bundled_pjproject: Improve SSL/TLS error handling

OpenSSL has 2 levels or error processing.  It's possible for the
top layer to return SSL_ERROR_SYSCALL but the lower layer return
no error, in which case processing should continue.  Only the top
layer was being examined though so connections were being torn
down when they didn't need to be.  This patch adds the examination
of the lower level codes, and if they return no errors, allows
processing to continue.

ASTERISK-27001
Reported-by: Ian Gilmour
patches:
	pjproject-2.6.patch submitted by Ian Gilmour (license 6889)

Updated-by: George Joseph and Sauw Ming (Teluu)

Merged to upstream pjproject on 7/27/2017 (commit 5631)

Change-Id: I23844ca0c68ef1ee550f14d46f6dae57d33b7bd2

third-party/pjproject/patches/0075-Fixed-2030-Improve-error-handling-in-OpenSSL-socket.patch

+From 96c06899d95eaf01d05561554b21e8c63baa7129 Mon Sep 17 00:00:00 2001
+From: ming <ming@localhost>
+Date: Thu, 27 Jul 2017 06:07:54 +0000
+Subject: [PATCH 75/76] Fixed #2030: Improve error handling in OpenSSL socket
+
+---
+ pjlib/src/pj/ssl_sock_ossl.c | 173 ++++++++++++++++++++++++++++++++++++++-----
+ 1 file changed, 156 insertions(+), 17 deletions(-)
+
+diff --git a/pjlib/src/pj/ssl_sock_ossl.c b/pjlib/src/pj/ssl_sock_ossl.c
+index c466b3c..b8175e1 100644
+--- a/pjlib/src/pj/ssl_sock_ossl.c
++++ b/pjlib/src/pj/ssl_sock_ossl.c
+@@ -298,14 +298,104 @@ static pj_status_t flush_delayed_send(pj_ssl_sock_t *ssock);
+ /* Expected maximum value of reason component in OpenSSL error code */
+ #define MAX_OSSL_ERR_REASON		1200
+ 
+-static pj_status_t STATUS_FROM_SSL_ERR(pj_ssl_sock_t *ssock,
+-				       unsigned long err)
++
++static char *SSLErrorString (int err)
+ {
+-    pj_status_t status;
++    switch (err) {
++    case SSL_ERROR_NONE:
++	return "SSL_ERROR_NONE";
++    case SSL_ERROR_ZERO_RETURN:
++	return "SSL_ERROR_ZERO_RETURN";
++    case SSL_ERROR_WANT_READ:
++	return "SSL_ERROR_WANT_READ";
++    case SSL_ERROR_WANT_WRITE:
++	return "SSL_ERROR_WANT_WRITE";
++    case SSL_ERROR_WANT_CONNECT:
++	return "SSL_ERROR_WANT_CONNECT";
++    case SSL_ERROR_WANT_ACCEPT:
++	return "SSL_ERROR_WANT_ACCEPT";
++    case SSL_ERROR_WANT_X509_LOOKUP:
++	return "SSL_ERROR_WANT_X509_LOOKUP";
++    case SSL_ERROR_SYSCALL:
++	return "SSL_ERROR_SYSCALL";
++    case SSL_ERROR_SSL:
++	return "SSL_ERROR_SSL";
++    default:
++	return "SSL_ERROR_UNKNOWN";
++    }
++}
+ 
+-    /* General SSL error, dig more from OpenSSL error queue */
+-    if (err == SSL_ERROR_SSL)
+-	err = ERR_get_error();
++#define ERROR_LOG(msg, err) \
++    PJ_LOG(2,("SSL", "%s (%s): Level: %d err: <%lu> <%s-%s-%s> len: %d", \
++	      msg, action, level, err, \
++	      (ERR_lib_error_string(err)? ERR_lib_error_string(err): "???"), \
++	      (ERR_func_error_string(err)? ERR_func_error_string(err):"???"),\
++	      (ERR_reason_error_string(err)? \
++	       ERR_reason_error_string(err): "???"), len));
++
