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authorrofl0r <retnyg@gmx.net>2011-12-31 02:15:16 +0100
committerAndreas Schneider <asn@cryptomilk.org>2012-01-02 12:42:47 +0100
commit558b53a856c5df5efcee70f1ee0aba6cc10fe9ea (patch)
treed5471a5d7718dff967a8f40ea04e9f6c306c8888
parent0764adc82f2e25c77af73c7ffa03c0653694f0e1 (diff)
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session: Cleanup timeout functions and fix packets termination.
It is possible that we get unrelated packets while waiting for termination, thus waiting indefinitely. As a workaround we have to check the user-supplied timeout. Also cleaned up ssh_blocking_flush, which was using the timeout in a bogus manner (resetting the timeout after each check).
-rw-r--r--include/libssh/misc.h1
-rw-r--r--src/misc.c43
-rw-r--r--src/session.c32
3 files changed, 42 insertions, 34 deletions
diff --git a/include/libssh/misc.h b/include/libssh/misc.h
index f19dc00f..6812b0c2 100644
--- a/include/libssh/misc.h
+++ b/include/libssh/misc.h
@@ -78,6 +78,7 @@ const void *_ssh_list_pop_head(struct ssh_list *list);
#define ssh_list_pop_head(type, ssh_list)\
((type)_ssh_list_pop_head(ssh_list))
+int ssh_make_milliseconds(long sec, long usec);
void ssh_timestamp_init(struct ssh_timestamp *ts);
int ssh_timeout_elapsed(struct ssh_timestamp *ts, int timeout);
int ssh_timeout_update(struct ssh_timestamp *ts, int timeout);
diff --git a/src/misc.c b/src/misc.c
index 678961d8..a4c382b4 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -925,6 +925,24 @@ static int ssh_timestamp_difference(struct ssh_timestamp *old,
/**
* @internal
+ * @brief turn seconds and microseconds pair (as provided by user-set options)
+ * into millisecond value
+ * @param[in] sec number of seconds
+ * @param[in] usec number of microseconds
+ * @returns milliseconds, or 10000 if user supplied values are equal to zero
+ */
+int ssh_make_milliseconds(long sec, long usec) {
+ int res = usec ? (usec / 1000) : 0;
+ res += (sec * 1000);
+ if (res == 0) {
+ res = 10 * 1000; /* use a reasonable default value in case
+ * SSH_OPTIONS_TIMEOUT is not set in options. */
+ }
+ return res;
+}
+
+/**
+ * @internal
* @brief Checks if a timeout is elapsed, in function of a previous
* timestamp and an assigned timeout
* @param[in] ts pointer to an existing timestamp
@@ -934,17 +952,20 @@ static int ssh_timestamp_difference(struct ssh_timestamp *old,
* 0 otherwise
*/
int ssh_timeout_elapsed(struct ssh_timestamp *ts, int timeout) {
- struct ssh_timestamp now;
- if(timeout < 0)
- return 0; // -1 means infinite timeout
- if(timeout == 0)
- return 1; // 0 means no timeout
- ssh_timestamp_init(&now);
-
- if(ssh_timestamp_difference(ts,&now) >= timeout)
- return 1;
- else
- return 0;
+ struct ssh_timestamp now;
+ switch(timeout) {
+ case -2: // -2 means user-defined timeout as available in session->timeout, session->timeout_usec.
+ fprintf(stderr, "ssh_timeout_elapsed called with -2. this needs to be fixed. "
+ "please set a breakpoint on %s:%d and fix the caller\n", __FILE__, __LINE__);
+ case -1: // -1 means infinite timeout
+ return 0;
+ case 0: // 0 means no timeout
+ return 1;
+ default:
+ break;
+ }
+ ssh_timestamp_init(&now);
+ return (ssh_timestamp_difference(ts,&now) >= timeout);
}
/**
diff --git a/src/session.c b/src/session.c
index 121a6299..61c27b0f 100644
--- a/src/session.c
+++ b/src/session.c
@@ -304,7 +304,7 @@ int ssh_is_blocking(ssh_session session){
* @brief Blocking flush of the outgoing buffer
* @param[in] session The SSH session
* @param[in] timeout Set an upper limit on the time for which this function
- * will block, in milliseconds. Specifying a negative value
+ * will block, in milliseconds. Specifying -1
* means an infinite timeout. This parameter is passed to
* the poll() function.
* @returns SSH_OK on success, SSH_AGAIN if timeout occurred,
@@ -313,24 +313,16 @@ int ssh_is_blocking(ssh_session session){
int ssh_blocking_flush(ssh_session session, int timeout){
ssh_socket s;
- struct ssh_timestamp ts;
int rc = SSH_OK;
if(session==NULL)
return SSH_ERROR;
- enter_function();
s=session->socket;
- ssh_timestamp_init(&ts);
while (ssh_socket_buffered_write_bytes(s) > 0 && session->alive) {
- rc=ssh_handle_packets(session, timeout);
- if(ssh_timeout_elapsed(&ts,timeout)){
- rc=SSH_AGAIN;
- break;
- }
- timeout = ssh_timeout_update(&ts, timeout);
+ rc = ssh_handle_packets(session, timeout);
+ if(rc == SSH_AGAIN || rc == SSH_ERROR) break;
}
- leave_function();
return rc;
}
@@ -407,17 +399,6 @@ void ssh_set_fd_except(ssh_session session) {
ssh_socket_set_except(session->socket);
}
-static int ssh_make_milliseconds(long sec, long usec) {
- int res = usec ? (usec / 1000) : 0;
- res += (sec * 1000);
- if (res == 0) {
- res = 10 * 1000; /* use a reasonable default value in case
- * SSH_OPTIONS_TIMEOUT is not set in options. */
- }
-
- return res;
-}
-
/**
* @internal
*
@@ -497,13 +478,18 @@ int ssh_handle_packets(ssh_session session, int timeout) {
int ssh_handle_packets_termination(ssh_session session, int timeout,
ssh_termination_function fct, void *user){
int ret = SSH_OK;
-
+ struct ssh_timestamp ts;
+ ssh_timestamp_init(&ts);
while(!fct(user)){
ret = ssh_handle_packets(session, timeout);
if(ret == SSH_ERROR || ret == SSH_AGAIN)
return ret;
if(fct(user))
return SSH_OK;
+ else if(ssh_timeout_elapsed(&ts, timeout == -2 ? ssh_make_milliseconds(session->timeout, session->timeout_usec) : timeout))
+ /* it is possible that we get unrelated packets but still timeout our request,
+ * so simply relying on the poll timeout is not enough */
+ return SSH_AGAIN;
}
return ret;
}