> data.on.statements, MDL); } } break; case switch_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: switch"); #endif status = (find_matching_case (&e, packet, lease, client_state, in_options, out_options, scope, r -> data.s_switch.expr, r -> data.s_switch.statements)); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: switch: case %lx", (unsigned long)e); #endif if (status) { if (!(execute_statements (result, packet, lease, client_state, in_options, out_options, scope, e))) { executable_statement_dereference (&e, MDL); return 0; } executable_statement_dereference (&e, MDL); } break; /* These have no effect when executed. */ case case_statement: case default_statement: break; case if_statement: status = (evaluate_boolean_expression (&rc, packet, lease, client_state, in_options, out_options, scope, r -> data.ie.expr)); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: if %s", (status ? (rc ? "true" : "false") : "NULL")); #endif /* XXX Treat NULL as false */ if (!status) rc = 0; if (!execute_statements (result, packet, lease, client_state, in_options, out_options, scope, rc ? r -> data.ie.tc : r -> data.ie.fc)) return 0; break; case eval_statement: status = evaluate_expression ((struct binding_value **)0, packet, lease, client_state, in_options, out_options, scope, r -> data.eval, MDL); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: evaluate: %s", (status ? "succeeded" : "failed")); #endif break; case return_statement: status = evaluate_expression (result, packet, lease, client_state, in_options, out_options, scope, r -> data.retval, MDL); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: return: %s", (status ? "succeeded" : "failed")); #endif break; case add_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: add %s", (r -> data.add -> name ? r -> data.add -> name : "")); #endif classify (packet, r -> data.add); break; case break_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: break"); #endif return 1; case supersede_option_statement: case send_option_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: %s option %s.%s", (r -> op == supersede_option_statement ? "supersede" : "send"), r -> data.option -> option -> universe -> name, r -> data.option -> option -> name); goto option_statement; #endif case default_option_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: default option %s.%s", r -> data.option -> option -> universe -> name, r -> data.option -> option -> name); goto option_statement; #endif case append_option_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: append option %s.%s", r -> data.option -> option -> universe -> name, r -> data.option -> option -> name); goto option_statement; #endif case prepend_option_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: prepend option %s.%s", r -> data.option -> option -> universe -> name, r -> data.option -> option -> name); option_statement: #endif set_option (r -> data.option -> option -> universe, out_options, r -> data.option, r -> op); break; case set_statement: case define_statement: if (!scope) { log_error ("set %s: no scope", r -> data.set.name); status = 0; break; } if (!*scope) { if (!binding_scope_allocate (scope, MDL)) { log_error ("set %s: can't allocate scope", r -> data.set.name); status = 0; break; } } binding = find_binding (*scope, r -> data.set.name); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: set %s", r -> data.set.name); #endif if (!binding) { binding = dmalloc (sizeof *binding, MDL); if (binding) { memset (binding, 0, sizeof *binding); binding -> name = dmalloc (strlen (r -> data.set.name) + 1, MDL); if (binding -> name) { strcpy (binding -> name, r -> data.set.name); binding -> next = (*scope) -> bindings; (*scope) -> bindings = binding; } else { badalloc: dfree (binding, MDL); binding = (struct binding *)0; } } } if (binding) { if (binding -> value) binding_value_dereference (&binding -> value, MDL); if (r -> op == set_statement) { status = (evaluate_expression (&binding -> value, packet, lease, client_state, in_options, out_options, scope, r -> data.set.expr, MDL)); } else { if (!