ports/libssh2
ports/libssh2
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Make _libssh2_sftp_read() fully non-blocking safe. This makes

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libssh2_sftp_readnb() non-blocking safe and libssh2_sftp_read() blocking
safe
Этот коммит содержится в:
James Housley 2007-04-22 13:13:51 +00:00
родитель 75ac861c7a
Коммит 42f0f69a35
1 изменённых файлов: 187 добавлений и 124 удалений
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311
src/sftp.c
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@ -74,6 +74,13 @@
#define SSH_FXP_EXTENDED 200 #define SSH_FXP_EXTENDED 200
#define SSH_FXP_EXTENDED_REPLY 201 #define SSH_FXP_EXTENDED_REPLY 201
typedef enum {
sftp_read_idle = 0,
sftp_read_packet_allocated,
sftp_read_packet_created,
sftp_read_packet_sent
} libssh2_sftp_read_state;
typedef enum { typedef enum {
sftp_readdir_idle = 0, sftp_readdir_idle = 0,
sftp_readdir_packet_created, sftp_readdir_packet_created,
@ -98,11 +105,17 @@ struct _LIBSSH2_SFTP {
/* Time that libssh2_sftp_packet_requirev() started reading */ /* Time that libssh2_sftp_packet_requirev() started reading */
time_t requirev_start; time_t requirev_start;
/* State variables used in _libssh2_sftp_read() */
libssh2_sftp_read_state read_state;
unsigned char *read_packet;
unsigned long read_request_id;
size_t read_total_read;
/* State variables used in _libssh2_sftp_readdir() */ /* State variables used in _libssh2_sftp_readdir() */
libssh2_sftp_readdir_state readdir_state; libssh2_sftp_readdir_state readdir_state;
unsigned char *readdir_packet; unsigned char *readdir_packet;
unsigned long readdir_request_id; unsigned long readdir_request_id;
}; };
#define LIBSSH2_SFTP_HANDLE_FILE 0 #define LIBSSH2_SFTP_HANDLE_FILE 0
@ -379,7 +392,9 @@ static int libssh2_sftp_packet_requirev(LIBSSH2_SFTP *sftp, int num_valid_respon
sftp->requirev_start = time(NULL); sftp->requirev_start = time(NULL);
/* Flush */ /* Flush */
int bl = libssh2_channel_get_blocking(sftp->channel);
while (libssh2_sftp_packet_read(sftp, 0, 1) > 0); while (libssh2_sftp_packet_read(sftp, 0, 1) > 0);
libssh2_channel_set_blocking(sftp->channel, bl);
} }
bl = libssh2_channel_get_blocking(sftp->channel); bl = libssh2_channel_get_blocking(sftp->channel);
@ -776,113 +791,161 @@ LIBSSH2_API LIBSSH2_SFTP_HANDLE *libssh2_sftp_open_ex(LIBSSH2_SFTP *sftp, const
/* {{{ _libssh2_sftp_read /* {{{ _libssh2_sftp_read
* Read from an SFTP file handle blocking/non-blocking depending on state * Read from an SFTP file handle blocking/non-blocking depending on state
*/ */
/* _libssh2_sftp_read - NB-UNSAFE?? */ /* _libssh2_sftp_read - NB-SAFE */
static ssize_t _libssh2_sftp_read(LIBSSH2_SFTP_HANDLE *handle, static ssize_t _libssh2_sftp_read(LIBSSH2_SFTP_HANDLE *handle, char *buffer,
char *buffer, size_t buffer_maxlen) size_t buffer_maxlen)
{ {
LIBSSH2_SFTP *sftp = handle->sftp; LIBSSH2_SFTP *sftp = handle->sftp;
LIBSSH2_CHANNEL *channel = sftp->channel; LIBSSH2_CHANNEL *channel = sftp->channel;
LIBSSH2_SESSION *session = channel->session; LIBSSH2_SESSION *session = channel->session;
unsigned long data_len, request_id; unsigned long data_len, request_id;
ssize_t packet_len = handle->handle_len + 25; /* packet_len(4) + packet_type(1) + request_id(4) + handle_len(4) + offset(8) + length(4) */ /* 25 = packet_len(4) + packet_type(1) + request_id(4) + handle_len(4) + offset(8) + length(4) */
unsigned char *packet, *s, *data; ssize_t packet_len = handle->handle_len + 25;
static const unsigned char read_responses[2] = { SSH_FXP_DATA, SSH_FXP_STATUS }; unsigned char *packet, *s, *data;
size_t bytes_read = 0; static const unsigned char read_responses[2] = { SSH_FXP_DATA, SSH_FXP_STATUS };
size_t bytes_requested = 0; size_t bytes_read = 0;
size_t total_read = 0; size_t bytes_requested = 0;
int rc; size_t total_read = 0;
int retcode;
