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FTP: when EPSV gets a 229 but fails to connect, retry with PASV

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This is a regression as this logic used to work. It isn't clear when it
broke, but I'm assuming in 7.28.0 when we went all-multi internally.

This likely never worked with the multi interface. As the failed
connection is detected once the multi state has reached DO_MORE, the
Curl_do_more() function was now expanded somewhat so that the
ftp_do_more() function can request to go "back" to the previous state
when it makes another attempt - using PASV.

Added test case 1233 to verify this fix. It has the little issue that it
assumes no service is listening/accepting connections on port 1...

Reported-by: byte_bucket in the #curl IRC channel
This commit is contained in:
Daniel Stenberg
2013-08-05 23:49:53 +02:00
parent 230e16dc03
commit 7cc00d9a83
7 changed files with 101 additions and 39 deletions
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65
lib/ftp.c
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@@ -136,7 +136,7 @@ static CURLcode ftp_done(struct connectdata *conn,
CURLcode, bool premature);
static CURLcode ftp_connect(struct connectdata *conn, bool *done);
static CURLcode ftp_disconnect(struct connectdata *conn, bool dead_connection);
static CURLcode ftp_do_more(struct connectdata *conn, bool *completed);
static CURLcode ftp_do_more(struct connectdata *conn, int *completed);
static CURLcode ftp_multi_statemach(struct connectdata *conn, bool *done);
static int ftp_getsock(struct connectdata *conn, curl_socket_t *socks,
int numsocks);
@@ -1799,15 +1799,15 @@ static CURLcode ftp_state_quote(struct connectdata *conn,
static CURLcode ftp_epsv_disable(struct connectdata *conn)
{
CURLcode result = CURLE_OK;
infof(conn->data, "got positive EPSV response, but can't connect. "
"Disabling EPSV\n");
infof(conn->data, "Failed EPSV attempt. Disabling EPSV\n");
/* disable it for next transfer */
conn->bits.ftp_use_epsv = FALSE;
conn->data->state.errorbuf = FALSE; /* allow error message to get
rewritten */
PPSENDF(&conn->proto.ftpc.pp, "%s", "PASV");
conn->proto.ftpc.count1++;
/* remain in the FTP_PASV state */
/* remain in/go to the FTP_PASV state */
state(conn, FTP_PASV);
return result;
}
@@ -1936,15 +1936,7 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn,
}
else if(ftpc->count1 == 0) {
/* EPSV failed, move on to PASV */
/* disable it for next transfer */
conn->bits.ftp_use_epsv = FALSE;
infof(data, "disabling EPSV usage\n");
PPSENDF(&ftpc->pp, "%s", "PASV");
ftpc->count1++;
/* remain in the FTP_PASV state */
return result;
return ftp_epsv_disable(conn);
}
else {
failf(data, "Bad PASV/EPSV response: %03d", ftpcode);
@@ -2021,14 +2013,17 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn,
case CURLPROXY_SOCKS5_HOSTNAME:
result = Curl_SOCKS5(conn->proxyuser, conn->proxypasswd, newhost, newport,
SECONDARYSOCKET, conn);
connected = TRUE;
break;
case CURLPROXY_SOCKS4:
result = Curl_SOCKS4(conn->proxyuser, newhost, newport,
SECONDARYSOCKET, conn, FALSE);
connected = TRUE;
break;
case CURLPROXY_SOCKS4A:
result = Curl_SOCKS4(conn->proxyuser, newhost, newport,
SECONDARYSOCKET, conn, TRUE);
connected = TRUE;
break;
case CURLPROXY_HTTP:
case CURLPROXY_HTTP_1_0:
@@ -2080,8 +2075,7 @@ static CURLcode ftp_state_pasv_resp(struct connectdata *conn,
}
}
conn->bits.tcpconnect[SECONDARYSOCKET] = TRUE;
conn->bits.tcpconnect[SECONDARYSOCKET] = connected;
conn->bits.do_more = TRUE;
state(conn, FTP_STOP); /* this phase is completed */
@@ -3677,20 +3671,23 @@ static CURLcode ftp_range(struct connectdata *conn)
*
* This function shall be called when the second FTP (data) connection is
* connected.
*
* 'complete' can return 0 for incomplete, 1 for done and -1 for go back
* (which basically is only for when PASV is being sent to retry a failed
* EPSV).
*/
static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
static CURLcode ftp_do_more(struct connectdata *conn, int *completep)
{
struct SessionHandle *data=conn->data;
struct ftp_conn *ftpc = &conn->proto.ftpc;
CURLcode result = CURLE_OK;
bool connected = FALSE;
bool complete = FALSE;
/* the ftp struct is inited in ftp_connect() */
struct FTP *ftp = data->state.proto.ftp;
*complete = FALSE;
/* if the second connection isn't done yet, wait for it */
if(!conn->bits.tcpconnect[SECONDARYSOCKET]) {
if(conn->tunnel_state[SECONDARYSOCKET] == TUNNEL_CONNECT) {
@@ -3707,14 +3704,22 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
if(connected) {
DEBUGF(infof(data, "DO-MORE connected phase starts\n"));
}
else
else {
if(result && (ftpc->count1 == 0)) {
*completep = -1; /* go back to DOING please */
/* this is a EPSV connect failing, try PASV instead */
return ftp_epsv_disable(conn);
}
return result;
}
}
if(ftpc->state) {
/* already in a state so skip the intial commands.
They are only done to kickstart the do_more state */
result = ftp_multi_statemach(conn, complete);
result = ftp_multi_statemach(conn, &complete);
*completep = (int)complete;
/* if we got an error or if we don't wait for a data connection return
immediately */
@@ -3725,7 +3730,7 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
/* if we reach the end of the FTP state machine here, *complete will be
TRUE but so is ftpc->wait_data_conn, which says we need to wait for
the data connection and therefore we're not actually complete */
*complete = FALSE;
*completep = 0;
}
if(ftp->transfer <= FTPTRANSFER_INFO) {
@@ -3749,8 +3754,8 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
if(result)
return result;
*complete = TRUE; /* this state is now complete when the server has
connected back to us */
*completep = 1; /* this state is now complete when the server has
connected back to us */
}
}
else if(data->set.upload) {
@@ -3758,7 +3763,8 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
if(result)
return result;
result = ftp_multi_statemach(conn, complete);
result = ftp_multi_statemach(conn, &complete);
*completep = (int)complete;
}
else {
/* download */
@@ -3786,7 +3792,8 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
return result;
}
result = ftp_multi_statemach(conn, complete);
result = ftp_multi_statemach(conn, &complete);
*completep = (int)complete;
}
return result;
}
@@ -3798,7 +3805,7 @@ static CURLcode ftp_do_more(struct connectdata *conn, bool *complete)
if(!ftpc->wait_data_conn) {
/* no waiting for the data connection so this is now complete */
*complete = TRUE;
*completep = 1;
DEBUGF(infof(data, "DO-MORE phase ends with %d\n", (int)result));
}
@@ -3841,7 +3848,9 @@ CURLcode ftp_perform(struct connectdata *conn,
/* run the state-machine */
result = ftp_multi_statemach(conn, dophase_done);
*connected = conn->bits.tcpconnect[FIRSTSOCKET];
*connected = conn->bits.tcpconnect[SECONDARYSOCKET];
infof(conn->data, "ftp_perform ends with SECONDARY: %d\n", *connected);
if(*dophase_done)
DEBUGF(infof(conn->data, "DO phase is complete1\n"));
@@ -4469,7 +4478,7 @@ static CURLcode ftp_dophase_done(struct connectdata *conn,
struct ftp_conn *ftpc = &conn->proto.ftpc;
if(connected) {
bool completed;
int completed;
CURLcode result = ftp_do_more(conn, &completed);
if(result) {