* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2016 */
+/* Copyright (c) University of Cambridge 1995 - 2017 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions for handling an incoming SMTP call. */
we need room to handle large base64-encoded AUTHs for GSSAPI.
*/
-#define smtp_cmd_buffer_size 16384
+#define SMTP_CMD_BUFFER_SIZE 16384
/* Size of buffer for reading SMTP incoming packets */
-#define in_buffer_size 8192
+#define IN_BUFFER_SIZE 8192
/* Structure for SMTP command list */
MAIL_CMD, RCPT_CMD, RSET_CMD,
+ /* This is a dummy to identify the non-sync commands when not pipelining */
+
+ NON_SYNC_CMD_NON_PIPELINING,
+
/* RFC3030 section 2: "After all MAIL and RCPT responses are collected and
processed the message is sent using a series of BDAT commands"
implies that BDAT should be synchronized. However, we see Google, at least,
sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for
- processing of the RPCT response(s). We shall do the same, and not require
- synch for BDAT. */
+ processing of the RCPT response(s). We shall do the same, and not require
+ synch for BDAT. Worse, as the chunk may (very likely will) follow the
+ command-header in the same packet we cannot do the usual "is there any
+ follow-on data after the command line" even for non-pipeline mode.
+ So we'll need an explicit check after reading the expected chunk amount
+ when non-pipe, before sending the ACK. */
BDAT_CMD,
- /* This is a dummy to identify the non-sync commands when not pipelining */
-
- NON_SYNC_CMD_NON_PIPELINING,
-
/* I have been unable to find a statement about the use of pipelining
with AUTH, so to be on the safe side it is here, though I kind of feel
it should be up there with the synchronized commands. */
/* forward declarations */
-int bdat_ungetc(int ch);
-static int smtp_read_command(BOOL check_sync);
+static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
static int synprot_error(int type, int code, uschar *data, uschar *errmess);
static void smtp_quit_handler(uschar **, uschar **);
static void smtp_rset_handler(void);
+/*************************************************
+* 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_in.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(GETC_BUFFER_UNLIMITED);
+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;
+}
+
+
+
+/*************************************************
+* Log incomplete transactions *
+*************************************************/
+
+/* This function is called after a transaction has been aborted by RSET, QUIT,
+connection drops or other errors. It logs the envelope information received
+so far in order to preserve address verification attempts.
+
+Argument: string to indicate what aborted the transaction
+Returns: nothing
+*/
+
+static void
+incomplete_transaction_log(uschar *what)
+{
+if (sender_address == NULL || /* No transaction in progress */
+ !LOGGING(smtp_incomplete_transaction))
+ return;
+
+/* Build list of recipients for logging */
+
+if (recipients_count > 0)
+ {
+ int i;
+ raw_recipients = store_get(recipients_count * sizeof(uschar *));
+ for (i = 0; i < recipients_count; i++)
+ raw_recipients[i] = recipients_list[i].address;
+ raw_recipients_count = recipients_count;
+ }
+
+log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
+ "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
+}
+
+
+
+
/*************************************************
* SMTP version of getc() *
*************************************************/
/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
it flushes the output, and refills the buffer, with a timeout. The signal
handler is set appropriately by the calling function. This function is not used
-after a connection has negotated itself into an TLS/SSL state.
+after a connection has negotiated itself into an TLS/SSL state.
-Arguments: none
+Arguments: lim Maximum amount to read/buffer
Returns: the next character or EOF
*/
int
-smtp_getc(void)
+smtp_getc(unsigned lim)
{
if (smtp_inptr >= smtp_inend)
{
if (!smtp_out) return EOF;
fflush(smtp_out);
if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
+
+ /* Limit amount read, so non-message data is not fed to DKIM */
+
+ rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE, lim));
save_errno = errno;
alarm(0);
if (rc <= 0)
Placed here due to the correlation with the above smtp_getc(), which it wraps,
and also by the need to do smtp command/response handling.
-Arguments: none
+Arguments: lim (ignored)
Returns: the next character or ERR, EOD or EOF
*/
int
-bdat_getc(void)
+bdat_getc(unsigned lim)
{
uschar * user_msg = NULL;
uschar * log_msg;
for(;;)
{
- if (chunking_data_left-- > 0)
- return lwr_receive_getc();
+#ifndef DISABLE_DKIM
+ BOOL dkim_save;
+#endif
+
+ if (chunking_data_left > 0)
+ return lwr_receive_getc(chunking_data_left--);
receive_getc = lwr_receive_getc;
receive_ungetc = lwr_receive_ungetc;
+#ifndef DISABLE_DKIM
+ dkim_save = dkim_collect_input;
+ dkim_collect_input = FALSE;
+#endif
+
+ /* Unless PIPELINING was offered, there should be no next command
+ until after we ack that chunk */
+
+ if (!pipelining_advertised && !check_sync())
+ {
+ incomplete_transaction_log(US"sync failure");
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
+ "(next input sent too soon: pipelining was not advertised): "
+ "rejected \"%s\" %s next input=\"%s\"",
+ smtp_cmd_buffer, host_and_ident(TRUE),
+ string_printing(smtp_inptr));
+ (void) synprot_error(L_smtp_protocol_error, 554, NULL,
+ US"SMTP synchronization error");
+ goto repeat_until_rset;
+ }
/* If not the last, ack the received chunk. The last response is delayed
until after the data ACL decides on it */
return EOD;
}
- chunking_state = CHUNKING_OFFERED;
smtp_printf("250 %u byte chunk received\r\n", chunking_datasize);
+ chunking_state = CHUNKING_OFFERED;
+ DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
/* Expect another BDAT cmd from input. RFC 3030 says nothing about
QUIT, RSET or NOOP but handling them seems obvious */
next_cmd:
- switch(smtp_read_command(TRUE))
+ switch(smtp_read_command(TRUE, 1))
{
default:
(void) synprot_error(L_smtp_protocol_error, 503, NULL,
US"only BDAT permissible after non-LAST BDAT");
repeat_until_rset:
- switch(smtp_read_command(TRUE))
+ switch(smtp_read_command(TRUE, 1))
{
case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
case EOF_CMD: return EOF;
chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
? CHUNKING_LAST : CHUNKING_ACTIVE;
chunking_data_left = chunking_datasize;
+ DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
+ (int)chunking_state, chunking_data_left);
if (chunking_datasize == 0)
if (chunking_state == CHUNKING_LAST)
receive_getc = bdat_getc;
receive_ungetc = bdat_ungetc;
+#ifndef DISABLE_DKIM
+ dkim_collect_input = dkim_save;
+#endif
break; /* to top of main loop */
}
}
}
}
-static void
+void
bdat_flush_data(void)
{
-while (chunking_data_left-- > 0)
- if (lwr_receive_getc() < 0)
+while (chunking_data_left > 0)
+ if (lwr_receive_getc(chunking_data_left--) < 0)
break;
receive_getc = lwr_receive_getc;
receive_ungetc = lwr_receive_ungetc;
if (chunking_state != CHUNKING_LAST)
+ {
chunking_state = CHUNKING_OFFERED;
+ DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
+ }
}
* Check if host is required proxy host *
*************************************************/
/* The function determines if inbound host will be a regular smtp host
-or if it is configured that it must use Proxy Protocol.
+or if it is configured that it must use Proxy Protocol. A local
+connection cannot.
Arguments: none
Returns: bool
check_proxy_protocol_host()
{
int rc;
-/* Cannot configure local connection as a proxy inbound */
-if (sender_host_address == NULL) return proxy_session;
-rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
- sender_host_address, NULL);
-if (rc == OK)
+if ( sender_host_address
+ && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
+ sender_host_address, NULL)) == OK)
{
DEBUG(D_receive)
debug_printf("Detected proxy protocol configured host\n");
}
+/*************************************************
+* Read data until newline or end of buffer *
+*************************************************/
+/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
+read an entire buffer and assume there will be nothing past a proxy protocol
+header. Our approach normally is to use stdio, but again that relies upon
+"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
+reading _nothing_ before client TLS handshake. So we don't want to use the
+usual buffering reads which may read enough to block TLS starting.
+
+So unfortunately we're down to "read one byte at a time, with a syscall each,
+and expect a little overhead", for all proxy-opened connections which are v1,
+just to handle the TLS-on-connect case. Since SSL functions wrap the
+underlying fd, we can't assume that we can feed them any already-read content.
+
+We need to know where to read to, the max capacity, and we'll read until we
+get a CR and one more character. Let the caller scream if it's CR+!LF.
+
+Return the amount read.
+*/
+
+static int
+swallow_until_crlf(int fd, uschar *base, int already, int capacity)
+{
+uschar *to = base + already;
+uschar *cr;
+int have = 0;
+int ret;
+int last = 0;
+
+/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
+up through the \r; for the _normal_ case, we haven't yet seen the \r. */
+
+cr = memchr(base, '\r', already);
+if (cr != NULL)
+ {
+ if ((cr - base) < already - 1)
+ {
+ /* \r and presumed \n already within what we have; probably not
+ actually proxy protocol, but abort cleanly. */
+ return 0;
+ }
+ /* \r is last character read, just need one more. */
+ last = 1;
+ }
+
+while (capacity > 0)
+ {
+ do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
+ if (ret == -1)
+ return -1;
+ have++;
+ if (last)
+ return have;
+ if (*to == '\r')
+ last = 1;
+ capacity--;
+ to++;
+ }
+
+/* reached end without having room for a final newline, abort */
+errno = EOVERFLOW;
+return -1;
+}
+
/*************************************************
* Setup host for proxy protocol *
*************************************************/
Returns: Boolean success
*/
-static BOOL
+static void
setup_proxy_protocol_host()
{
union {
char tmpip6[INET6_ADDRSTRLEN];
struct sockaddr_in6 tmpaddr6;
+/* We can't read "all data until end" because while SMTP is
+server-speaks-first, the TLS handshake is client-speaks-first, so for
+TLS-on-connect ports the proxy protocol header will usually be immediately
+followed by a TLS handshake, and with N TLS libraries, we can't reliably
+reinject data for reading by those. So instead we first read "enough to be
+safely read within the header, and figure out how much more to read".
+For v1 we will later read to the end-of-line, for v2 we will read based upon
+the stated length.
+
+The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
+data is needed total. For v1, where the line looks like:
+PROXY TCPn L3src L3dest SrcPort DestPort \r\n
+
+However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
+We seem to support that. So, if we read 14 octets then we can tell if we're
+v2 or v1. If we're v1, we can continue reading as normal.
+
+If we're v2, we can't slurp up the entire header. We need the length in the
+15th & 16th octets, then to read everything after that.
+
+So to safely handle v1 and v2, with client-sent-first supported correctly,
+we have to do a minimum of 3 read calls, not 1. Eww.
+*/
+
+#define PROXY_INITIAL_READ 14
+#define PROXY_V2_HEADER_SIZE 16
+#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
+# error Code bug in sizes of data to read for proxy usage
+#endif
+
int get_ok = 0;
int size, ret;
int fd = fileno(smtp_in);
const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
-uschar *iptype; /* To display debug info */
+uschar * iptype; /* To display debug info */
struct timeval tv;
struct timeval tvtmp;
socklen_t vslen = sizeof(struct timeval);
+BOOL yield = FALSE;
/* Save current socket timeout values */
get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
- return FALSE;
+ goto bad;
do
{
/* The inbound host was declared to be a Proxy Protocol host, so
- don't do a PEEK into the data, actually slurp it up. */
- ret = recv(fd, &hdr, sizeof(hdr), 0);
+ don't do a PEEK into the data, actually slurp up enough to be
+ "safe". Can't take it all because TLS-on-connect clients follow
+ immediately with TLS handshake. */
+ ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
}
while (ret == -1 && errno == EINTR);
if (ret == -1)
goto proxyfail;
-if (ret >= 16 &&
- memcmp(&hdr.v2, v2sig, 12) == 0)
+/* For v2, handle reading the length, and then the rest. */
+if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
{
- uint8_t ver, cmd;
+ int retmore;
+ uint8_t ver;
+
+ /* First get the length fields. */
+ do
+ {
+ retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
+ } while (retmore == -1 && errno == EINTR);
+ if (retmore == -1)
+ goto proxyfail;
+ ret += retmore;
- /* May 2014: haproxy combined the version and command into one byte to
- allow two full bytes for the length field in order to proxy SSL
- connections. SSL Proxy is not supported in this version of Exim, but
- must still seperate values here. */
ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
- cmd = (hdr.v2.ver_cmd & 0x0f);
+
+ /* May 2014: haproxy combined the version and command into one byte to
+ allow two full bytes for the length field in order to proxy SSL
+ connections. SSL Proxy is not supported in this version of Exim, but
+ must still separate values here. */
if (ver != 0x02)
{
DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
goto proxyfail;
}
- DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
+
/* The v2 header will always be 16 bytes per the spec. */
- size = 16 + hdr.v2.len;
- if (ret < size)
+ size = 16 + ntohs(hdr.v2.len);
+ DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
+ size, (int)sizeof(hdr));
+
+ /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
+ amount that we need. Double-check that the size is not unreasonable, then
+ get the rest. */
+ if (size > sizeof(hdr))
{
- DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
- ret, size);
+ DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
goto proxyfail;
}
+
+ do
+ {
+ do
+ {
+ retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
+ } while (retmore == -1 && errno == EINTR);
+ if (retmore == -1)
+ goto proxyfail;
+ ret += retmore;
+ DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
+ } while (ret < size);
+
+ } /* end scope for getting rest of data for v2 */
+
+/* At this point: if PROXYv2, we've read the exact size required for all data;
+if PROXYv1 then we've read "less than required for any valid line" and should
+read the rest". */
+
+if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
+ {
+ uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
+
switch (cmd)
{
case 0x01: /* PROXY command */
case 0x11: /* TCPv4 address type */
iptype = US"IPv4";
tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
- inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
- if (!string_is_ip_address(US tmpip,NULL))
+ inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip, NULL))
{
DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
goto proxyfail;
sender_host_port = tmpport;
/* Save dest ip/port */
tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
- inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
- if (!string_is_ip_address(US tmpip,NULL))
+ inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip, NULL))
{
DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
goto proxyfail;
case 0x21: /* TCPv6 address type */
iptype = US"IPv6";
memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
- inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
- if (!string_is_ip_address(US tmpip6,NULL))
+ inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6, NULL))
{
DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
goto proxyfail;
sender_host_port = tmpport;
/* Save dest ip/port */
memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
- inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
- if (!string_is_ip_address(US tmpip6,NULL))
+ inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6, NULL))
{
DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
goto proxyfail;
break;
case 0x00: /* LOCAL command */
/* Keep local connection address for LOCAL */
+ iptype = US"local";
break;
default:
DEBUG(D_receive)
goto proxyfail;
}
}
-else if (ret >= 8 &&
- memcmp(hdr.v1.line, "PROXY", 5) == 0)
+else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
{
- uschar *p = string_copy(hdr.v1.line);
- uschar *end = memchr(p, '\r', ret - 1);
+ uschar *p;
+ uschar *end;
uschar *sp; /* Utility variables follow */
int tmp_port;
+ int r2;
char *endc;
- if (!end || end[1] != '\n')
+ /* get the rest of the line */
+ r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
+ if (r2 == -1)
+ goto proxyfail;
+ ret += r2;
+
+ p = string_copy(hdr.v1.line);
+ end = memchr(p, '\r', ret - 1);
+
+ if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
{
DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
goto proxyfail;
}
*end = '\0'; /* Terminate the string */
- size = end + 2 - hdr.v1.line; /* Skip header + CRLF */
+ size = end + 2 - p; /* Skip header + CRLF */
DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
+ DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
/* Step through the string looking for the required fields. Ensure
- strict adherance to required formatting, exit for any error. */
+ strict adherence to required formatting, exit for any error. */
p += 5;
if (!isspace(*(p++)))
{
goto proxyfail;
}
*sp = '\0';
- if(!string_is_ip_address(p,NULL))
+ if(!string_is_ip_address(p, NULL))
{
DEBUG(D_receive)
debug_printf("Proxied src arg is not an %s address\n", iptype);
goto proxyfail;
}
*sp = '\0';
- if(!string_is_ip_address(p,NULL))
+ if(!string_is_ip_address(p, NULL))
{
DEBUG(D_receive)
debug_printf("Proxy dest arg is not an %s address\n", iptype);
goto proxyfail;
}
*sp = '\0';
- tmp_port = strtol(CCS p,&endc,10);
+ tmp_port = strtol(CCS p, &endc, 10);
if (*endc || tmp_port == 0)
{
DEBUG(D_receive)
DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
goto proxyfail;
}
- tmp_port = strtol(CCS p,&endc,10);
+ tmp_port = strtol(CCS p, &endc, 10);
if (*endc || tmp_port == 0)
{
DEBUG(D_receive)
}
proxy_external_port = tmp_port;
/* Already checked for /r /n above. Good V1 header received. */
- goto done;
}
else
{
/* Wrong protocol */
DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
+ (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
goto proxyfail;
}
+done:
+ DEBUG(D_receive)
+ debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
+ yield = proxy_session;
+
+/* Don't flush any potential buffer contents. Any input on proxyfail
+should cause a synchronization failure */
+
proxyfail:
-restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
-/* Don't flush any potential buffer contents. Any input should cause a
- synchronization failure */
-return FALSE;
+ restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
-done:
-restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
-DEBUG(D_receive)
- debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
-return proxy_session;
+bad:
+ if (yield)
+ {
+ sender_host_name = NULL;
+ (void) host_name_lookup();
+ host_build_sender_fullhost();
+ }
+ else
+ {
+ proxy_session_failed = TRUE;
+ DEBUG(D_receive)
+ debug_printf("Failure to extract proxied host, only QUIT allowed\n");
+ }
+
+return;
}
#endif
return when it runs.
Arguments:
- check_sync if TRUE, check synchronization rules if global option is TRUE
+ check_sync if TRUE, check synchronization rules if global option is TRUE
+ buffer_lim maximum to buffer in lower layer
Returns: a code identifying the command (enumerated above)
*/
static int
-smtp_read_command(BOOL check_sync)
+smtp_read_command(BOOL check_sync, unsigned buffer_lim)
{
int c;
int ptr = 0;
os_non_restarting_signal(SIGALRM, command_timeout_handler);
-while ((c = (receive_getc)()) != '\n' && c != EOF)
+while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
{
- if (ptr >= smtp_cmd_buffer_size)
+ if (ptr >= SMTP_CMD_BUFFER_SIZE)
{
os_non_restarting_signal(SIGALRM, sigalrm_handler);
return OTHER_CMD;
for (p = cmd_list; p < cmd_list_end; p++)
{
- #ifdef SUPPORT_PROXY
+#ifdef SUPPORT_PROXY
/* Only allow QUIT command if Proxy Protocol parsing failed */
- if (proxy_session && proxy_session_failed)
- {
- if (p->cmd != QUIT_CMD)
- continue;
- }
- #endif
+ if (proxy_session && proxy_session_failed && p->cmd != QUIT_CMD)
+ continue;
+#endif
if ( p->len
&& strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
&& ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
-/*************************************************
-* 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_in.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 *
*************************************************/
receive_swallow_smtp();
smtp_printf("421 %s\r\n", message);
-for (;;) switch(smtp_read_command(FALSE))
+for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
{
case EOF_CMD:
return;
uschar *
smtp_get_connection_info(void)
{
-uschar *hostname = (sender_fullhost == NULL)?
- sender_host_address : sender_fullhost;
+const uschar * hostname = sender_fullhost
+ ? sender_fullhost : sender_host_address;
if (host_checking)
return string_sprintf("SMTP connection from %s", hostname);
/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
the domain name of the sending host, or an ip literal in square brackets. The
-arrgument is placed in sender_helo_name, which is in malloc store, because it
+argument is placed in sender_helo_name, which is in malloc store, because it
must persist over multiple incoming messages. If helo_accept_junk is set, this
host is permitted to send any old junk (needed for some broken hosts).
Otherwise, helo_allow_chars can be used for rogue characters in general
uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
while (isspace(*v)) v--;
v[1] = 0;
-while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--;
+while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
+ {
+ /* Take care to not stop at a space embedded in a quoted local-part */
+
+ if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
+ v--;
+ }
n = v;
if (*v == '=')
static void
smtp_reset(void *reset_point)
{
-store_reset(reset_point);
recipients_list = NULL;
rcpt_count = rcpt_defer_count = rcpt_fail_count =
raw_recipients_count = recipients_count = recipients_list_max = 0;
-cancel_cutthrough_connection("smtp reset");
message_linecount = 0;
message_size = -1;
acl_added_headers = NULL;
suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
active_local_from_check = local_from_check; /* Can be set by ACL */
active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
-sender_address = NULL;
+sending_ip_address = NULL;
+return_path = sender_address = NULL;
+sender_data = NULL; /* Can be set by ACL */
+deliver_localpart_orig = NULL;
+deliver_domain_orig = NULL;
+callout_address = NULL;
submission_name = NULL; /* Can be set by ACL */
raw_sender = NULL; /* After SMTP rewrite, before qualifying */
sender_address_unrewritten = NULL; /* Set only after verify rewrite */
bmi_run = 0;
bmi_verdicts = NULL;
#endif
+dnslist_domain = dnslist_matched = NULL;
#ifndef DISABLE_DKIM
dkim_signers = NULL;
dkim_disable_verify = FALSE;
#endif
dsn_ret = 0;
dsn_envid = NULL;
+deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
#ifndef DISABLE_PRDR
prdr_requested = FALSE;
#endif
not the first message in an SMTP session and the previous message caused them
to be referenced in an ACL. */
-if (message_body != NULL)
+if (message_body)
{
store_free(message_body);
message_body = NULL;
}
-if (message_body_end != NULL)
+if (message_body_end)
{
store_free(message_body_end);
message_body_end = NULL;
repetition in the same message, but it seems right to repeat them for different
messages. */
-while (acl_warn_logged != NULL)
+while (acl_warn_logged)
{
string_item *this = acl_warn_logged;
acl_warn_logged = acl_warn_logged->next;
store_free(this);
}
+store_reset(reset_point);
}
if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
+cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
smtp_reset(reset_point); /* Reset for start of message */
/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
uschar *recipient = NULL;
int start, end, sender_domain, recipient_domain;
- switch(smtp_read_command(FALSE))
+ switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
{
/* The HELO/EHLO commands set sender_address_helo if they have
valid data; otherwise they are ignored, except that they do
/* Fall through */
case RSET_CMD:
+ cancel_cutthrough_connection(TRUE, US"RSET received");
smtp_reset(reset_point);
bsmtp_transaction_linecount = receive_linecount;
break;
/* Reset to start of message */
+ cancel_cutthrough_connection(TRUE, US"MAIL received");
smtp_reset(reset_point);
/* Apply SMTP rewrite */
+static BOOL
+smtp_log_tls_fail(uschar * errstr)
+{
+uschar * conn_info = smtp_get_connection_info();
+
+if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
+/* I'd like to get separated H= here, but too hard for now */
+
+log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
+return FALSE;
+}
+
+
/*************************************************
* Start an SMTP session *
*************************************************/
/* Allow for trailing 0 in the command and data buffers. */
-if (!(smtp_cmd_buffer = US malloc(2*smtp_cmd_buffer_size + 2)))
+if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
log_write(0, LOG_MAIN|LOG_PANIC_DIE,
"malloc() failed for SMTP command buffer");
smtp_cmd_buffer[0] = 0;
-smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1;
+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. */
/* Set up the buffer for inputting using direct read() calls, and arrange to
call the local functions instead of the standard C ones. */
-if (!(smtp_inbuffer = (uschar *)malloc(in_buffer_size)))
+if (!(smtp_inbuffer = (uschar *)malloc(IN_BUFFER_SIZE)))
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
receive_getc = smtp_getc;
"bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
}
- /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
- smtps port for use with older style SSL MTAs. */
-
- #ifdef SUPPORT_TLS
- if (tls_in.on_connect && tls_server_start(tls_require_ciphers) != OK)
- return FALSE;
- #endif
-
/* Test for explicit connection rejection */
if (verify_check_host(&host_reject_connection) == OK)
value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
not exist). */
- #ifdef USE_TCP_WRAPPERS
+#ifdef USE_TCP_WRAPPERS
errno = 0;
- tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name);
- if (tcp_wrappers_name == NULL)
- {
+ if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
"(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
expand_string_message);
- }
+
if (!hosts_ctl(tcp_wrappers_name,
- (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name,
- (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address,
- (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident))
+ sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
+ sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
+ sender_ident ? CS sender_ident : STRING_UNKNOWN))
{
if (errno == 0 || errno == ENOENT)
{
}
return FALSE;
}
- #endif
+#endif
/* Check for reserved slots. The value of smtp_accept_count has already been
incremented to include this process. */
if (smtp_batched_input) return TRUE;
-#ifdef SUPPORT_PROXY
/* If valid Proxy Protocol source is connecting, set up session.
* Failure will not allow any SMTP function other than QUIT. */
+
+#ifdef SUPPORT_PROXY
proxy_session = FALSE;
proxy_session_failed = FALSE;
if (check_proxy_protocol_host())
- if (!setup_proxy_protocol_host())
- {
- proxy_session_failed = TRUE;
- DEBUG(D_receive)
- debug_printf("Failure to extract proxied host, only QUIT allowed\n");
- }
- else
- {
- sender_host_name = NULL;
- (void)host_name_lookup();
- host_build_sender_fullhost();
- }
+ setup_proxy_protocol_host();
#endif
-/* Run the ACL if it exists */
+ /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
+ smtps port for use with older style SSL MTAs. */
+
+#ifdef SUPPORT_TLS
+ if (tls_in.on_connect && tls_server_start(tls_require_ciphers, &user_msg) != OK)
+ return smtp_log_tls_fail(user_msg);
+#endif
+
+/* Run the connect ACL if it exists */
user_msg = NULL;
if (acl_smtp_connect)
-/*************************************************
-* Log incomplete transactions *
-*************************************************/
-
-/* This function is called after a transaction has been aborted by RSET, QUIT,
-connection drops or other errors. It logs the envelope information received
-so far in order to preserve address verification attempts.
-
-Argument: string to indicate what aborted the transaction
-Returns: nothing
-*/
-
-static void
-incomplete_transaction_log(uschar *what)
-{
-if (sender_address == NULL || /* No transaction in progress */
- !LOGGING(smtp_incomplete_transaction))
- return;
-
-/* Build list of recipients for logging */
-
-if (recipients_count > 0)
- {
- int i;
- raw_recipients = store_get(recipients_count * sizeof(uschar *));
- for (i = 0; i < recipients_count; i++)
- raw_recipients[i] = recipients_list[i].address;
- raw_recipients_count = recipients_count;
- }
-
-log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
- "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
-}
-
-
-
-
/*************************************************
* Send SMTP response, possibly multiline *
*************************************************/
failures, but not defers. However, always log it for defer, and log it for fail
unless the sender_verify_fail log selector has been turned off. */
-if (sender_verified_failed != NULL &&
+if (sender_verified_failed &&
!testflag(sender_verified_failed, af_sverify_told))
{
BOOL save_rcpt_in_progress = rcpt_in_progress;
(sender_verified_failed->message == NULL)? US"" :
string_sprintf(": %s", sender_verified_failed->message));
- if (rc == FAIL && sender_verified_failed->user_message != NULL)
+ if (rc == FAIL && sender_verified_failed->user_message)
smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
testflag(sender_verified_failed, af_verify_pmfail)?
"Postmaster verification failed while checking <%s>\n%s\n"
passed to this function.
In case things go wrong while processing this function, causing an error that
-may re-enter this funtion, there is a recursion check.
+may re-enter this function, there is a recursion check.
Arguments:
reason What $smtp_notquit_reason will be set to in the ACL;
uschar *orcpt = NULL;
int flags;
-#if defined(SUPPORT_TLS) && defined(AUTH_TLS)
+#ifdef AUTH_TLS
/* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
if ( tls_in.active >= 0
&& tls_in.peercert
US &off, sizeof(off));
#endif
- switch(smtp_read_command(TRUE))
+ switch(smtp_read_command(TRUE, GETC_BUFFER_UNLIMITED))
{
/* The AUTH command is not permitted to occur inside a transaction, and may
occur successfully only once per connection. Actually, that isn't quite
dsn_advertised = TRUE;
}
- /* Advertise ETRN if there's an ACL checking whether a host is
- permitted to issue it; a check is made when any host actually tries. */
+ /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is
+ permitted to issue them; a check is made when any host actually tries. */
- if (acl_smtp_etrn != NULL)
+ if (acl_smtp_etrn)
{
s = string_catn(s, &size, &ptr, smtp_code, 3);
s = string_catn(s, &size, &ptr, US"-ETRN\r\n", 7);
}
-
- /* Advertise EXPN if there's an ACL checking whether a host is
- permitted to issue it; a check is made when any host actually tries. */
-
- if (acl_smtp_expn != NULL)
+ if (acl_smtp_vrfy)
+ {
+ s = string_catn(s, &size, &ptr, smtp_code, 3);
+ s = string_catn(s, &size, &ptr, US"-VRFY\r\n", 7);
+ }
+ if (acl_smtp_expn)
{
s = string_catn(s, &size, &ptr, smtp_code, 3);
s = string_catn(s, &size, &ptr, US"-EXPN\r\n", 7);
them in either case in the AUTH command. */
if ( auths
-#if defined(SUPPORT_TLS) && defined(AUTH_TLS)
+#ifdef AUTH_TLS
&& !sender_host_authenticated
#endif
&& verify_check_host(&auth_advertise_hosts) == OK
: pnormal)
+ (tls_in.active >= 0 ? pcrpted : 0)
];
+ cancel_cutthrough_connection(TRUE, US"sent EHLO response");
smtp_reset(reset_point);
toomany = FALSE;
break; /* HELO/EHLO */
/* Reset for start of message - even if this is going to fail, we
obviously need to throw away any previous data. */
+ cancel_cutthrough_connection(TRUE, US"MAIL received");
smtp_reset(reset_point);
toomany = FALSE;
sender_data = recipient_data = NULL;
case ENV_MAIL_OPT_UTF8:
if (smtputf8_advertised)
{
+ int old_pool = store_pool;
+
DEBUG(D_receive) debug_printf("smtputf8 requested\n");
message_smtputf8 = allow_utf8_domains = TRUE;
+ store_pool = POOL_PERM;
received_protocol = string_sprintf("utf8%s", received_protocol);
+ store_pool = old_pool;
}
break;
#endif
friends now makes it absolutely clear that it means *mailbox*. Consequently
we must always qualify this address, regardless. */
- if (recipient_domain == 0)
+ if (!recipient_domain)
if (!(recipient_domain = qualify_recipient(&recipient, smtp_cmd_data,
US"recipient")))
{
there may be a delay in this, re-check for a synchronization error
afterwards, unless pipelining was advertised. */
- 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())
+ if (recipients_discarded)
+ rc = DISCARD;
+ else
+ if ( (rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
+ &log_msg)) == OK
+ && !pipelining_advertised && !check_sync())
goto SYNC_FAILURE;
- }
/* The ACL was happy */
if (rc == OK)
{
- if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
- else smtp_user_msg(US"250", user_msg);
+ if (user_msg)
+ smtp_user_msg(US"250", user_msg);
+ else
+ smtp_printf("250 Accepted\r\n");
receive_add_recipient(recipient, -1);
/* Set the dsn flags in the recipients_list */
else if (rc == DISCARD)
{
- if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
- else smtp_user_msg(US"250", user_msg);
+ if (user_msg)
+ smtp_user_msg(US"250", user_msg);
+ else
+ smtp_printf("250 Accepted\r\n");
rcpt_fail_count++;
discarded = TRUE;
log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> RCPT %s: "
chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
? CHUNKING_LAST : CHUNKING_ACTIVE;
chunking_data_left = chunking_datasize;
+ DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
+ (int)chunking_state, chunking_data_left);
lwr_receive_getc = receive_getc;
lwr_receive_ungetc = receive_ungetc;
receive_getc = bdat_getc;
receive_ungetc = bdat_ungetc;
- DEBUG(D_any)
- debug_printf("chunking state %d\n", (int)chunking_state);
goto DATA_BDAT;
}
}
if (chunking_state > CHUNKING_OFFERED)
- { /* No predata ACL or go-ahead output for BDAT */
- rc = OK;
- }
+ rc = OK; /* No predata ACL or go-ahead output for BDAT */
else
{
/* If there is an ACL, re-check the synchronization afterwards, since the
break;
}
- if (recipient_domain == 0)
+ if (!recipient_domain)
if (!(recipient_domain = qualify_recipient(&address, smtp_cmd_data,
US"verify")))
break;
/* RFC 2487 is not clear on when this command may be sent, though it
does state that all information previously obtained from the client
- must be discarded if a TLS session is started. It seems reasonble to
+ must be discarded if a TLS session is started. It seems reasonable to
do an implied RSET when STARTTLS is received. */
incomplete_transaction_log(US"STARTTLS");
+ cancel_cutthrough_connection(TRUE, US"STARTTLS received");
smtp_reset(reset_point);
toomany = FALSE;
cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE;
/* and if TLS is already active, tls_server_start() should fail */
}
- /* There is nothing we value in the input buffer and if TLS is succesfully
+ /* There is nothing we value in the input buffer and if TLS is successfully
negotiated, we won't use this buffer again; if TLS fails, we'll just read
fresh content into it. The buffer contains arbitrary content from an
untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
It seems safest to just wipe away the content rather than leave it as a
target to jump to. */
- memset(smtp_inbuffer, 0, in_buffer_size);
+ memset(smtp_inbuffer, 0, IN_BUFFER_SIZE);
/* Attempt to start up a TLS session, and if successful, discard all
knowledge that was obtained previously. At least, that's what the RFC says,
We must allow for an extra EHLO command and an extra AUTH command after
STARTTLS that don't add to the nonmail command count. */
- if ((rc = tls_server_start(tls_require_ciphers)) == OK)
+ s = NULL;
+ if ((rc = tls_server_start(tls_require_ciphers, &s)) == OK)
{
if (!tls_remember_esmtp)
helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE;
DEBUG(D_tls) debug_printf("TLS active\n");
break; /* Successful STARTTLS */
}
+ else
+ (void) smtp_log_tls_fail(s);
/* Some local configuration problem was discovered before actually trying
to do a TLS handshake; give a temporary error. */
- else if (rc == DEFER)
+ if (rc == DEFER)
{
smtp_printf("454 TLS currently unavailable\r\n");
break;
set, but we must still reject all incoming commands. */
DEBUG(D_tls) debug_printf("TLS failed to start\n");
- while (done <= 0) switch(smtp_read_command(FALSE))
+ while (done <= 0) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
{
case EOF_CMD:
log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF",
case RSET_CMD:
smtp_rset_handler();
+ cancel_cutthrough_connection(TRUE, US"RSET received");
smtp_reset(reset_point);
toomany = FALSE;
break;
case BADSYN_CMD:
SYNC_FAILURE:
- if (smtp_inend >= smtp_inbuffer + in_buffer_size)
- smtp_inend = smtp_inbuffer + in_buffer_size - 1;
+ if (smtp_inend >= smtp_inbuffer + IN_BUFFER_SIZE)
+ smtp_inend = smtp_inbuffer + IN_BUFFER_SIZE - 1;
c = smtp_inend - smtp_inptr;
if (c > 150) c = 150;
smtp_inptr[c] = 0;
git://git.exim.org / exim.git / blobdiff