(binding_value_allocate (&binding -> value, MDL))) { dfree (binding, MDL); binding = (struct binding *)0; } if (binding -> value) { binding -> value -> type = binding_function; (fundef_reference (&binding -> value -> value.fundef, r -> data.set.expr -> data.func, MDL)); } } } #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: set %s%s", r -> data.set.name, (binding && status ? "" : " (failed)")); #endif break; case unset_statement: if (!scope || !*scope) { status = 0; break; } binding = find_binding (*scope, r -> data.unset); if (binding) { if (binding -> value) binding_value_dereference (&binding -> value, MDL); status = 1; } else status = 0; #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: unset %s: %s", r -> data.unset, (status ? "found" : "not found")); #endif break; case let_statement: #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: let %s", r -> data.let.name); #endif ns = (struct binding_scope *)0; binding_scope_allocate (&ns, MDL); e = r; next_let: if (ns) { binding = dmalloc (sizeof *binding, MDL); memset (binding, 0, sizeof *binding); if (!binding) { blb: binding_scope_dereference (&ns, MDL); } else { binding -> name = dmalloc (strlen (e -> data.let.name + 1), MDL); if (binding -> name) strcpy (binding -> name, e -> data.let.name); else { dfree (binding, MDL); binding = (struct binding *)0; goto blb; } } } else binding = NULL; if (ns && binding) { status = (evaluate_expression (&binding -> value, packet, lease, client_state, in_options, out_options, scope, e -> data.set.expr, MDL)); binding -> next = ns -> bindings; ns -> bindings = binding; } #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: let %s%s", e -> data.let.name, (binding && status ? "" : "failed")); #endif if (!e -> data.let.statements) { } else if (e -> data.let.statements -> op == let_statement) { e = e -> data.let.statements; goto next_let; } else if (ns) { if (scope && *scope) binding_scope_reference (&ns -> outer, *scope, MDL); execute_statements (result, packet, lease, client_state, in_options, out_options, &ns, e -> data.let.statements); } if (ns) binding_scope_dereference (&ns, MDL); break; case log_statement: memset (&ds, 0, sizeof ds); status = (evaluate_data_expression (&ds, packet, lease, client_state, in_options, out_options, scope, r -> data.log.expr, MDL)); #if defined (DEBUG_EXPRESSIONS) log_debug ("exec: log"); #endif if (status) { switch (r -> data.log.priority) { case log_priority_fatal: log_fatal ("%.*s", (int)ds.len, ds.data); break; case log_priority_error: log_error ("%.*s", (int)ds.len, ds.data); break; case log_priority_debug: log_debug ("%.*s", (int)ds.len, ds.data); break; case log_priority_info: log_info ("%.*s", (int)ds.len, ds.data); break; } data_string_forget (&ds, MDL); } break; default: log_error ("bogus statement type %d", r -> op); break; } executable_statement_dereference (&r, MDL); if (next) { executable_statement_reference (&r, next, MDL); executable_statement_dereference (&next, MDL); } } return 1; } /* Execute all the statements in a particular scope, and all statements in scopes outer from that scope, but if a particular limiting scope is reached, do not execute statements in that scope or in scopes outer from it. More specific scopes need to take precedence over less specific scopes, so we recursively traverse the scope list, executing the most outer scope first. */ void execute_statements_in_scope (result, packet, lease, client_state, in_options, out_options, scope, group, limiting_group) struct binding_value **result; struct packet *packet; struct lease *lease; struct client_state *client_state; struct option_state *in_options; struct option_state *out_options; struct binding_scope **scope; struct group *group; struct group *limiting_group; { struct group *limit; /* If we've recursed as far as we can, return. */ if (!group) return; /* As soon as we get to a scope that is outer than the limiting scope, we are done. This is so that if somebody does something like this, it does the expected thing: domain-name "fugue.com"; shared-network FOO { host bar { domain-name "othello.fugue.com"; fixed-address 10.20.30.40; } subnet 10.20.30.0 netmask 255.255.255.0 { domain-name "manhattan.fugue.com"; } } The