Adding upstream version 4.96.upstream/4.96upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 538 insertions, 0 deletions

diff --git a/src/routers/queryprogram.c b/src/routers/queryprogram.c
new file mode 100644
index 0000000..55f03a4
--- /dev/null
+++ b/src/routers/queryprogram.c
@@ -0,0 +1,538 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+#include "../exim.h"
+#include "rf_functions.h"
+#include "queryprogram.h"
+
+
+
+/* Options specific to the queryprogram router. */
+
+optionlist queryprogram_router_options[] = {
+  { "*expand_command_group", opt_bool | opt_hidden,
+      OPT_OFF(queryprogram_router_options_block, expand_cmd_gid) },
+  { "*expand_command_user", opt_bool | opt_hidden,
+      OPT_OFF(queryprogram_router_options_block, expand_cmd_uid) },
+  { "*set_command_group",   opt_bool | opt_hidden,
+      OPT_OFF(queryprogram_router_options_block, cmd_gid_set) },
+  { "*set_command_user",    opt_bool | opt_hidden,
+      OPT_OFF(queryprogram_router_options_block, cmd_uid_set) },
+  { "command",      opt_stringptr,
+      OPT_OFF(queryprogram_router_options_block, command) },
+  { "command_group",opt_expand_gid,
+      OPT_OFF(queryprogram_router_options_block, cmd_gid) },
+  { "command_user", opt_expand_uid,
+      OPT_OFF(queryprogram_router_options_block, cmd_uid) },
+  { "current_directory", opt_stringptr,
+      OPT_OFF(queryprogram_router_options_block, current_directory) },
+  { "timeout",      opt_time,
+      OPT_OFF(queryprogram_router_options_block, timeout) }
+};
+
+/* Size of the options list. An extern variable has to be used so that its
+address can appear in the tables drtables.c. */
+
+int queryprogram_router_options_count =
+  sizeof(queryprogram_router_options)/sizeof(optionlist);
+
+
+#ifdef MACRO_PREDEF
+
+/* Dummy entries */
+queryprogram_router_options_block queryprogram_router_option_defaults = {0};
+void queryprogram_router_init(router_instance *rblock) {}
+int queryprogram_router_entry(router_instance *rblock, address_item *addr,
+  struct passwd *pw, int verify, address_item **addr_local,
+  address_item **addr_remote, address_item **addr_new,
+  address_item **addr_succeed) {return 0;}
+
+#else   /*!MACRO_PREDEF*/
+
+
+/* Default private options block for the queryprogram router. */
+
+queryprogram_router_options_block queryprogram_router_option_defaults = {
+  NULL,         /* command */
+  60*60,        /* timeout */
+  (uid_t)(-1),  /* cmd_uid */
+  (gid_t)(-1),  /* cmd_gid */
+  FALSE,        /* cmd_uid_set */
+  FALSE,        /* cmd_gid_set */
+  US"/",        /* current_directory */
+  NULL,         /* expand_cmd_gid */
+  NULL          /* expand_cmd_uid */
+};
+
+
+
+/*************************************************
+*          Initialization entry point            *
+*************************************************/
+
+/* Called for each instance, after its options have been read, to enable
+consistency checks to be done, or anything else that needs to be set up. */
+
+void
+queryprogram_router_init(router_instance *rblock)
+{
+queryprogram_router_options_block *ob =
+  (queryprogram_router_options_block *)(rblock->options_block);
+
+/* A command must be given */
+
+if (!ob->command)
+  log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
+    "a command specification is required", rblock->name);
+
+/* A uid/gid must be supplied */
+
+if (!ob->cmd_uid_set && !ob->expand_cmd_uid)
+  log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s router:\n  "
+    "command_user must be specified", rblock->name);
+}
+
+
+
+/*************************************************
+*    Process a set of generated new addresses    *
+*************************************************/
+
+/* This function sets up a set of newly generated child addresses and puts them
+on the new address chain.
+
+Arguments:
+  rblock                  router block
+  addr_new                new address chain
+  addr                    original address
+  generated               list of generated addresses
+  addr_prop               the propagated data block, containing errors_to,
+                            header change stuff, and address_data
+
+Returns:         nothing
+*/
+
+static void
+add_generated(router_instance *rblock, address_item **addr_new,
+  address_item *addr, address_item *generated,
+  address_item_propagated *addr_prop)
+{
+while (generated != NULL)
+  {
+  BOOL ignore_error = addr->prop.ignore_error;
+  address_item *next = generated;
+
+  generated = next->next;
+
+  next->parent = addr;
+  next->prop = *addr_prop;
+  next->prop.ignore_error = next->prop.ignore_error || ignore_error;
+  next->start_router = rblock->redirect_router;
+
+  next->next = *addr_new;
+  *addr_new = next;
+
+  if (addr->child_count == USHRT_MAX)
+    log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s router generated more than %d "
+      "child addresses for <%s>", rblock->name, USHRT_MAX, addr->address);
+  addr->child_count++;
+
+  DEBUG(D_route)
+    debug_printf("%s router generated %s\n", rblock->name, next->address);
+  }
+}
+
+
+
+
+/*************************************************
+*              Main entry point                  *
+*************************************************/
+
+/* See local README for interface details. This router returns:
+
+DECLINE
+  . DECLINE returned
+  . self = DECLINE
+
+PASS
+  . PASS returned
+  . timeout of host lookup and pass_on_timeout set
+  . self = PASS
+
+DEFER
+  . verifying the errors address caused a deferment or a big disaster such
+      as an expansion failure (rf_get_errors_address)
+  . expanding a headers_{add,remove} string caused a deferment or another
+      expansion error (rf_get_munge_headers)
+  . a problem in rf_get_transport: no transport when one is needed;
+      failed to expand dynamic transport; failed to find dynamic transport
+  . bad lookup type
+  . problem looking up host (rf_lookup_hostlist)
+  . self = DEFER or FREEZE
+  . failure to set up uid/gid for running the command
+  . failure of transport_set_up_command: too many arguments, expansion fail
+  . failure to create child process
+  . child process crashed or timed out or didn't return data
+  . :defer: in data
+  . DEFER or FREEZE returned
+  . problem in redirection data
+  . unknown transport name or trouble expanding router transport
+
+FAIL
+  . :fail: in data
+  . FAIL returned
+  . self = FAIL
+
+OK
+  . address added to addr_local or addr_remote for delivery
+  . new addresses added to addr_new
+*/
+
+int
+queryprogram_router_entry(
+  router_instance *rblock,        /* data for this instantiation */
+  address_item *addr,             /* address we are working on */
+  struct passwd *pw,              /* passwd entry after check_local_user */
+  int verify,                     /* v_none/v_recipient/v_sender/v_expn */
+  address_item **addr_local,      /* add it to this if it's local */
+  address_item **addr_remote,     /* add it to this if it's remote */
+  address_item **addr_new,        /* put new addresses on here */
+  address_item **addr_succeed)    /* put old address here on success */
+{
+int fd_in, fd_out, len, rc;
+pid_t pid;
+struct passwd *upw = NULL;
+uschar buffer[1024];
+const uschar **argvptr;
+uschar *rword, *rdata, *s;
+address_item_propagated addr_prop;
+queryprogram_router_options_block *ob =
+  (queryprogram_router_options_block *)(rblock->options_block);
+uschar *current_directory = ob->current_directory;
+ugid_block ugid;
+uid_t curr_uid = getuid();
+gid_t curr_gid = getgid();
+uid_t uid = ob->cmd_uid;
+gid_t gid = ob->cmd_gid;
+uid_t *puid = &uid;
+gid_t *pgid = &gid;
+
+DEBUG(D_route) debug_printf("%s router called for %s: domain = %s\n",
+  rblock->name, addr->address, addr->domain);
+
+ugid.uid_set = ugid.gid_set = FALSE;
+
+/* Set up the propagated data block with the current address_data and the
+errors address and extra header stuff. */
+
+bzero(&addr_prop, sizeof(addr_prop));
+addr_prop.address_data = deliver_address_data;
+tree_dup((tree_node **)&addr_prop.variables, addr->prop.variables);
+
+rc = rf_get_errors_address(addr, rblock, verify, &addr_prop.errors_address);
+if (rc != OK) return rc;
+
+rc = rf_get_munge_headers(addr, rblock, &addr_prop.extra_headers,
+  &addr_prop.remove_headers);
+if (rc != OK) return rc;
+
+/* Get the fixed or expanded uid under which the command is to run
+(initialization ensures that one or the other is set). */
+
+if (  !ob->cmd_uid_set
+   && !route_find_expanded_user(ob->expand_cmd_uid, rblock->name, US"router",
+	&upw, &uid, &(addr->message)))
+    return DEFER;
+
+/* Get the fixed or expanded gid, or take the gid from the passwd entry. */
+
+if (!ob->cmd_gid_set)
+  if (ob->expand_cmd_gid)
+    {
+    if (route_find_expanded_group(ob->expand_cmd_gid, rblock->name,
+        US"router", &gid, &(addr->message)))
+      return DEFER;
+    }
+  else if (upw)
+    gid = upw->pw_gid;
+  else
+    {
+    addr->message = string_sprintf("command_user set without command_group "
+      "for %s router", rblock->name);
+    return DEFER;
+    }
+
+DEBUG(D_route) debug_printf("requires uid=%ld gid=%ld current_directory=%s\n",
+  (long int)uid, (long int)gid, current_directory);
+
+/* If we are not running as root, we will not be able to change uid/gid. */
+
+if (curr_uid != root_uid && (uid != curr_uid || gid != curr_gid))
+  {
+  DEBUG(D_route)
+    {
+    debug_printf("not running as root: cannot change uid/gid\n");
+    debug_printf("subprocess will run with uid=%ld gid=%ld\n",
+      (long int)curr_uid, (long int)curr_gid);
+    }
+  puid = pgid = NULL;
+  }
+
+/* Set up the command to run */
+
+if (!transport_set_up_command(&argvptr, /* anchor for arg list */
+    ob->command,                        /* raw command */
+    TRUE,                               /* expand the arguments */
+    0,                                  /* not relevant when... */
+    NULL,                               /* no transporting address */
+    FALSE,				/* args must be untainted */
+    US"queryprogram router",            /* for error messages */
+    &addr->message))                    /* where to put error message */
+  return DEFER;
+
+/* Create the child process, making it a group leader. */
+
+if ((pid = child_open_uid(argvptr, NULL, 0077, puid, pgid, &fd_in, &fd_out,
+			  current_directory, TRUE, US"queryprogram-cmd")) < 0)
+  {
+  addr->message = string_sprintf("%s router couldn't create child process: %s",
+    rblock->name, strerror(errno));
+  return DEFER;
+  }
+
+/* Nothing is written to the standard input. */
+
+(void)close(fd_in);
+
+/* Wait for the process to finish, applying the timeout, and inspect its return
+code. */
+
+if ((rc = child_close(pid, ob->timeout)) != 0)
+  {
+  if (rc > 0)
+    addr->message = string_sprintf("%s router: command returned non-zero "
+      "code %d", rblock->name, rc);
+
+  else if (rc == -256)
+    {
+    addr->message = string_sprintf("%s router: command timed out",
+      rblock->name);
+    killpg(pid, SIGKILL);       /* Kill the whole process group */
+    }
+
+  else if (rc == -257)
+    addr->message = string_sprintf("%s router: wait() failed: %s",
+      rblock->name, strerror(errno));
+
+  else
+    addr->message = string_sprintf("%s router: command killed by signal %d",
+      rblock->name, -rc);
+
+  return DEFER;
+  }
+
+/* Read the pipe to get the command's output, and then close it. */
+
+len = read(fd_out, buffer, sizeof(buffer) - 1);
+(void)close(fd_out);
+
+/* Failure to return any data is an error. */
+
+if (len <= 0)
+  {
+  addr->message = string_sprintf("%s router: command failed to return data",
+    rblock->name);
+  return DEFER;
+  }
+
+/* Get rid of leading and trailing white space, and pick off the first word of
+the result. */
+
+while (len > 0 && isspace(buffer[len-1])) len--;
+buffer[len] = 0;
+
+DEBUG(D_route) debug_printf("command wrote: %s\n", buffer);
+
+rword = buffer;
+while (isspace(*rword)) rword++;
+rdata = rword;
+while (*rdata && !isspace(*rdata)) rdata++;
+if (*rdata) *rdata++ = 0;
+
+/* The word must be a known yield name. If it is "REDIRECT", the rest of the
+line is redirection data, as for a .forward file. It may not contain filter
+data, and it may not contain anything other than addresses (no files, no pipes,
+no specials). */
+
+if (strcmpic(rword, US"REDIRECT") == 0)
+  {
+  int filtertype;
+  redirect_block redirect;
+  address_item *generated = NULL;
+
+  redirect.string = rdata;
+  redirect.isfile = FALSE;
+
+  rc = rda_interpret(&redirect,  /* redirection data */
+    RDO_BLACKHOLE |              /* forbid :blackhole: */
+      RDO_FAIL    |              /* forbid :fail: */
+      RDO_INCLUDE |              /* forbid :include: */
+      RDO_REWRITE,               /* rewrite generated addresses */
+    NULL,                        /* :include: directory not relevant */
+    NULL,                        /* sieve vacation directory not relevant */
+    NULL,                        /* sieve enotify mailto owner not relevant */
+    NULL,                        /* sieve useraddress not relevant */
+    NULL,                        /* sieve subaddress not relevant */
+    &ugid,                       /* uid/gid (but not set) */
+    &generated,                  /* where to hang the results */
+    &addr->message,              /* where to put messages */
+    NULL,                        /* don't skip syntax errors */
+    &filtertype,                 /* not used; will always be FILTER_FORWARD */
+    string_sprintf("%s router", rblock->name));
+
+  switch (rc)
+    {
+    /* FF_DEFER and FF_FAIL can arise only as a result of explicit commands.
