diff options
| -rw-r--r-- | common/smtppass.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/common/smtppass.c b/common/smtppass.c index 984744d..a0e59cf 100644 --- a/common/smtppass.c +++ b/common/smtppass.c @@ -91,6 +91,7 @@ clamsmtp_thread_t; #define SMTP_DATA "DATA" CRLF #define SMTP_BANNER "220 clamsmtp" CRLF +#define SMTP_HELO_RSP "250 clamsmtp" CRLF #define SMTP_DELIMS "\r\n\t :-" #define ESMTP_PIPELINE "PIPELINING" @@ -674,11 +675,13 @@ static int smtp_passthru(clamsmtp_context_t* ctx) { char logline[LINE_LENGTH]; int r, ret = 0; - int first_rsp = 1; - int filter_ehlo = 0; fd_set mask; int neterror = 0; + int first_rsp = 1; /* The first 220 response from server to be filtered */ + int filter_ehlo = 0; /* Filtering parts of an EHLO extensions response */ + int filter_host = 0; /* Next response is 250 hostname, which we change */ + ASSERT(ctx->clam != -1 && ctx->server != -1); logline[0] = 0; @@ -720,9 +723,9 @@ static int smtp_passthru(clamsmtp_context_t* ctx) continue; } - /* Only valid after an EHLO command */ - if(filter_ehlo) - filter_ehlo = 0; + /* Only valid after EHLO or HELO commands */ + filter_ehlo = 0; + filter_host = 0; /* Handle the DATA section via our AV checker */ if(is_first_word(ctx->line, DATA_CMD, KL(DATA_CMD))) @@ -757,6 +760,7 @@ static int smtp_passthru(clamsmtp_context_t* ctx) { messagex(ctx, LOG_DEBUG, "filtering EHLO response"); filter_ehlo = 1; + filter_host = 1; /* A new message */ logline[0] = 0; @@ -768,6 +772,8 @@ static int smtp_passthru(clamsmtp_context_t* ctx) */ else if(is_first_word(ctx->line, HELO_CMD, KL(HELO_CMD))) { + filter_host = 1; + /* A new message line */ logline[0] = 0; } @@ -849,6 +855,26 @@ static int smtp_passthru(clamsmtp_context_t* ctx) } /* + * Certain mail servers (Postfix 1.x in particular) do a loop check + * on the 250 response after a EHLO or HELO. This is where we + * filter that to prevent loopback errors. + */ + if(filter_host) + { + filter_host = 0; + + if(check_first_word(ctx->line, OK_RSP, KL(OK_RSP), SMTP_DELIMS) > 0) + { + messagex(ctx, LOG_DEBUG, "intercepting host response"); + + if(write_data(ctx, &(ctx->client), SMTP_HELO_RSP) == -1) + RETURN(-1); + + continue; + } + } + + /* * Filter out any EHLO responses that we can't or don't want * to support. For example pipelining or TLS. */ |