++static void SSLLogErrors(char * action, int ret, int ssl_err, int len)
++{
++    char *ssl_err_str = SSLErrorString(ssl_err);
++
++    if (!action) {
++	action = "UNKNOWN";
++    }
++
++    switch (ssl_err) {
++    case SSL_ERROR_SYSCALL:
++    {
++	unsigned long err2 = ERR_get_error();
++	if (err2) {
++	    int level = 0;
++	    while (err2) {
++	        ERROR_LOG("SSL_ERROR_SYSCALL", err2);
++		level++;
++		err2 = ERR_get_error();
++	    }
++	} else if (ret == 0) {
++	    /* An EOF was observed that violates the protocol */
++
++	    /* The TLS/SSL handshake was not successful but was shut down
++	     * controlled and by the specifications of the TLS/SSL protocol.
++	     */
++	} else if (ret == -1) {
++	    /* BIO error - look for more info in errno... */
++	    char errStr[250] = "";
++	    strerror_r(errno, errStr, sizeof(errStr));
++	    /* for now - continue logging these if they occur.... */
++	    PJ_LOG(4,("SSL", "BIO error, SSL_ERROR_SYSCALL (%s): "
++	    		     "errno: <%d> <%s> len: %d",
++		      	     action, errno, errStr, len));
++	} else {
++	    /* ret!=0 & ret!=-1 & nothing on error stack - is this valid??? */
++	    PJ_LOG(2,("SSL", "SSL_ERROR_SYSCALL (%s) ret: %d len: %d",
++		      action, ret, len));
++	}
++	break;
++    }
++    case SSL_ERROR_SSL:
++    {
++	unsigned long err2 = ERR_get_error();
++	int level = 0;
++
++	while (err2) {
++	    ERROR_LOG("SSL_ERROR_SSL", err2);
++	    level++;
++	    err2 = ERR_get_error();
++	}
++	break;
++    }
++    default:
++	PJ_LOG(2,("SSL", "%lu [%s] (%s) ret: %d len: %d",
++		  ssl_err, ssl_err_str, action, ret, len));
++	break;
++    }
++}
++
++
++static pj_status_t GET_STATUS_FROM_SSL_ERR(unsigned long err)
++{
++    pj_status_t status;
+ 
+     /* OpenSSL error range is much wider than PJLIB errno space, so
+      * if it exceeds the space, only the error reason will be kept.
+@@ -317,13 +407,49 @@ static pj_status_t STATUS_FROM_SSL_ERR(pj_ssl_sock_t *ssock,
+ 	status = ERR_GET_REASON(err);
+ 
+     status += PJ_SSL_ERRNO_START;
+-    ssock->last_err = err;
+     return status;
+ }
+ 
++/* err contains ERR_get_error() status */
++static pj_status_t STATUS_FROM_SSL_ERR(char *action, pj_ssl_sock_t *ssock,
++				       unsigned long err)
++{
++    int level = 0;
++    int len = 0; //dummy
++
++    ERROR_LOG("STATUS_FROM_SSL_ERR", err);
++    level++;
++
++    /* General SSL error, dig more from OpenSSL error queue */
++    if (err == SSL_ERROR_SSL) {
++	err = ERR_get_error();
++	ERROR_LOG("STATUS_FROM_SSL_ERR", err);
++    }
++
++    ssock->last_err = err;
++    return GET_STATUS_FROM_SSL_ERR(err);
++}
++
++/* err contains SSL_get_error() status */
++static pj_status_t STATUS_FROM_SSL_ERR2(char *action, pj_ssl_sock_t *ssock,
++					int ret, int err, int len)
++{
++    unsigned long ssl_err = err;
++
++    if (err == SSL_ERROR_SSL) {
++	ssl_err = ERR_peek_error();
++    }
++
++    /* Dig for more from OpenSSL error queue */
++    SSLLogErrors(action, ret, err, len);
