-/* $Cambridge: exim/src/src/smtp_in.c,v 1.53 2007/01/30 11:45:20 ph10 Exp $ */
+/* $Cambridge: exim/src/src/smtp_in.c,v 1.55 2007/02/20 15:58:02 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
static int sync_cmd_limit;
static int smtp_write_error = 0;
+static uschar *smtp_data_buffer;
+static uschar *smtp_cmd_data;
+
/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
final fields of all except AUTH are forced TRUE at the start of a new message
setup, to allow one of each between messages that is not counted as a nonmail
+
/*************************************************
* Read one command line *
*************************************************/
!sender_host_notsocket) /* Really is a socket */
return BADSYN_CMD;
- /* Point after the command, but don't skip over leading spaces till after
- the following test, so that if it fails, the command name can easily be
- logged. */
+ /* The variables $smtp_command and $smtp_command_argument point into the
+ unmodified input buffer. A copy of the latter is taken for actual
+ processing, so that it can be chopped up into separate parts if necessary,
+ for example, when processing a MAIL command options such as SIZE that can
+ follow the sender address. */
smtp_cmd_argument = smtp_cmd_buffer + p->len;
+ while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
+ Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
+ smtp_cmd_data = smtp_data_buffer;
/* Count non-mail commands from those hosts that are controlled in this
way. The default is all hosts. We don't waste effort checking the list
return TOO_MANY_NONMAIL_CMD;
}
- /* Get the data pointer over leading spaces and return; if there is data
- for a command that does not expect it, give the error centrally here. */
+ /* If there is data for a command that does not expect it, generate the
+ error here. */
- while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
- return (p->has_arg || *smtp_cmd_argument == 0)? p->cmd : BADARG_CMD;
+ return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
}
}
+/*************************************************
+* Recheck synchronization *
+*************************************************/
+
+/* Synchronization checks can never be perfect because a packet may be on its
+way but not arrived when the check is done. Such checks can in any case only be
+done when TLS is not in use. Normally, the checks happen when commands are
+read: Exim ensures that there is no more input in the input buffer. In normal
+cases, the response to the command will be fast, and there is no further check.
+
+However, for some commands an ACL is run, and that can include delays. In those
+cases, it is useful to do another check on the input just before sending the
+response. This also applies at the start of a connection. This function does
+that check by means of the select() function, as long as the facility is not
+disabled or inappropriate. A failure of select() is ignored.
+
+When there is unwanted input, we read it so that it appears in the log of the
+error.
+
+Arguments: none
+Returns: TRUE if all is well; FALSE if there is input pending
+*/
+
+static BOOL
+check_sync(void)
+{
+int fd, rc;
+fd_set fds;
+struct timeval tzero;
+
+if (!smtp_enforce_sync || sender_host_address == NULL ||
+ sender_host_notsocket || tls_active >= 0)
+ return TRUE;
+
+fd = fileno(smtp_in);
+FD_ZERO(&fds);
+FD_SET(fd, &fds);
+tzero.tv_sec = 0;
+tzero.tv_usec = 0;
+rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
+
+if (rc <= 0) return TRUE; /* Not ready to read */
+rc = smtp_getc();
+if (rc < 0) return TRUE; /* End of file or error */
+
+smtp_ungetc(rc);
+rc = smtp_inend - smtp_inptr;
+if (rc > 150) rc = 150;
+smtp_inptr[rc] = 0;
+return FALSE;
+}
+
+
+
/*************************************************
* Forced closedown of call *
*************************************************/
* Extract SMTP command option *
*************************************************/
-/* This function picks the next option setting off the end of smtp_cmd_argument. It
+/* This function picks the next option setting off the end of smtp_cmd_data. It
is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
things that can appear there.
extract_option(uschar **name, uschar **value)
{
uschar *n;
-uschar *v = smtp_cmd_argument + Ustrlen(smtp_cmd_argument) -1;
+uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
while (isspace(*v)) v--;
v[1] = 0;
-while (v > smtp_cmd_argument && *v != '=' && !isspace(*v)) v--;
+while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--;
if (*v != '=') return FALSE;
n = v;
case HELO_CMD:
case EHLO_CMD:
- check_helo(smtp_cmd_argument);
+ check_helo(smtp_cmd_data);
/* Fall through */
case RSET_CMD:
/* The function moan_smtp_batch() does not return. */
moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
- if (smtp_cmd_argument[0] == 0)
+ if (smtp_cmd_data[0] == 0)
/* The function moan_smtp_batch() does not return. */
moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
/* Apply SMTP rewrite */
raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_argument, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
- US"", global_rewrite_rules) : smtp_cmd_argument;
+ rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
+ US"", global_rewrite_rules) : smtp_cmd_data;
/* Extract the address; the TRUE flag allows <> as valid */
/* The function moan_smtp_batch() does not return. */
moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
- if (smtp_cmd_argument[0] == 0)
+ if (smtp_cmd_data[0] == 0)
/* The function moan_smtp_batch() does not return. */
moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
recipient address */
recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_argument, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_argument;
+ rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules) : smtp_cmd_data;
/* rfc821_domains = TRUE; << no longer needed */
recipient = parse_extract_address(recipient, &errmess, &start, &end,
acl_var_c = NULL;
-/* Allow for trailing 0 in the command buffer. */
+/* Allow for trailing 0 in the command and data buffers. */
-smtp_cmd_buffer = (uschar *)malloc(smtp_cmd_buffer_size + 1);
+smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2);
if (smtp_cmd_buffer == NULL)
log_write(0, LOG_MAIN|LOG_PANIC_DIE,
"malloc() failed for SMTP command buffer");
+smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1;
/* For batched input, the protocol setting can be overridden from the
command line by a trusted caller. */
/* Before we write the banner, check that there is no input pending, unless
this synchronisation check is disabled. */
-if (smtp_enforce_sync && sender_host_address != NULL && !sender_host_notsocket)
+if (!check_sync())
{
- fd_set fds;
- struct timeval tzero;
- tzero.tv_sec = 0;
- tzero.tv_usec = 0;
- FD_ZERO(&fds);
- FD_SET(fileno(smtp_in), &fds);
- if (select(fileno(smtp_in) + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL,
- &tzero) > 0)
- {
- int rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
- if (rc > 0)
- {
- if (rc > 150) rc = 150;
- smtp_inbuffer[rc] = 0;
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
- "synchronization error (input sent without waiting for greeting): "
- "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
- string_printing(smtp_inbuffer));
- smtp_printf("554 SMTP synchronization error\r\n");
- return FALSE;
- }
- }
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
+ "synchronization error (input sent without waiting for greeting): "
+ "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
+ string_printing(smtp_inptr));
+ smtp_printf("554 SMTP synchronization error\r\n");
+ return FALSE;
}
/* Now output the banner */
#endif
(where == ACL_WHERE_PREDATA)? US"DATA" :
(where == ACL_WHERE_DATA)? US"after DATA" :
- (smtp_cmd_argument == NULL)?
+ (smtp_cmd_data == NULL)?
string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) :
- string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_argument);
+ string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data);
if (drop) rc = FAIL;
/* Find the name of the requested authentication mechanism. */
- s = smtp_cmd_argument;
- while ((c = *smtp_cmd_argument) != 0 && !isspace(c))
+ s = smtp_cmd_data;
+ while ((c = *smtp_cmd_data) != 0 && !isspace(c))
{
if (!isalnum(c) && c != '-' && c != '_')
{
US"invalid character in authentication mechanism name");
goto COMMAND_LOOP;
}
- smtp_cmd_argument++;
+ smtp_cmd_data++;
}
/* If not at the end of the line, we must be at white space. Terminate the
name and move the pointer on to any data that may be present. */
- if (*smtp_cmd_argument != 0)
+ if (*smtp_cmd_data != 0)
{
- *smtp_cmd_argument++ = 0;
- while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
+ *smtp_cmd_data++ = 0;
+ while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
}
/* Search for an authentication mechanism which is configured for use
expand_nmax = 0;
expand_nlength[0] = 0; /* $0 contains nothing */
- c = (au->info->servercode)(au, smtp_cmd_argument);
+ c = (au->info->servercode)(au, smtp_cmd_data);
if (au->set_id != NULL) set_id = expand_string(au->set_id);
expand_nmax = -1; /* Reset numeric variables */
for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
/* Reject the HELO if its argument was invalid or non-existent. A
successful check causes the argument to be saved in malloc store. */
- if (!check_helo(smtp_cmd_argument))
+ if (!check_helo(smtp_cmd_data))
{
smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello);
if (!sender_host_unknown)
{
BOOL old_helo_verified = helo_verified;
- uschar *p = smtp_cmd_argument;
+ uschar *p = smtp_cmd_data;
while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
*p = 0;
spf_init(sender_helo_name, sender_host_address);
#endif
- /* Apply an ACL check if one is defined */
+ /* Apply an ACL check if one is defined; afterwards, recheck
+ synchronization in case the client started sending in a delay. */
if (acl_smtp_helo != NULL)
{
host_build_sender_fullhost(); /* Rebuild */
break;
}
+ else if (!check_sync()) goto SYNC_FAILURE;
}
/* Generate an OK reply. The default string includes the ident if present,
break;
}