if (sftp->read_state == sftp_read_idle) {
_libssh2_debug(session, LIBSSH2_DBG_SFTP, "Reading %lu bytes from SFTP handle", (unsigned long)buffer_maxlen); _libssh2_debug(session, LIBSSH2_DBG_SFTP, "Reading %lu bytes from SFTP handle", (unsigned long)buffer_maxlen);
packet = LIBSSH2_ALLOC(session, packet_len); packet = LIBSSH2_ALLOC(session, packet_len);
if (!packet) { if (!packet) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for FXP_CLOSE packet", 0); libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for FXP_CLOSE packet", 0);
return -1; return -1;
} }
sftp->read_state = sftp_read_packet_allocated;
while (total_read < buffer_maxlen) { } else {
s = packet; packet = sftp->read_packet;
/* If buffer_maxlen bytes will be requested, server may return request_id = sftp->read_request_id;
* all with one packet. But libssh2 have packet length total_read = sftp->read_total_read;
* limit. So we request data by pieces. */ }
bytes_requested = buffer_maxlen - total_read;
if (bytes_requested > LIBSSH2_SFTP_PACKET_MAXLEN-10) /* packet_type(1)+request_id(4)+data_length(4)+end_of_line_flag(1) */ while (total_read < buffer_maxlen) {
bytes_requested = LIBSSH2_SFTP_PACKET_MAXLEN-10; s = packet;
/*
#ifdef LIBSSH2_DEBUG_SFTP * If buffer_maxlen bytes will be requested, server may return all
_libssh2_debug(session, LIBSSH2_DBG_SFTP, "Requesting %lu bytes from SFTP handle", (unsigned long)bytes_requested); * with one packet. But libssh2 have packet length limit.
#endif * So we request data by pieces.
*/
libssh2_htonu32(s, packet_len - 4); bytes_requested = buffer_maxlen - total_read;
s += 4; /* 10 = packet_type(1)+request_id(4)+data_length(4)+end_of_line_flag(1) */
*(s++) = SSH_FXP_READ; if (bytes_requested > LIBSSH2_SFTP_PACKET_MAXLEN - 10) {
request_id = sftp->request_id++; bytes_requested = LIBSSH2_SFTP_PACKET_MAXLEN - 10;
libssh2_htonu32(s, request_id);
s += 4;
libssh2_htonu32(s, handle->handle_len);
s += 4;
memcpy(s, handle->handle, handle->handle_len);
s += handle->handle_len;
libssh2_htonu64(s, handle->u.file.offset);
s += 8;
libssh2_htonu32(s, buffer_maxlen);
s += 4;
if (packet_len != libssh2_channel_write(channel, (char *)packet,
packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send FXP_READ command", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
/* #warning "XXX - Looping on PACKET_EAGAIN (blocking) until fix is migrated up farther" */
while ((rc = libssh2_sftp_packet_requirev(sftp, 2, read_responses, request_id, &data, &data_len)) == PACKET_EAGAIN) {
;
}
if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_TIMEOUT,
"Timeout waiting for status message", 0);
return -1;
}
switch (data[0]) {
case SSH_FXP_STATUS: {
int retcode = libssh2_ntohu32(data + 5);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, data);
if (retcode == LIBSSH2_FX_EOF) {
return total_read;
} else {
sftp->last_errno = retcode;
libssh2_error(session, LIBSSH2_ERROR_SFTP_PROTOCOL, "SFTP Protocol Error", 0);
return -1;
}
}
case SSH_FXP_DATA:
bytes_read = libssh2_ntohu32(data + 5);
if (bytes_read > (data_len - 9)) {
return -1;
}
#ifdef LIBSSH2_DEBUG_SFTP
_libssh2_debug(session, LIBSSH2_DBG_SFTP,
"%lu bytes returned",
(unsigned long)bytes_read);
#endif
memcpy(buffer + total_read, data + 9, bytes_read);
handle->u.file.offset += bytes_read;
total_read += bytes_read;
LIBSSH2_FREE(session, data);
}
} }
LIBSSH2_FREE(session, packet); #ifdef LIBSSH2_DEBUG_SFTP
return total_read; _libssh2_debug(session, LIBSSH2_DBG_SFTP, "Requesting %lu bytes from SFTP handle", (unsigned long)bytes_requested);
#endif
if (sftp->read_state == sftp_read_packet_allocated) {
libssh2_htonu32(s, packet_len - 4);
s += 4;
*(s++) = SSH_FXP_READ;
request_id = sftp->request_id++;
libssh2_htonu32(s, request_id);
s += 4;
libssh2_htonu32(s, handle->handle_len);
s += 4;
memcpy(s, handle->handle, handle->handle_len);