problem with the above arrangement is that the host's group nesting will be host -> shared-network -> top-level, and the limiting scope when we evaluate the host's scope will be the subnet -> shared-network -> top-level, so we need to know when we evaluate the host's scope to stop before we evaluate the shared-networks scope, because it's outer than the limiting scope, which means we've already evaluated it. */ for (limit = limiting_group; limit; limit = limit -> next) { if (group == limit) return; } if (group -> next) execute_statements_in_scope (result, packet, lease, client_state, in_options, out_options, scope, group -> next, limiting_group); execute_statements (result, packet, lease, client_state, in_options, out_options, scope, group -> statements); } /* Dereference or free any subexpressions of a statement being freed. */ int executable_statement_dereference (ptr, file, line) struct executable_statement **ptr; const char *file; int line; { struct executable_statement *bp; if (!ptr || !*ptr) { log_error ("%s(%d): null pointer", file, line); #if defined (POINTER_DEBUG) abort (); #else return 0; #endif } (*ptr) -> refcnt--; rc_register (file, line, ptr, *ptr, (*ptr) -> refcnt, 1, RC_MISC); if ((*ptr) -> refcnt > 0) { *ptr = (struct executable_statement *)0; return 1; } if ((*ptr) -> refcnt < 0) { log_error ("%s(%d): negative refcnt!", file, line); #if defined (DEBUG_RC_HISTORY) dump_rc_history (*ptr); #endif #if defined (POINTER_DEBUG) abort (); #else return 0; #endif } if ((*ptr) -> next) executable_statement_dereference (&(*ptr) -> next, file, line); switch ((*ptr) -> op) { case statements_statement: if ((*ptr) -> data.statements) executable_statement_dereference (&(*ptr) -> data.statements, file, line); break; case on_statement: if ((*ptr) -> data.on.statements) executable_statement_dereference (&(*ptr) -> data.on.statements, file, line); break; case switch_statement: if ((*ptr) -> data.s_switch.statements) executable_statement_dereference (&(*ptr) -> data.on.statements, file, line); if ((*ptr) -> data.s_switch.expr) expression_dereference (&(*ptr) -> data.s_switch.expr, file, line); break; case case_statement: if ((*ptr) -> data.s_switch.expr) expression_dereference (&(*ptr) -> data.c_case, file, line); break; case if_statement: if ((*ptr) -> data.ie.expr) expression_dereference (&(*ptr) -> data.ie.expr, file, line); if ((*ptr) -> data.ie.tc) executable_statement_dereference (&(*ptr) -> data.ie.tc, file, line); if ((*ptr) -> data.ie.fc) executable_statement_dereference (&(*ptr) -> data.ie.fc, file, line); break; case eval_statement: if ((*ptr) -> data.eval) expression_dereference (&(*ptr) -> data.eval, file, line); break; case return_statement: if ((*ptr) -> data.eval) expression_dereference (&(*ptr) -> data.eval, file, line); break; case set_statement: if ((*ptr)->data.set.name) dfree ((*ptr)->data.set.name, file, line); if ((*ptr)->data.set.expr) expression_dereference (&(*ptr) -> data.set.expr, file, line); break; case unset_statement: if ((*ptr)->data.unset) dfree ((*ptr)->data.unset, file, line); break; case supersede_option_statement: case send_option_statement: case default_option_statement: case append_option_statement: case prepend_option_statement: if ((*ptr) -> data.option) option_cache_dereference (&(*ptr) -> data.option, file, line); break; default: /* Nothing to do. */ break; } dfree ((*ptr), file, line); *ptr = (struct executable_statement *)0; return 1; } void write_statements (file, statements, indent) FILE *file; struct executable_statement *statements; int indent; { struct executable_statement *r, *x; int result; int status; const char *s, *t, *dot; int col; if (!statements) return; for (r = statements; r; r = r -> next) { switch (r -> op) { case statements_statement: write_statements (file, r -> data.statements, indent); break; case on_statement: indent_spaces (file, indent); fprintf (file, "on "); s = ""; if (r -> data.on.evtypes & ON_EXPIRY) { fprintf (file, "%sexpiry", s); s = " or "; } if (r -> data.on.evtypes & ON_COMMIT) { fprintf (file, "%scommit", s); s = "or"; } if (r -> data.on.evtypes & ON_RELEASE) { fprintf (file, "%srelease", s); s = "or"; } if (r -> data.on.statements) { fprintf (file, " {"); write_statements (file, r -> data.on.statements, indent + 2); indent_spaces (file, indent); fprintf (file, "}"); } else { fprintf (file, ";"); } break; case switch_statement: indent_spaces (file, indent); fprintf (file, "switch ("); col = write_expression (file, r -> data.s_switch.expr, indent + 7, indent + 7, 1); col = token_print_indent (file, col, indent + 7, "", "", ")"); token_print_indent (file, col, indent, " ", "", "{"); write_statements (file, r -> data.s_switch.statements, indent + 2); indent_spaces (file, indent); fprintf (file, "}"); break; case case_statement: indent_spaces (file, indent - 1); fprintf (file, "case "); col = write_expression (file, r -> data.s_switch.expr, indent + 5, indent + 5, 1); token_print_indent (file, col, indent + 5, "", "", ":"); break; case default_statement: indent_spaces (file, indent - 1); fprintf (file, "default: "); break; case if_statement: indent_spaces (file, indent); fprintf (file, "if "); x = r; col = write_expression (file, x -> data.ie.expr, indent + 3, indent + 3, 1); else_if: token_print_indent (file, col, indent, " ", "", "{"); write_statements (file, x -> data.ie.tc, indent + 2); if (x -> data.ie.fc && x -> data.ie.fc -> op == if_statement && !x -> data.ie.fc -> next) { indent_spaces (file, indent); fprintf (file, "} elsif "); x = x -> data.ie.fc; col = write_expression (file, x -> data.ie.expr, indent + 6, indent + 6, 1); goto else_if; } if (x -> data.ie.fc) { indent_spaces (file, indent); fprintf (file, "} else {"); write_statements (file, x -> data.ie.fc, indent + 2); } indent_spaces (file, indent); fprintf (file, "}"); break; case eval_statement: indent_spaces (file, indent); fprintf (file, "eval "); col = write_expression (file, r -> data.eval, indent + 5, indent + 5, 1); fprintf (file, ";"); break; case return_statement: indent_spaces (file, indent); fprintf (file, "return;"); break; case add_statement: indent_spaces (file, indent); fprintf (file, "add \"%s\"", r -> data.add -> name); break; case break_statement: indent_spaces (file, indent); fprintf (file, "break;"); break; case supersede_option_statement: case send_option_statement: s = "supersede"; goto option_statement; case default_option_statement: s = "default"; goto option_statement; case append_option_statement: s = "append"; goto option_statement; case prepend_option_statement: s = "prepend"; option_statement: /* Note: the reason we don't try to pretty print the option here is that the format of the option may change in dhcpd.conf, and then when this statement was read back, it would cause a syntax error. */ if (r -> data.option -> option -> universe == &dhcp_universe) { t = ""; dot = ""; } else { t = (r -> data.option -> option -> universe -> name); dot = "."; } indent_spaces (file, indent); fprintf (file, "%s %s%s%s = ", s, t, dot, r -> data.option -> option -> name); col = (indent + strlen (s) + strlen (t) + strlen (dot) + strlen (r -> data.option -> option -> name) + 4); if (r -> data.option -> expression) write_expression (file, r -> data.option -> expression, col, indent + 8, 1); else token_indent_data_string (file, col, indent + 8, "", "", &r -> data.option -> data); fprintf (file, ";"); /* XXX */ break; case set_statement: indent_spaces (file, indent); fprintf (file, "set "); col = token_print_indent (file, indent + 4, indent + 4, "", "", r -> data.set.name); col = token_print_indent (file, col, indent + 4, " ", " ", "="); col = write_expression (file, r -> data.set.expr, indent + 3, indent + 3, 0); col = token_print_indent (file, col, indent + 4, " ", "", ";"); break; case unset_statement: indent_spaces (file, indent); fprintf (file, "unset "); col = token_print_indent (file, indent + 6, indent + 6, "", "", r -> data.set.name); col = token_print_indent (file, col, indent + 6, " ", "", ";"); break; case log_statement: indent_spaces (file, indent); fprintf (file, "log "); col = token_print_indent (file, indent + 4, indent + 4, "", "", "("); switch (r -> data.log.priority) { case log_priority_fatal: col = token_print_indent (file, col, indent + 4, "", " ", "fatal,"); break; case