++
++    ssock->last_err = ssl_err;
++    return GET_STATUS_FROM_SSL_ERR(ssl_err);
++}
++
+ static pj_status_t GET_SSL_STATUS(pj_ssl_sock_t *ssock)
+ {
+-    return STATUS_FROM_SSL_ERR(ssock, ERR_get_error());
++    return STATUS_FROM_SSL_ERR("status", ssock, ERR_get_error());
+ }
+ 
+ 
+@@ -1514,7 +1640,7 @@ static pj_bool_t on_handshake_complete(pj_ssl_sock_t *ssock,
+ 		unsigned long err;
+ 		err = ERR_get_error();
+ 		if (err != SSL_ERROR_NONE)
+-		    status = STATUS_FROM_SSL_ERR(ssock, err);
++		    status = STATUS_FROM_SSL_ERR("connecting", ssock, err);
+ 	    }
+ 	    reset_ssl_sock_state(ssock);
+ 	}
+@@ -1833,11 +1959,11 @@ static pj_status_t do_handshake(pj_ssl_sock_t *ssock)
+     }
+ 
+     if (err < 0) {
+-	err = SSL_get_error(ssock->ossl_ssl, err);
+-	if (err != SSL_ERROR_NONE && err != SSL_ERROR_WANT_READ) 
++	int err2 = SSL_get_error(ssock->ossl_ssl, err);
++	if (err2 != SSL_ERROR_NONE && err2 != SSL_ERROR_WANT_READ)
+ 	{
+ 	    /* Handshake fails */
+-	    status = STATUS_FROM_SSL_ERR(ssock, err);
++	    status = STATUS_FROM_SSL_ERR2("Handshake", ssock, err, err2, 0);
+ 	    return status;
+ 	}
+     }
+@@ -1913,6 +2039,7 @@ static pj_bool_t asock_on_data_read (pj_activesock_t *asock,
+ 	    read_data_t *buf = *(OFFSET_OF_READ_DATA_PTR(ssock, data));
+ 	    void *data_ = (pj_int8_t*)buf->data + buf->len;
+ 	    int size_ = (int)(ssock->read_size - buf->len);
++	    int len = size_;
+ 
+ 	    /* SSL_read() may write some data to BIO write when re-negotiation
+ 	     * is on progress, so let's protect it with write mutex.
+@@ -1965,10 +2092,22 @@ static pj_bool_t asock_on_data_read (pj_activesock_t *asock,
+ 		 */
+ 		if (err != SSL_ERROR_NONE && err != SSL_ERROR_WANT_READ)
+ 		{
+-		    /* Reset SSL socket state, then return PJ_FALSE */
+-		    status = STATUS_FROM_SSL_ERR(ssock, err);
+-		    reset_ssl_sock_state(ssock);
+-		    goto on_error;
++		    if (err == SSL_ERROR_SYSCALL && size_ == -1 &&
++			ERR_peek_error() == 0 && errno == 0)
++		    {
++			status = STATUS_FROM_SSL_ERR2("Read", ssock, size_,
++						      err, len);
++			PJ_LOG(4,("SSL", "SSL_read() = -1, with "
++				  	 "SSL_ERROR_SYSCALL, no SSL error, "
++				  	 "and errno = 0 - skip BIO error"));
++		        /* Ignore these errors */
++		    } else {
++		        /* Reset SSL socket state, then return PJ_FALSE */
++		        status = STATUS_FROM_SSL_ERR2("Read", ssock, size_,
++		        			      err, len);
++		        reset_ssl_sock_state(ssock);
++		        goto on_error;
++		    }
+ 		}
+ 
+ 		status = do_handshake(ssock);
+@@ -2856,7 +2995,7 @@ static pj_status_t ssl_write(pj_ssl_sock_t *ssock,
+ 		status = PJ_EBUSY;
+ 	} else {
+ 	    /* Some problem occured */
+-	    status = STATUS_FROM_SSL_ERR(ssock, err);
++	    status = STATUS_FROM_SSL_ERR2("Write", ssock, nwritten, err, size);
+ 	}
+     } else {
+ 	/* nwritten < *size, shouldn't happen, unless write BIO cannot hold 
+-- 
+2.9.4
+