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/*++
/* NAME
/* command 3
/* SUMMARY
/* message delivery to shell command
/* SYNOPSIS
/* #include "local.h"
/*
/* int deliver_command(state, usr_attr, command)
/* LOCAL_STATE state;
/* USER_ATTR exp_attr;
/* const char *command;
/* DESCRIPTION
/* deliver_command() runs a command with a message as standard
/* input. A limited amount of standard output and standard error
/* output is captured for diagnostics purposes.
/* Duplicate commands for the same recipient are suppressed.
/* A limited amount of information is exported via the environment:
/* HOME, SHELL, LOGNAME, USER, EXTENSION, DOMAIN, RECIPIENT (entire
/* address) LOCAL (just the local part), SENDER, and ENVID
/* (see RFC 3461). The exported
/* information is censored with var_cmd_filter.
/*
/* Arguments:
/* .IP state
/* The attributes that specify the message, recipient and more.
/* Attributes describing the alias, include or forward expansion.
/* A table with the results from expanding aliases or lists.
/* .IP usr_attr
/* Attributes describing user rights and environment.
/* .IP command
/* The shell command to be executed. If possible, the command is
/* executed without actually invoking a shell. if the command is
/* the mailbox_command, it is subjected to $name expansion.
/* DIAGNOSTICS
/* deliver_command() returns non-zero when delivery should be
/* tried again,
/* SEE ALSO
/* mailbox(3) deliver to mailbox
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
/* Utility library. */
#include <msg.h>
#include <htable.h>
#include <vstring.h>
#include <vstream.h>
#include <argv.h>
#include <mac_parse.h>
/* Global library. */
#include <defer.h>
#include <bounce.h>
#include <sent.h>
#include <been_here.h>
#include <mail_params.h>
#include <pipe_command.h>
#include <mail_copy.h>
#include <dsn_util.h>
#include <mail_parm_split.h>
/* Application-specific. */
#include "local.h"
/* deliver_command - deliver to shell command */
int deliver_command(LOCAL_STATE state, USER_ATTR usr_attr, const char *command)
{
const char *myname = "deliver_command";
DSN_BUF *why = state.msg_attr.why;
int cmd_status;
int deliver_status;
ARGV *env;
int copy_flags;
char **cpp;
char *cp;
ARGV *export_env;
VSTRING *exec_dir;
int expand_status;
/*
* Make verbose logging easier to understand.
*/
state.level++;
if (msg_verbose)
MSG_LOG_STATE(myname, state);
/*
* DUPLICATE ELIMINATION
*
* Skip this command if it was already delivered to as this user.
*/
if (been_here(state.dup_filter, "command %s:%ld %s",
state.msg_attr.user, (long) usr_attr.uid, command))
return (0);
/*
* Don't deliver a trace-only request.
*/
if (DEL_REQ_TRACE_ONLY(state.request->flags)) {
dsb_simple(why, "2.0.0", "delivers to command: %s", command);
return (sent(BOUNCE_FLAGS(state.request),
SENT_ATTR(state.msg_attr)));
}
/*
* DELIVERY RIGHTS
*
* Choose a default uid and gid when none have been selected (i.e. values
* are still zero).
*/
if (usr_attr.uid == 0 && (usr_attr.uid = var_default_uid) == 0)
msg_panic("privileged default user id");
if (usr_attr.gid == 0 && (usr_attr.gid = var_default_gid) == 0)
msg_panic("privileged default group id");
/*
* Deliver.
*/
copy_flags = MAIL_COPY_FROM | MAIL_COPY_RETURN_PATH
| MAIL_COPY_ORIG_RCPT;
if (local_deliver_hdr_mask & DELIVER_HDR_CMD)
copy_flags |= MAIL_COPY_DELIVERED;
if (vstream_fseek(state.msg_attr.fp, state.msg_attr.offset, SEEK_SET) < 0)
msg_fatal("%s: seek queue file %s: %m",
myname, VSTREAM_PATH(state.msg_attr.fp));
/*
* Pass additional environment information. XXX This should be
* configurable. However, passing untrusted information via environment
* parameters opens up a whole can of worms. Lesson from web servers:
* don't let any network data even near a shell. It causes trouble.