log_priority_error: col = token_print_indent (file, col, indent + 4, "", " ", "error,"); break; case log_priority_debug: col = token_print_indent (file, col, indent + 4, "", " ", "debug,"); break; case log_priority_info: col = token_print_indent (file, col, indent + 4, "", " ", "info,"); break; } col = write_expression (file, r -> data.log.expr, indent + 4, indent + 4, 0); col = token_print_indent (file, col, indent + 4, "", "", ");"); break; default: log_fatal ("bogus statement type %d\n", r -> op); } } } /* Find a case statement in the sequence of executable statements that matches the expression, and if found, return the following statement. If no case statement matches, try to find a default statement and return that (the default statement can precede all the case statements). Otherwise, return the null statement. */ int find_matching_case (struct executable_statement **ep, struct packet *packet, struct lease *lease, struct client_state *client_state, struct option_state *in_options, struct option_state *out_options, struct binding_scope **scope, struct expression *expr, struct executable_statement *stmt) { int status, sub; struct executable_statement *s; unsigned long foo; if (is_data_expression (expr)) { struct executable_statement *e; struct data_string cd, ds; memset (&ds, 0, sizeof ds); memset (&cd, 0, sizeof cd); status = (evaluate_data_expression (&ds, packet, lease, client_state, in_options, out_options, scope, expr, MDL)); if (status) { for (s = stmt; s; s = s -> next) { if (s -> op == case_statement) { sub = (evaluate_data_expression (&cd, packet, lease, client_state, in_options, out_options, scope, s -> data.c_case, MDL)); if (sub && cd.len == ds.len && !memcmp (cd.data, ds.data, cd.len)) { data_string_forget (&cd, MDL); data_string_forget (&ds, MDL); executable_statement_reference (ep, s -> next, MDL); return 1; } data_string_forget (&cd, MDL); } } data_string_forget (&ds, MDL); } } else { unsigned long n, c; status = evaluate_numeric_expression (&n, packet, lease, client_state, in_options, out_options, scope, expr); if (status) { for (s = stmt; s; s = s -> next) { if (s -> op == case_statement) { sub = (evaluate_numeric_expression (&c, packet, lease, client_state, in_options, out_options, scope, s -> data.c_case)); if (sub && n == c) { executable_statement_reference (ep, s -> next, MDL); return 1; } } } } } /* If we didn't find a matching case statement, look for a default statement and return the statement following it. */ for (s = stmt; s; s = s -> next) if (s -> op == default_statement) break; if (s) { executable_statement_reference (ep, s -> next, MDL); return 1; } return 0; } int executable_statement_foreach (struct executable_statement *stmt, int (*callback) (struct executable_statement *, void *, int), void *vp, int condp) { struct executable_statement *foo; int ok = 0; int result; for (foo = stmt; foo; foo = foo -> next) { if ((*callback) (foo, vp, condp) != 0) ok = 1; switch (foo -> op) { case null_statement: break; case if_statement: if (executable_statement_foreach (foo -> data.ie.tc, callback, vp, 1)) ok = 1; if (executable_statement_foreach (foo -> data.ie.fc, callback, vp, 1)) ok = 1; break; case add_statement: break; case eval_statement: break; case break_statement: break; case default_option_statement: break; case supersede_option_statement: break; case append_option_statement: break; case prepend_option_statement: break; case send_option_statement: break; case statements_statement: if ((executable_statement_foreach (foo -> data.statements, callback, vp, condp))) ok = 1; break; case on_statement: if ((executable_statement_foreach (foo -> data.on.statements, callback, vp, 1))) ok = 1; break; case switch_statement: if ((executable_statement_foreach (foo -> data.s_switch.statements, callback, vp, 1))) ok = 1; break; case case_statement: break; case default_statement: break; case set_statement: break; case unset_statement: break; case let_statement: if ((executable_statement_foreach (foo -> data.let.statements, callback, vp, 0))) ok = 1; break; case define_statement: break; case log_statement: case return_statement: break; } } return ok; }