s += handle->handle_len;
libssh2_htonu64(s, handle->u.file.offset);
s += 8;
libssh2_htonu32(s, buffer_maxlen);
s += 4;
sftp->read_state = sftp_read_packet_created;
}
if (sftp->read_state != sftp_read_packet_sent) {
if (libssh2_channel_get_blocking(channel)) {
if (packet_len != libssh2_channel_write(channel, (char *)packet, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send FXP_READ command", 0);
LIBSSH2_FREE(session, packet);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
return -1;
}
} else {
if ((retcode = libssh2_channel_writenb(channel, (char *)packet, packet_len)) == PACKET_EAGAIN) {
sftp->read_packet = packet;
sftp->read_request_id = request_id;
sftp->read_total_read = total_read;
return PACKET_EAGAIN;
}
else if (packet_len != retcode) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send FXP_READ command", 0);
LIBSSH2_FREE(session, packet);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
return -1;
}
}
sftp->read_packet = packet;
sftp->read_request_id = request_id;
sftp->read_total_read = total_read;
sftp->read_state = sftp_read_packet_sent;
}
retcode = libssh2_sftp_packet_requirev(sftp, 2, read_responses, request_id, &data, &data_len);
if (retcode == PACKET_EAGAIN) {
return PACKET_EAGAIN;
}
else if (retcode) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_TIMEOUT, "Timeout waiting for status message", 0);
LIBSSH2_FREE(session, packet);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
return -1;
}
switch (data[0]) {
case SSH_FXP_STATUS:
retcode = libssh2_ntohu32(data + 5);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, data);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
if (retcode == LIBSSH2_FX_EOF) {
return total_read;
} else {
sftp->last_errno = retcode;
libssh2_error(session, LIBSSH2_ERROR_SFTP_PROTOCOL, "SFTP Protocol Error", 0);
return -1;
}
case SSH_FXP_DATA:
bytes_read = libssh2_ntohu32(data + 5);
if (bytes_read > (data_len - 9)) {
LIBSSH2_FREE(session, packet);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
return -1;
}
#ifdef LIBSSH2_DEBUG_SFTP
_libssh2_debug(session, LIBSSH2_DBG_SFTP, "%lu bytes returned", (unsigned long)bytes_read);
#endif
memcpy(buffer + total_read, data + 9, bytes_read);
handle->u.file.offset += bytes_read;
total_read += bytes_read;
LIBSSH2_FREE(session, data);
/*
* Set the state back to allocated, so a new one will be
* created to either request more data or get EOF
*/
sftp->read_state = sftp_read_packet_allocated;
}
}
LIBSSH2_FREE(session, packet);
sftp->read_packet = NULL;
sftp->read_state = sftp_read_idle;
return total_read;
} }
/* {{{ libssh2_sftp_read /* {{{ libssh2_sftp_read
* Read from an SFTP file handle blocking * Read from an SFTP file handle blocking
@ -891,25 +954,25 @@ static ssize_t _libssh2_sftp_read(LIBSSH2_SFTP_HANDLE *handle,
LIBSSH2_API ssize_t libssh2_sftp_read(LIBSSH2_SFTP_HANDLE *handle, LIBSSH2_API ssize_t libssh2_sftp_read(LIBSSH2_SFTP_HANDLE *handle,
char *buffer, size_t buffer_maxlen) char *buffer, size_t buffer_maxlen)
{ {
ssize_t rc; ssize_t rc;
LIBSSH2_CHANNEL *ch = handle->sftp->channel; LIBSSH2_CHANNEL *ch = handle->sftp->channel;
int bl = libssh2_channel_get_blocking(ch); int bl = libssh2_channel_get_blocking(ch);
/* set blocking */ /* set blocking */
libssh2_channel_set_blocking(ch, 1); libssh2_channel_set_blocking(ch, 1);
rc = _libssh2_sftp_read(handle, buffer, buffer_maxlen); rc = _libssh2_sftp_read(handle, buffer, buffer_maxlen);
/* restore state */ /* restore state */
libssh2_channel_set_blocking(ch, bl); libssh2_channel_set_blocking(ch, bl);
if(rc < 0) { if(rc < 0) {
/* precent accidental returning of other return codes since /* precent accidental returning of other return codes since
this API does not support/provide those */ this API does not support/provide those */
return -1; return -1;
} }
return rc; return rc;
} }
/* }}} */ /* }}} */