+    If a configured message was supplied, allow it to be  included in an SMTP
+    response after verifying. */
+
+    case FF_DEFER:
+      if (!addr->message) addr->message = US"forced defer";
+      else addr->user_message = addr->message;
+      return DEFER;
+
+    case FF_FAIL:
+      add_generated(rblock, addr_new, addr, generated, &addr_prop);
+      if (!addr->message) addr->message = US"forced rejection";
+      else addr->user_message = addr->message;
+      return FAIL;
+
+    case FF_DELIVERED:
+      break;
+
+    case FF_NOTDELIVERED:    /* an empty redirection list is bad */
+      addr->message = US"no addresses supplied";
+    /* Fall through */
+
+    case FF_ERROR:
+    default:
+      addr->basic_errno = ERRNO_BADREDIRECT;
+      addr->message = string_sprintf("error in redirect data: %s", addr->message);
+      return DEFER;
+    }
+
+  /* Handle the generated addresses, if any. */
+
+  add_generated(rblock, addr_new, addr, generated, &addr_prop);
+
+  /* Put the original address onto the succeed queue so that any retry items
+  that get attached to it get processed. */
+
+  addr->next = *addr_succeed;
+  *addr_succeed = addr;
+
+  return OK;
+  }
+
+/* Handle other returns that are not ACCEPT */
+
+if (strcmpic(rword, US"accept") != 0)
+  {
+  if (strcmpic(rword, US"decline") == 0) return DECLINE;
+  if (strcmpic(rword, US"pass") == 0) return PASS;
+  addr->message = string_copy(rdata);                /* data is a message */
+  if (strcmpic(rword, US"fail") == 0)
+    {
+    setflag(addr, af_pass_message);
+    return FAIL;
+    }
+  if (strcmpic(rword, US"freeze") == 0) addr->special_action = SPECIAL_FREEZE;
+  else if (strcmpic(rword, US"defer") != 0)
+    {
+    addr->message = string_sprintf("bad command yield: %s %s", rword, rdata);
+    log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
+    }
+  return DEFER;
+  }
+
+/* The command yielded "ACCEPT". The rest of the string is a number of keyed
+fields from which we can fish out values using the equivalent of the "extract"
+expansion function. */
+
+if ((s = expand_getkeyed(US"data", rdata)) && *s)
+  addr_prop.address_data = string_copy(s);
+
+/* If we found a transport name, find the actual transport */
+
+if ((s = expand_getkeyed(US"transport", rdata)) && *s)
+  {
+  transport_instance *transport;
+  for (transport = transports; transport; transport = transport->next)
+    if (Ustrcmp(transport->name, s) == 0) break;
+  if (!transport)
+    {
+    addr->message = string_sprintf("unknown transport name %s yielded by "
+      "command", s);
+    log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
+    return DEFER;
+    }
+  addr->transport = transport;
+  }
+
+/* No transport given; get the transport from the router configuration. It may
+be fixed or expanded, but there will be an error if it is unset, requested by
+the last argument not being NULL. */
+
+else
+  {
+  if (!rf_get_transport(rblock->transport_name, &rblock->transport, addr,
+       rblock->name, US"transport"))
+    return DEFER;
+  addr->transport = rblock->transport;
+  }
+
+/* See if a host list is given, and if so, look up the addresses. */
+
+if ((s = expand_getkeyed(US"hosts", rdata)) && *s)
+  {
+  int lookup_type = LK_DEFAULT;
+  uschar * ss = expand_getkeyed(US"lookup", rdata);
+
+  if (ss && *ss)
+    {
+    if (Ustrcmp(ss, "byname") == 0) lookup_type = LK_BYNAME;
+    else if (Ustrcmp(ss, "bydns") == 0) lookup_type = LK_BYDNS;
+    else
+      {
+      addr->message = string_sprintf("bad lookup type \"%s\" yielded by "
+        "command", ss);
+      log_write(0, LOG_PANIC, "%s router: %s", rblock->name, addr->message);
+      return DEFER;
+      }
+    }
+
+  host_build_hostlist(&(addr->host_list), s, FALSE);  /* pro tem no randomize */
+
+  rc = rf_lookup_hostlist(rblock, addr, rblock->ignore_target_hosts,
+    lookup_type, hff_defer, addr_new);
+  if (rc != OK) return rc;
+  }
+lookup_value = NULL;
+
+/* Put the errors address, extra headers, and address_data into this address */
+
+addr->prop = addr_prop;
+
+/* Queue the address for local or remote delivery. */
+
+return rf_queue_add(addr, addr_local, addr_remote, rblock, pw) ? OK : DEFER;
+}
+
+#endif   /*!MACRO_PREDEF*/
+/* End of routers/queryprogram.c */