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|
/*++
/* NAME
/* dotforward 3
/* SUMMARY
/* $HOME/.forward file expansion
/* SYNOPSIS
/* #include "local.h"
/*
/* int deliver_dotforward(state, usr_attr, statusp)
/* LOCAL_STATE state;
/* USER_ATTR usr_attr;
/* int *statusp;
/* DESCRIPTION
/* deliver_dotforward() delivers a message to the destinations
/* listed in a recipient's .forward file(s) as specified through
/* the forward_path configuration parameter. The result is
/* zero when no acceptable .forward file was found, or when
/* a recipient is listed in her own .forward file. Expansions
/* are scrutinized with the forward_expansion_filter parameter.
/*
/* Arguments:
/* .IP state
/* Message delivery attributes (sender, recipient etc.).
/* Attributes describing alias, include or forward expansion.
/* A table with the results from expanding aliases or lists.
/* A table with delivered-to: addresses taken from the message.
/* .IP usr_attr
/* Attributes describing user rights and environment.
/* .IP statusp
/* Message delivery status. See below.
/* DIAGNOSTICS
/* Fatal errors: out of memory. Warnings: bad $HOME/.forward
/* file type, permissions or ownership. The message delivery
/* status is non-zero when delivery should be tried again.
/* SEE ALSO
/* include(3) include file processor.
/* 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 <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#ifdef USE_PATHS_H
#include <paths.h>
#endif
#include <string.h>
/* Utility library. */
#include <msg.h>
#include <vstring.h>
#include <vstream.h>
#include <htable.h>
#include <open_as.h>
#include <lstat_as.h>
#include <iostuff.h>
#include <stringops.h>
#include <mymalloc.h>
#include <mac_expand.h>
/* Global library. */
#include <mypwd.h>
#include <bounce.h>
#include <defer.h>
#include <been_here.h>
#include <mail_params.h>
#include <mail_conf.h>
#include <ext_prop.h>
#include <sent.h>
#include <dsn_mask.h>
#include <trace.h>
/* Application-specific. */
#include "local.h"
#define NO 0
#define YES 1
/* deliver_dotforward - expand contents of .forward file */
int deliver_dotforward(LOCAL_STATE state, USER_ATTR usr_attr, int *statusp)
{
const char *myname = "deliver_dotforward";
struct stat st;
VSTRING *path;
struct mypasswd *mypwd;
int fd;
VSTREAM *fp;
int status;
int forward_found = NO;
int lookup_status;
int addr_count;
char *saved_forward_path;
char *lhs;
char *next;
int expand_status;
int saved_notify;
/*
* Make verbose logging easier to understand.
*/
state.level++;
if (msg_verbose)
MSG_LOG_STATE(myname, state);
/*
* Skip this module if per-user forwarding is disabled.
*/
if (*var_forward_path == 0)
return (NO);
/*
* Skip non-existing users. The mailbox delivery routine will catch the
* error.
*/
if ((errno = mypwnam_err(state.msg_attr.user, &mypwd)) != 0) {
msg_warn("error looking up passwd info for %s: %m",
state.msg_attr.user);
dsb_simple(state.msg_attr.why, "4.0.0", "user lookup error");
*statusp = defer_append(BOUNCE_FLAGS(state.request),
BOUNCE_ATTR(state.msg_attr));
return (YES);
}
if (mypwd == 0)
return (NO);
/*
* From here on no early returns or we have a memory leak.
*/
/*
* EXTERNAL LOOP CONTROL
*
* Set the delivered message attribute to the recipient, so that this
* message will list the correct forwarding address.
*/
if (var_frozen_delivered == 0)
state.msg_attr.delivered = state.msg_attr.rcpt.address;
/*
* DELIVERY RIGHTS
*
* Do not inherit rights from the .forward file owner. Instead, use the
* recipient's rights, and insist that the .forward file is owned by the
* recipient. This is a small but significant difference. Use the
* recipient's rights for all /file and |command deliveries, and pass on
* these rights to command/file destinations in included files. When
* these are the rights of root, the /file and |command delivery routines
* will use unprivileged default rights instead. Better safe than sorry.
*/
SET_USER_ATTR(usr_attr, mypwd, state.level);
/*
* DELIVERY POLICY
*
* Update the expansion type attribute so that we can decide if deliveries
* to |command and /file/name are allowed at all.
*/
state.msg_attr.exp_type = EXPAND_TYPE_FWD;
/*
* WHERE TO REPORT DELIVERY PROBLEMS
*
* Set the owner attribute so that 1) include files won't set the sender to
* be this user and 2) mail forwarded to other local users will be
* resubmitted as a new queue file.
*/
state.msg_attr.owner = state.msg_attr.user;
/*
* Search the forward_path for an existing forward file.
*
* If unmatched extensions should never be propagated, or if a forward file
* name includes the address extension, don't propagate the extension to
* the recipient addresses.
*/
status = 0;
path = vstring_alloc(100);
saved_forward_path = mystrdup(var_forward_path);
next = saved_forward_path;
lookup_status = -1;
while ((lhs = mystrtok(&next, CHARS_COMMA_SP)) != 0) {
expand_status = local_expand(path, lhs, &state, &usr_attr,
var_fwd_exp_filter);
if ((expand_status & (MAC_PARSE_ERROR | MAC_PARSE_UNDEF)) == 0) {
lookup_status =
lstat_as(STR(path), &st, usr_attr.uid, usr_attr.gid);
if (msg_verbose)
msg_info("%s: path %s expand_status %d look_status %d", myname,
STR(path), expand_status, lookup_status);
if (lookup_status >= 0) {
if ((expand_status & LOCAL_EXP_EXTENSION_MATCHED) != 0
|| (local_ext_prop_mask & EXT_PROP_FORWARD) == 0)
state.msg_attr.unmatched = 0;
break;
}
}
}
/*
* Process the forward file.
*
* Assume that usernames do not have file system meta characters. Open the
* .forward file as the user. Ignore files that aren't regular files,
* files that are owned by the wrong user, or files that have world write
* permission enabled.
*
* DUPLICATE/LOOP ELIMINATION
*
* If this user includes (an alias of) herself in her own .forward file,
* deliver to the user instead.
*/
if (lookup_status >= 0) {
/*
* Don't expand a verify-only request.
*/
if (state.request->flags & DEL_REQ_FLAG_MTA_VRFY) {
dsb_simple(state.msg_attr.why, "2.0.0",
"forward via file: %s", STR(path));
*statusp = sent(BOUNCE_FLAGS(state.request),
SENT_ATTR(state.msg_attr));
forward_found = YES;
} else if (been_here(state.dup_filter, "forward %s", STR(path)) == 0) {
state.msg_attr.exp_from = state.msg_attr.local;
if (S_ISREG(st.st_mode) == 0) {
msg_warn("file %s is not a regular file", STR(path));
} else if (st.st_uid != 0 && st.st_uid != usr_attr.uid) {
msg_warn("file %s has bad owner uid %ld",
STR(path), (long) st.st_uid);
} else if (st.st_mode & 002) {
msg_warn("file %s is world writable", STR(path));
} else if ((fd = open_as(STR(path), O_RDONLY, 0, usr_attr.uid, usr_attr.gid)) < 0) {
msg_warn("cannot open file %s: %m", STR(path));
} else {
/*
* XXX DSN. When delivering to an alias (i.e. the envelope
* sender address is not replaced) any ENVID, RET, or ORCPT
* parameters are propagated to all forwarding addresses
* associated with that alias. The NOTIFY parameter is
* propagated to the forwarding addresses, except that any
* SUCCESS keyword is removed.
*/
close_on_exec(fd, CLOSE_ON_EXEC);
addr_count = 0;
fp = vstream_fdopen(fd, O_RDONLY);
saved_notify = state.msg_attr.rcpt.dsn_notify;
state.msg_attr.rcpt.dsn_notify =
(saved_notify == DSN_NOTIFY_SUCCESS ?
DSN_NOTIFY_NEVER : saved_notify & ~DSN_NOTIFY_SUCCESS);
status = deliver_token_stream(state, usr_attr, fp, &addr_count);
if (vstream_fclose(fp))
msg_warn("close file %s: %m", STR(path));
if (addr_count > 0) {
forward_found = YES;
been_here(state.dup_filter, "forward-done %s", STR(path));
/*
* XXX DSN. When delivering to an alias (i.e. the
* envelope sender address is not replaced) and the
* original NOTIFY parameter for the alias contained the
* SUCCESS keyword, an "expanded" DSN is issued for the
* alias.
*/
if (status == 0 && (saved_notify & DSN_NOTIFY_SUCCESS)) {
state.msg_attr.rcpt.dsn_notify = saved_notify;
dsb_update(state.msg_attr.why, "2.0.0", "expanded",
DSB_SKIP_RMTA, DSB_SKIP_REPLY,
"alias expanded");
(void) trace_append(BOUNCE_FLAG_NONE,
SENT_ATTR(state.msg_attr));
}
}
}
} else if (been_here_check(state.dup_filter, "forward-done %s", STR(path)) != 0)
forward_found = YES; /* else we're recursive */
}
/*
* Clean up.
*/
vstring_free(path);
myfree(saved_forward_path);
mypwfree(mypwd);
*statusp = status;
return (forward_found);
}
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