*/
env = argv_alloc(1);
if (usr_attr.home)
argv_add(env, "HOME", usr_attr.home, ARGV_END);
argv_add(env,
"LOGNAME", state.msg_attr.user,
"USER", state.msg_attr.user,
"SENDER", state.msg_attr.sender,
"RECIPIENT", state.msg_attr.rcpt.address,
"LOCAL", state.msg_attr.local,
ARGV_END);
if (usr_attr.shell)
argv_add(env, "SHELL", usr_attr.shell, ARGV_END);
if (state.msg_attr.domain)
argv_add(env, "DOMAIN", state.msg_attr.domain, ARGV_END);
if (state.msg_attr.extension)
argv_add(env, "EXTENSION", state.msg_attr.extension, ARGV_END);
if (state.msg_attr.rcpt.orig_addr && state.msg_attr.rcpt.orig_addr[0])
argv_add(env, "ORIGINAL_RECIPIENT", state.msg_attr.rcpt.orig_addr,
ARGV_END);
if (state.request->dsn_envid[0])
argv_add(env, "ENVID", state.request->dsn_envid, ARGV_END);
#define EXPORT_REQUEST(name, value) \
if ((value)[0]) argv_add(env, (name), (value), ARGV_END);
EXPORT_REQUEST("CLIENT_HOSTNAME", state.msg_attr.request->client_name);
EXPORT_REQUEST("CLIENT_ADDRESS", state.msg_attr.request->client_addr);
EXPORT_REQUEST("CLIENT_HELO", state.msg_attr.request->client_helo);
EXPORT_REQUEST("CLIENT_PROTOCOL", state.msg_attr.request->client_proto);
EXPORT_REQUEST("SASL_METHOD", state.msg_attr.request->sasl_method);
EXPORT_REQUEST("SASL_SENDER", state.msg_attr.request->sasl_sender);
EXPORT_REQUEST("SASL_USERNAME", state.msg_attr.request->sasl_username);
argv_terminate(env);
/*
* Censor out undesirable characters from exported data.
*/
for (cpp = env->argv; *cpp; cpp += 2)
for (cp = cpp[1]; *(cp += strspn(cp, var_cmd_exp_filter)) != 0;)
*cp++ = '_';
/*
* Evaluate the command execution directory. Defer delivery if expansion
* fails.
*/
export_env = mail_parm_split(VAR_EXPORT_ENVIRON, var_export_environ);
exec_dir = vstring_alloc(10);
expand_status = local_expand(exec_dir, var_exec_directory,
&state, &usr_attr, var_exec_exp_filter);
if (expand_status & MAC_PARSE_ERROR) {
cmd_status = PIPE_STAT_DEFER;
dsb_simple(why, "4.3.5", "mail system configuration error");
msg_warn("bad parameter value syntax for %s: %s",
VAR_EXEC_DIRECTORY, var_exec_directory);
} else {
cmd_status = pipe_command(state.msg_attr.fp, why,
CA_PIPE_CMD_UID(usr_attr.uid),
CA_PIPE_CMD_GID(usr_attr.gid),
CA_PIPE_CMD_COMMAND(command),
CA_PIPE_CMD_COPY_FLAGS(copy_flags),
CA_PIPE_CMD_SENDER(state.msg_attr.sender),
CA_PIPE_CMD_ORIG_RCPT(state.msg_attr.rcpt.orig_addr),
CA_PIPE_CMD_DELIVERED(state.msg_attr.delivered),
CA_PIPE_CMD_TIME_LIMIT(var_command_maxtime),
CA_PIPE_CMD_ENV(env->argv),
CA_PIPE_CMD_EXPORT(export_env->argv),
CA_PIPE_CMD_SHELL(var_local_cmd_shell),
CA_PIPE_CMD_CWD(*STR(exec_dir) ?
STR(exec_dir) : (char *) 0),
CA_PIPE_CMD_END);
}
vstring_free(exec_dir);
argv_free(export_env);
argv_free(env);
/*
* Depending on the result, bounce or defer the message.
*/
switch (cmd_status) {
case PIPE_STAT_OK:
dsb_simple(why, "2.0.0", "delivered to command: %s", command);
deliver_status = sent(BOUNCE_FLAGS(state.request),
SENT_ATTR(state.msg_attr));
break;
case PIPE_STAT_BOUNCE:
case PIPE_STAT_DEFER:
/* Account for possible owner- sender address override. */
deliver_status = bounce_workaround(state);
break;
case PIPE_STAT_CORRUPT:
deliver_status = DEL_STAT_DEFER;
break;
default:
msg_panic("%s: bad status %d", myname, cmd_status);
/* NOTREACHED */
}
return (deliver_status);
}
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