Commit Graph

12 Commits (5381437664f588c67a424765dfeb3c28fa8092df)

Author SHA1 Message Date
Aaron Klotz 4dbdb19c26 net/tshttpproxy: fix incorrect type in Windows implementation, switch to mkwinsyscall, fix memory leak
The definition of winHTTPProxyInfo was using the wrong type (uint16 vs uint32)
for its first field. I fixed that type.

Furthermore, any UTF16 strings returned in that structure must be explicitly
freed. I added code to do this.

Finally, since this is the second time I've seen type safety errors in this code,
I switched the native API calls over to use wrappers generated by mkwinsyscall.
I know that would not have helped prevent the previous two problems, but every
bit helps IMHO.

Updates https://github.com/tailscale/tailscale/issues/4811

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Aaron Klotz 6e91f872af net/tshttpproxy: ensure we pass the correct flags to WinHttpOpen on Win7 and Win8.0
The best flag to use on Win7 and Win8.0 is deprecated in Win8.1, so we resolve
the flag depending on OS version info.

Fixes https://github.com/tailscale/tailscale/issues/4201

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
3 years ago
Josh Bleecher Snyder ca1b3fe235 net/tshttpproxy: use correct size for Windows BOOL argument
The Windows BOOL type is an int32. We were using a bool,
which is a one byte wide. This could be responsible for the
ERROR_INVALID_PARAMETER errors we were seeing for calls to
WinHttpGetProxyForUrl.

We manually checked all other existing Windows syscalls
for similar mistakes and did not find any.

Updates #879

Co-authored-by: Aaron Klotz <aaron@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 10f48087f4 net/tshttpproxy: call winhttp calls from a fixed OS thread
We often see things in logs like:

2021-03-02 17:52:45.2456258 +0800 +0800: winhttp: Open: The parameter is incorrect.
2021-03-02 17:52:45.2506261 +0800 +0800: tshttpproxy: winhttp: GetProxyForURL("https://log.tailscale.io/c/tailnode.log.tailscale.io/5037bb42f4bc330e2d6143e191a7ff7e837c6be538139231de69a439536e0d68"): ERROR_INVALID_PARAMETER [unexpected]

I have a hunch that WinHTTP has thread-local state. If so, this would fix it.
If not, this is pretty harmless.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 1036f51a56 net/tshttpproxy: aggressively rate-limit error logs in Transport.Proxy path
Otherwise log upload HTTP requests generate proxy errrors which
generate logs which generate HTTP requests which generate proxy
errors which generate more logs, etc.

Fixes #879
4 years ago
Brad Fitzpatrick 5bcac4eaac net/tshttpproxy: add GetProxyForURL negative cache
Otherwise when PAC server is down, we log, and each log entry is a new
HTTP request (from logtail) and a new GetProxyForURL call, which again
logs, non-stop. This is also nicer to the WinHTTP service.

Then also hook up link change notifications to the cache to reset it
if there's a chance the network might work sooner.
4 years ago
Brad Fitzpatrick 9c25968b63 net/tshttpproxy: fix typo in Windows code added at least second
I ran tests & vet & staticcheck, but for Linux, not Windows.
(#728 would be nice)
4 years ago
Brad Fitzpatrick b026a638c7 net/tshttpproxy: if winhttp.GetProxyForURL blocks too long, use previous value
We currently have a chickend-and-egg situation in some environments
where we can set up routes that WinHTTP's WPAD/PAC resolution service
needs to download the PAC file to evaluate GetProxyForURL, but the PAC
file is behind a route for which we need to call GetProxyForURL to
e.g. dial a DERP server.

As a short-term fix, just assume that the most recently returned proxy
is good enough for such situations.
4 years ago
Brad Fitzpatrick 74ee374667 net/tshttpproxy: add more winhttp logging
Notably around duration of calls.
4 years ago
Brad Fitzpatrick f915ab6552 net/tshttpproxy: add start of Kerberos Negotiate auth to proxies on Windows
For now only used by a new cmd/tailscale debug --get-url
subcommand. Not yet wired up to the places making HTTP requests.

Updates tailscale/corp#583
4 years ago
Brad Fitzpatrick 9be1917c5b net/tshttpproxy: discard secondary Windows proxies for now 4 years ago
Brad Fitzpatrick c5eb57f4d6 net/tshttpproxy: new package, support WPAD/PAC proxies on Windows
Updates tailscale/corp#553

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago