diff options
| -rw-r--r-- | src/src/functions.h | 3 | ||||
| -rw-r--r-- | src/src/globals.c | 1 | ||||
| -rw-r--r-- | src/src/globals.h | 1 | ||||
| -rw-r--r-- | src/src/receive.c | 10 | ||||
| -rw-r--r-- | src/src/smtp_in.c | 401 | ||||
| -rw-r--r-- | src/src/tls-gnu.c | 4 | ||||
| -rw-r--r-- | src/src/tls-openssl.c | 4 | ||||
| -rw-r--r-- | src/src/transports/smtp.c | 1 |
8 files changed, 213 insertions, 212 deletions
diff --git a/src/src/functions.h b/src/src/functions.h index 0cf80dfbb..ba02b82b2 100644 --- a/src/src/functions.h +++ b/src/src/functions.h @@ -56,7 +56,7 @@ extern BOOL tls_client_start(client_conn_ctx *, smtp_connect_args *, extern void tls_client_creds_reload(BOOL); extern void tls_close(void *, int); -extern BOOL tls_could_read(void); +extern BOOL tls_could_getc(void); extern void tls_daemon_init(void); extern int tls_daemon_tick(void); extern BOOL tls_dropprivs_validate_require_cipher(BOOL); @@ -478,7 +478,6 @@ extern void sha1_start(hctx *); extern int sieve_interpret(uschar *, int, uschar *, uschar *, uschar *, uschar *, address_item **, uschar **); extern void sigalrm_handler(int); -extern BOOL smtp_buffered(void); extern void smtp_closedown(uschar *); extern void smtp_command_timeout_exit(void) NORETURN; extern void smtp_command_sigterm_exit(void) NORETURN; diff --git a/src/src/globals.c b/src/src/globals.c index 98e0f8daf..0109cd711 100644 --- a/src/src/globals.c +++ b/src/src/globals.c @@ -183,7 +183,6 @@ BOOL (*receive_hasc)(void) = stdin_hasc; int (*receive_ungetc)(int) = stdin_ungetc; int (*receive_feof)(void) = stdin_feof; int (*receive_ferror)(void) = stdin_ferror; -BOOL (*receive_smtp_buffered)(void) = NULL; /* Only used for SMTP */ #endif diff --git a/src/src/globals.h b/src/src/globals.h index fbc9c76ee..5bd936452 100644 --- a/src/src/globals.h +++ b/src/src/globals.h @@ -171,7 +171,6 @@ extern void (*receive_get_cache)(unsigned); extern int (*receive_ungetc)(int); extern int (*receive_feof)(void); extern int (*receive_ferror)(void); -extern BOOL (*receive_smtp_buffered)(void); /* For clearing, saving, restoring address expansion variables. We have to have diff --git a/src/src/receive.c b/src/src/receive.c index 3adcbbd88..f4b829659 100644 --- a/src/src/receive.c +++ b/src/src/receive.c @@ -4212,7 +4212,7 @@ f.receive_call_bombout = TRUE; /* Before sending an SMTP response in a TCP/IP session, we check to see if the connection has gone away. This can only be done if there is no unconsumed input waiting in the local input buffer. We can test for this by calling -receive_smtp_buffered(). RFC 2920 (pipelining) explicitly allows for additional +receive_hasc(). RFC 2920 (pipelining) explicitly allows for additional input to be sent following the final dot, so the presence of following input is not an error. @@ -4227,8 +4227,8 @@ Of course, since TCP/IP is asynchronous, there is always a chance that the connection will vanish between the time of this test and the sending of the response, but the chance of this happening should be small. */ -if (smtp_input && sender_host_address && !f.sender_host_notsocket && - !receive_smtp_buffered()) +if ( smtp_input && sender_host_address && !f.sender_host_notsocket + && !receive_hasc()) { if (poll_one_fd(fileno(smtp_in), POLLIN, 0) != 0) { @@ -4409,12 +4409,12 @@ if (smtp_input) the socket. */ smtp_printf("250- %u byte chunk, total %d\r\n250 OK id=%s\r\n", - receive_smtp_buffered(), + receive_hasc(), chunking_datasize, message_size+message_linecount, message_id); chunking_state = CHUNKING_OFFERED; } else - smtp_printf("250 OK id=%s\r\n", receive_smtp_buffered(), message_id); + smtp_printf("250 OK id=%s\r\n", receive_hasc(), message_id); if (host_checking) fprintf(stdout, diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c index 7cb966f24..5de861216 100644 --- a/src/src/smtp_in.c +++ b/src/src/smtp_in.c @@ -320,92 +320,6 @@ 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. 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 -wouldblock_reading(void) -{ -int fd, rc; - -#ifndef DISABLE_TLS -if (tls_in.active.sock >= 0) - return !tls_could_read(); -#endif - -if (smtp_inptr < smtp_inend) - return FALSE; - -fd = fileno(smtp_in); -rc = poll_one_fd(fd, POLLIN, 0); - -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); -return FALSE; -} - -static BOOL -check_sync(void) -{ -if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket) - return TRUE; - -return wouldblock_reading(); -} - - -/* If there's input waiting (and we're doing pipelineing) then we can pipeline -a reponse with the one following. */ - -static BOOL -pipeline_response(void) -{ -if ( !smtp_enforce_sync || !sender_host_address - || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised) - return FALSE; - -if (wouldblock_reading()) return FALSE; -f.smtp_in_pipelining_used = TRUE; -return TRUE; -} - - -#ifndef DISABLE_PIPE_CONNECT -static BOOL -pipeline_connect_sends(void) -{ -if (!sender_host_address || f.sender_host_notsocket || !fl.pipe_connect_acceptable) - return FALSE; - -if (wouldblock_reading()) return FALSE; -f.smtp_in_early_pipe_used = TRUE; -return TRUE; -} -#endif - -/************************************************* * Log incomplete transactions * *************************************************/ @@ -487,6 +401,25 @@ receive_bomb_out(US"signal-exit", } +/******************************************************************************/ +/* SMTP input buffer handling. Most of these are similar to stdio routines. */ + +static void +smtp_buf_init(void) +{ +/* Set up the buffer for inputting using direct read() calls, and arrange to +call the local functions instead of the standard C ones. Place a NUL at the +end of the buffer to safety-stop C-string reads from it. */ + +if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE))) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); +smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0'; + +smtp_inptr = smtp_inend = smtp_inbuffer; +smtp_had_eof = smtp_had_error = 0; +} + + /* Refill the buffer, and notify DKIM verification code. Return false for error or EOF. @@ -496,6 +429,7 @@ static BOOL smtp_refill(unsigned lim) { int rc, save_errno; + if (!smtp_out) return FALSE; fflush(smtp_out); if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); @@ -537,11 +471,18 @@ smtp_inptr = smtp_inbuffer; return TRUE; } -/************************************************* -* SMTP version of getc() * -*************************************************/ -/* This gets the next byte from the SMTP input buffer. If the buffer is empty, +/* Check if there is buffered data */ + +BOOL +smtp_hasc(void) +{ +return smtp_inptr < smtp_inend; +} + +/* 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 negotiated itself into an TLS/SSL state. @@ -553,17 +494,11 @@ Returns: the next character or EOF int smtp_getc(unsigned lim) { -if (smtp_inptr >= smtp_inend) - if (!smtp_refill(lim)) - return EOF; +if (!smtp_hasc() && !smtp_refill(lim)) return EOF; return *smtp_inptr++; } -BOOL -smtp_hasc(void) -{ -return smtp_inptr < smtp_inend; -} +/* Get many bytes, refilling buffer if needed */ uschar * smtp_getbuf(unsigned * len) @@ -571,9 +506,8 @@ smtp_getbuf(unsigned * len) unsigned size; uschar * buf; -if (smtp_inptr >= smtp_inend) - if (!smtp_refill(*len)) - { *len = 0; return NULL; } +if (!smtp_hasc() && !smtp_refill(*len)) + { *len = 0; return NULL; } if ((size = smtp_inend - smtp_inptr) > *len) size = *len; buf = smtp_inptr; @@ -582,6 +516,9 @@ smtp_inptr += size; return buf; } +/* Copy buffered data to the dkim feed. +Called, unless TLS, just before starting to read message headers. */ + void smtp_get_cache(unsigned lim) { @@ -595,6 +532,130 @@ if (n > 0) } +/* SMTP version of ungetc() +Puts a character back in the input buffer. Only ever called once. + +Arguments: + ch the character + +Returns: the character +*/ + +int +smtp_ungetc(int ch) +{ +if (smtp_inptr <= smtp_inbuffer) /* NB: NOT smtp_hasc() ! */ + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "buffer underflow in smtp_ungetc"); + +*--smtp_inptr = ch; +return ch; +} + + +/* SMTP version of feof() +Tests for a previous EOF + +Arguments: none +Returns: non-zero if the eof flag is set +*/ + +int +smtp_feof(void) +{ +return smtp_had_eof; +} + + +/* SMTP version of ferror() +Tests for a previous read error, and returns with errno +restored to what it was when the error was detected. + +Arguments: none +Returns: non-zero if the error flag is set +*/ + +int +smtp_ferror(void) +{ +errno = smtp_had_error; +return smtp_had_error; +} + + +/* Check if a getc will block or not */ + +static BOOL +smtp_could_getc(void) +{ +int fd, rc; +fd_set fds; +struct timeval tzero = {.tv_sec = 0, .tv_usec = 0}; + +if (smtp_inptr < smtp_inend) + return TRUE; + +fd = fileno(smtp_in); +FD_ZERO(&fds); +FD_SET(fd, &fds); +rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); + +if (rc <= 0) return FALSE; /* Not ready to read */ +rc = smtp_getc(GETC_BUFFER_UNLIMITED); +if (rc < 0) return FALSE; /* End of file or error */ + +smtp_ungetc(rc); +return TRUE; +} + + +/******************************************************************************/ +/************************************************* +* Recheck synchronization * +*************************************************/ + +/* Synchronization checks can never be perfect because a packet may be on its +way but not arrived when the check is done. 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 +wouldblock_reading(void) +{ +#ifndef DISABLE_TLS +if (tls_in.active.sock >= 0) + return !tls_could_getc(); +#endif + +return !smtp_could_getc(); +} + +static BOOL +check_sync(void) +{ +if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket) + return TRUE; + +return wouldblock_reading(); +} + + +/******************************************************************************/ +/* Variants of the smtp_* input handling functions for use in CHUNKING mode */ + /* Forward declarations */ static inline void bdat_push_receive_functions(void); static inline void bdat_pop_receive_functions(void); @@ -831,30 +892,6 @@ lwr_receive_hasc = NULL; lwr_receive_ungetc = NULL; } -/************************************************* -* SMTP version of ungetc() * -*************************************************/ - -/* Puts a character back in the input buffer. Only ever -called once. - -Arguments: - ch the character - -Returns: the character -*/ - -int -smtp_ungetc(int ch) -{ -if (smtp_inptr <= smtp_inbuffer) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "buffer underflow in smtp_ungetc"); - -*--smtp_inptr = ch; -return ch; -} - - int bdat_ungetc(int ch) { @@ -865,62 +902,7 @@ return lwr_receive_ungetc(ch); -/************************************************* -* SMTP version of feof() * -*************************************************/ - -/* Tests for a previous EOF - -Arguments: none -Returns: non-zero if the eof flag is set -*/ - -int -smtp_feof(void) -{ -return smtp_had_eof; -} - - - - -/************************************************* -* SMTP version of ferror() * -*************************************************/ - -/* Tests for a previous read error, and returns with errno -restored to what it was when the error was detected. - -Arguments: none -Returns: non-zero if the error flag is set -*/ - -int -smtp_ferror(void) -{ -errno = smtp_had_error; -return smtp_had_error; -} - - - -/************************************************* -* Test for characters in the SMTP buffer * -*************************************************/ - -/* Used at the end of a message - -Arguments: none -Returns: TRUE/FALSE -*/ - -BOOL -smtp_buffered(void) -{ -return smtp_inptr < smtp_inend; -} - - +/******************************************************************************/ /************************************************* * Write formatted string to SMTP channel * @@ -1050,6 +1032,35 @@ return smtp_write_error; +/* If there's input waiting (and we're doing pipelineing) then we can pipeline +a reponse with the one following. */ + +static BOOL +pipeline_response(void) +{ +if ( !smtp_enforce_sync || !sender_host_address + || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised) + return FALSE; + +if (wouldblock_reading()) return FALSE; +f.smtp_in_pipelining_used = TRUE; +return TRUE; +} + + +#ifndef DISABLE_PIPE_CONNECT +static BOOL +pipeline_connect_sends(void) +{ +if (!sender_host_address || f.sender_host_notsocket || !fl.pipe_connect_acceptable) + return FALSE; + +if (wouldblock_reading()) return FALSE; +f.smtp_in_early_pipe_used = TRUE; +return TRUE; +} +#endif + /************************************************* * SMTP command read timeout * *************************************************/ @@ -1671,12 +1682,13 @@ for (smtp_cmd_list * p = cmd_list; p < cmd_list_end; p++) || smtp_cmd_buffer[p->len] == ' ' ) ) { - if (smtp_inptr < smtp_inend && /* Outstanding input */ - p->cmd < sync_cmd_limit && /* Command should sync */ - check_sync && /* Local flag set */ - smtp_enforce_sync && /* Global flag set */ - sender_host_address != NULL && /* Not local input */ - !f.sender_host_notsocket) /* Really is a socket */ + if ( smtp_inptr < smtp_inend /* Outstanding input */ + && p->cmd < sync_cmd_limit /* Command should sync */ + && check_sync /* Local flag set */ + && smtp_enforce_sync /* Global flag set */ + && sender_host_address != NULL /* Not local input */ + && !f.sender_host_notsocket /* Really is a socket */ + ) return BADSYN_CMD; /* The variables $smtp_command and $smtp_command_argument point into the @@ -1725,7 +1737,8 @@ if ( smtp_inptr < smtp_inend /* Outstanding input */ && check_sync /* Local flag set */ && smtp_enforce_sync /* Global flag set */ && sender_host_address /* Not local input */ - && !f.sender_host_notsocket) /* Really is a socket */ + && !f.sender_host_notsocket /* Really is a socket */ + ) return BADSYN_CMD; return OTHER_CMD; @@ -2580,12 +2593,9 @@ else (sender_host_address ? protocols : protocols_local) [pnormal]; /* Set up the buffer for inputting using direct read() calls, and arrange to -call the local functions instead of the standard C ones. Place a NUL at the -end of the buffer to safety-stop C-string reads from it. */ +call the local functions instead of the standard C ones. */ -if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE))) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); -smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0'; +smtp_buf_init(); receive_getc = smtp_getc; receive_getbuf = smtp_getbuf; @@ -2594,13 +2604,10 @@ receive_hasc = smtp_hasc; receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; -receive_smtp_buffered = smtp_buffered; lwr_receive_getc = NULL; lwr_receive_getbuf = NULL; lwr_receive_hasc = NULL; lwr_receive_ungetc = NULL; -smtp_inptr = smtp_inend = smtp_inbuffer; -smtp_had_eof = smtp_had_error = 0; /* Set up the message size limit; this may be host-specific */ @@ -5586,7 +5593,7 @@ while (done <= 0) Pipelining sync checks will normally have protected us too, unless disabled by configuration. */ - if (receive_smtp_buffered()) + if (receive_hasc()) { DEBUG(D_any) debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n"); diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 7b67bb793..c5a9ad096 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -3138,7 +3138,6 @@ receive_hasc = tls_hasc; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; -receive_smtp_buffered = tls_smtp_buffered; return OK; } @@ -3741,7 +3740,6 @@ if (!ct_ctx) /* server */ receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; - receive_smtp_buffered = smtp_buffered; } gnutls_deinit(state->session); @@ -3899,7 +3897,7 @@ if (n > 0) BOOL -tls_could_read(void) +tls_could_getc(void) { return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm || gnutls_record_check_pending(state_server.session) > 0; diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c index 51eeedc5b..830978e04 100644 --- a/src/src/tls-openssl.c +++ b/src/src/tls-openssl.c @@ -3351,7 +3351,6 @@ receive_hasc = tls_hasc; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; -receive_smtp_buffered = tls_smtp_buffered; tls_in.active.sock = fileno(smtp_out); tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */ @@ -4168,7 +4167,7 @@ if (n > 0) BOOL -tls_could_read(void) +tls_could_getc(void) { return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm || SSL_pending(state_server.lib_state.lib_ssl) > 0; @@ -4423,7 +4422,6 @@ if (!o_ctx) /* server side */ receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; - receive_smtp_buffered = smtp_buffered; tls_in.active.tls_ctx = NULL; tls_in.sni = NULL; /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */ diff --git a/src/src/transports/smtp.c b/src/src/transports/smtp.c index c64bb7010..ee07bcfe8 100644 --- a/src/src/transports/smtp.c +++ b/src/src/transports/smtp.c @@ -4349,6 +4349,7 @@ else "%s: %s", sx->buffer, strerror(errno)); } else if (addr->transport_return == DEFER) + /*XXX magic value -2 ? maybe host+message ? */ retry_add_item(addr, addr->address_retry_key, -2); } #endif |