- if (smtp_cmd_argument[0] == 0)
+ if (smtp_cmd_data[0] == 0)
{
done = synprot_error(L_smtp_protocol_error, 501, NULL,
US"MAIL must have an address operand");
TRUE flag allows "<>" as a sender address. */
raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_argument, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_argument;
+ rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules) : smtp_cmd_data;
/* rfc821_domains = TRUE; << no longer needed */
raw_sender =
if (raw_sender == NULL)
{
- done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_argument, errmess);
+ done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
break;
}
else
{
smtp_printf("501 %s: sender address must contain a domain\r\n",
- smtp_cmd_argument);
+ smtp_cmd_data);
log_write(L_smtp_syntax_error,
LOG_MAIN|LOG_REJECT,
"unqualified sender rejected: <%s> %s%s",
}
}
- /* Apply an ACL check if one is defined, before responding */
+ /* Apply an ACL check if one is defined, before responding. Afterwards,
+ when pipelining is not advertised, do another sync check in case the ACL
+ delayed and the client started sending in the meantime. */
- rc = (acl_smtp_mail == NULL)? OK :
- acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
+ if (acl_smtp_mail == NULL) rc = OK; else
+ {
+ rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
+ if (rc == OK && !pipelining_advertised && !check_sync())
+ goto SYNC_FAILURE;
+ }
if (rc == OK || rc == DISCARD)
{
/* Check for an operand */
- if (smtp_cmd_argument[0] == 0)
+ if (smtp_cmd_data[0] == 0)
{
done = synprot_error(L_smtp_syntax_error, 501, NULL,
US"RCPT must have an address operand");
as a recipient address */
recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_argument, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_argument;
+ rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules) : smtp_cmd_data;
/* rfc821_domains = TRUE; << no longer needed */
recipient = parse_extract_address(recipient, &errmess, &start, &end,
if (recipient == NULL)
{
- done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_argument, errmess);
+ done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
rcpt_fail_count++;
break;
}
{
rcpt_fail_count++;
smtp_printf("501 %s: recipient address must contain a domain\r\n",
- smtp_cmd_argument);
+ smtp_cmd_data);
log_write(L_smtp_syntax_error,
LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: "
"<%s> %s%s", recipient, host_and_ident(TRUE),
}
/* If the MAIL ACL discarded all the recipients, we bypass ACL checking
- for them. Otherwise, check the access control list for this recipient. */
+ for them. Otherwise, check the access control list for this recipient. As
+ there may be a delay in this, re-check for a synchronization error
+ afterwards, unless pipelining was advertised. */
- rc = recipients_discarded? DISCARD :
- acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg, &log_msg);
+ if (recipients_discarded) rc = DISCARD; else
+ {
+ rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
+ &log_msg);
+ if (rc == OK && !pipelining_advertised && !check_sync())
+ goto SYNC_FAILURE;
+ }
/* The ACL was happy */
break;
}
+ /* If there is an ACL, re-check the synchronization afterwards, since the
+ ACL may have delayed. */
+
if (acl_smtp_predata == NULL) rc = OK; else
{
enable_dollar_recipients = TRUE;
rc = acl_check(ACL_WHERE_PREDATA, NULL, acl_smtp_predata, &user_msg,
&log_msg);
enable_dollar_recipients = FALSE;
+ if (rc == OK && !check_sync()) goto SYNC_FAILURE;
}
if (rc == OK)
else
done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
-
break;
uschar *s = NULL;
/* rfc821_domains = TRUE; << no longer needed */
- address = parse_extract_address(smtp_cmd_argument, &errmess, &start, &end,
+ address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end,
&recipient_domain, FALSE);
/* rfc821_domains = FALSE; << no longer needed */
{
BOOL save_log_testing_mode = log_testing_mode;
address_test_mode = log_testing_mode = TRUE;
- (void) verify_address(deliver_make_addr(smtp_cmd_argument, FALSE),
+ (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE),
smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1,
NULL, NULL, NULL);
address_test_mode = FALSE;
/* Compute the serialization key for this command. */
- etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_argument);
+ etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data);
/* If a command has been specified for running as a result of ETRN, we
permit any argument to ETRN. If not, only the # standard form is permitted,
uschar *error;
BOOL rc;
etrn_command = smtp_etrn_command;
- deliver_domain = smtp_cmd_argument;
+ deliver_domain = smtp_cmd_data;
rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL,
US"ETRN processing", &error);
deliver_domain = NULL;
else
{
- if (*smtp_cmd_argument++ != '#')
+ if (*smtp_cmd_data++ != '#')
{
done = synprot_error(L_smtp_syntax_error, 501, NULL,
US"argument must begin with #");
}
etrn_command = US"exim -R";
argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R",
- smtp_cmd_argument);
+ smtp_cmd_data);
}
/* If we are host-testing, don't actually do anything. */
if (smtp_etrn_serialize && !enq_start(etrn_serialize_key))
{
- smtp_printf("458 Already processing %s\r\n", smtp_cmd_argument);
+ smtp_printf("458 Already processing %s\r\n", smtp_cmd_data);
break;
}
case BADSYN_CMD:
+ SYNC_FAILURE:
if (smtp_inend >= smtp_inbuffer + in_buffer_size)
smtp_inend = smtp_inbuffer + in_buffer_size - 1;
c = smtp_inend - smtp_inptr;
case TOO_MANY_NONMAIL_CMD:
+ s = smtp_cmd_buffer;
+ while (*s != 0 && !isspace(*s)) s++;
incomplete_transaction_log(US"too many non-mail commands");
log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
"nonmail commands (last was \"%.*s\")", host_and_ident(FALSE),
- smtp_cmd_argument - smtp_cmd_buffer, smtp_cmd_buffer);
+ s - smtp_cmd_buffer, smtp_cmd_buffer);
smtp_printf("554 Too many nonmail commands\r\n");
done = 1; /* Pretend eof - drops connection */
break;