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sftp_packet_read: follow-up fix for EAGAIN/window adjust

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The commit in 7194a9bd7ba45 wasn't complete. This change makes sure
variables are initialized properly before used in the EAGAIN and window
adjust cases.
This commit is contained in:
Daniel Stenberg 2012-03-13 22:02:14 +01:00
parent a1c996cef1
commit bf097e37b0
1 changed files with 40 additions and 39 deletions
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79
src/sftp.c
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@ -213,34 +213,35 @@ sftp_packet_read(LIBSSH2_SFTP *sftp)
{
LIBSSH2_CHANNEL *channel = sftp->channel;
LIBSSH2_SESSION *session = channel->session;
unsigned char *packet;
size_t packet_received;
unsigned char *packet = NULL;
ssize_t rc;
uint32_t packet_len; /* 32bits on the wire */
uint32_t adjust;
unsigned long recv_window;
_libssh2_debug(session, LIBSSH2_TRACE_SFTP, "recv packet");
switch(sftp->packet_state) {
case libssh2_NB_state_sent:
case libssh2_NB_state_sent: /* EAGAIN from window adjusting */
sftp->packet_state = libssh2_NB_state_idle;
packet = sftp->partial_packet;
goto window_adjust;
case libssh2_NB_state_sent1: /* EAGAIN from channel read */
sftp->packet_state = libssh2_NB_state_idle;
packet = sftp->partial_packet;
_libssh2_debug(session, LIBSSH2_TRACE_SFTP,
"partial read cont, len: %lu", sftp->partial_len);
_libssh2_debug(session, LIBSSH2_TRACE_SFTP,
"partial read cont, already recvd: %lu",
sftp->partial_received);
/* fall-through */
default:
if(!packet) {
/* only do this if there's not already a packet buffer allocated
to use */
/* If there was a previous partial, start using it */
if (sftp->partial_packet) {
packet = sftp->partial_packet;
packet_len = sftp->partial_len;
packet_received = sftp->partial_received;
sftp->partial_packet = NULL;
_libssh2_debug(session, LIBSSH2_TRACE_SFTP,
"partial read cont, len: %lu", packet_len);
}
else {
/* each packet starts with a 32 bit length field */
rc = _libssh2_channel_read(channel, 0,
(char *)&sftp->partial_size[
@ -257,35 +258,33 @@ sftp_packet_read(LIBSSH2_SFTP *sftp)
/* we got a short read for the length part */
return LIBSSH2_ERROR_EAGAIN;
packet_len = _libssh2_ntohu32(sftp->partial_size);
sftp->partial_len = _libssh2_ntohu32(sftp->partial_size);
/* make sure we don't proceed if the packet size is unreasonably
large */
if (packet_len > LIBSSH2_SFTP_PACKET_MAXLEN)
if (sftp->partial_len > LIBSSH2_SFTP_PACKET_MAXLEN)
return _libssh2_error(session,
LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED,
"SFTP packet too large");
_libssh2_debug(session, LIBSSH2_TRACE_SFTP,
"Data begin - Packet Length: %lu", packet_len);
packet = LIBSSH2_ALLOC(session, packet_len);
"Data begin - Packet Length: %lu",
sftp->partial_len);
packet = LIBSSH2_ALLOC(session, sftp->partial_len);
if (!packet)
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate SFTP packet");
"Unable to allocate SFTP packet");
sftp->partial_size_len = 0;
packet_received = 0;
sftp->partial_received = 0; /* how much of the packet already
received */
sftp->partial_packet = packet;
sftp->partial_len = packet_len;
sftp->partial_received = packet_received;
window_adjust:
window_adjust:
recv_window = libssh2_channel_window_read_ex(channel, NULL, NULL);
/* how much data to ask for */
adjust = sftp->partial_len - sftp->partial_received;
if(adjust > recv_window) {
if(sftp->partial_len > recv_window) {
/* ask for twice the data amount we need at once */
rc = _libssh2_channel_receive_window_adjust(channel, adjust*2,
rc = _libssh2_channel_receive_window_adjust(channel,
sftp->partial_len*2,
0, NULL);
/* store the state so that we continue with the correct
operation at next invoke */
@ -299,10 +298,11 @@ sftp_packet_read(LIBSSH2_SFTP *sftp)
}
/* Read as much of the packet as we can */
while (packet_len > packet_received) {
while (sftp->partial_len > sftp->partial_received) {
rc = _libssh2_channel_read(channel, 0,
(char *) packet + packet_received,
packet_len - packet_received);
(char *)&packet[sftp->partial_received],
sftp->partial_len -
sftp->partial_received);
if (rc == LIBSSH2_ERROR_EAGAIN) {
/*
@ -310,28 +310,29 @@ sftp_packet_read(LIBSSH2_SFTP *sftp)
* the caller. Set 'partial_packet' so that this function
* knows how to continue on the next invoke.
*/
sftp->partial_packet = packet;
sftp->packet_state = libssh2_NB_state_sent1;
return rc;
}
else if (rc < 0) {
LIBSSH2_FREE(session, packet);
sftp->partial_packet = NULL;
return _libssh2_error(session, rc,
"Error waiting for SFTP packet");
}
packet_received += rc;
sftp->partial_received += rc;
}
sftp->partial_packet = NULL;
rc = sftp_packet_add(sftp, packet, packet_len);
rc = sftp_packet_add(sftp, packet, sftp->partial_len);
if (rc) {
LIBSSH2_FREE(session, packet);
return rc;
}
return packet[0];
}
/* WON'T REACH */
}
/*
* sftp_packetlist_flush