Commit graph

125 commits

Author SHA1 Message Date
Jeff King
b725b270d1 remote-curl: use error instead of fprintf(stderr)
We usually prefix our error messages with "error: ", but
many error messages from remote-curl are simply printed with
fprintf. This can make the output a little harder to read
(especially because such message may be intermingled with
errors from the parent git process).

There is no reason to avoid error(), as we are already
calling it many places (in addition to libgit.a functions
which use it).

While we're adjusting the messages, we can also drop the
capitalization which makes them unlike other git error
messages.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-10 10:53:47 -07:00
Jeff King
37943e4c38 remote-curl: do not complain on EOF from parent git
The parent git process is supposed to send us an empty line
to indicate that the conversation is over. However, the
parent process may die() if there is a problem with the
operation (e.g., we try to fetch a ref that does not exist).
In this case, it produces a useful message, but then
remote-curl _also_ produces an unhelpful message:

  $ git pull origin matser
  fatal: couldn't find remote ref matser
  Unexpected end of command stream

The "right" way to fix this is to teach the parent git to
always cleanly close the connection to the helper, letting
it know that we are done. Implementing that is rather
clunky, though, as it would involve either replacing die()
operations with returning errors up the stack (until we
disconnect the transport), or adding an atexit handler to
clean up any transport helpers left open.

It's much simpler to just suppress the EOF message in
remote-curl. It was not added to address any real-world
situation in the first place, but rather a "we should
probably report unexpected things" suggestion[1].

It is the parent git which drives the operation, and whose
exit value actually matters. If the parent dies, then the
helper has no need to complain (except as a debugging aid).
In the off chance that the pipe is closed without the parent
dying, it can still notice the non-zero exit code.

[1] http://article.gmane.org/gmane.comp.version-control.git/176036

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-10 10:53:00 -07:00
Junio C Hamano
92251b1b5b Merge branch 'nd/shallow-clone'
Fetching from a shallow-cloned repository used to be forbidden,
primarily because the codepaths involved were not carefully vetted
and we did not bother supporting such usage. This attempts to allow
object transfer out of a shallow-cloned repository in a controlled
way (i.e. the receiver become a shallow repository with truncated
history).

* nd/shallow-clone: (31 commits)
  t5537: fix incorrect expectation in test case 10
  shallow: remove unused code
  send-pack.c: mark a file-local function static
  git-clone.txt: remove shallow clone limitations
  prune: clean .git/shallow after pruning objects
  clone: use git protocol for cloning shallow repo locally
  send-pack: support pushing from a shallow clone via http
  receive-pack: support pushing to a shallow clone via http
  smart-http: support shallow fetch/clone
  remote-curl: pass ref SHA-1 to fetch-pack as well
  send-pack: support pushing to a shallow clone
  receive-pack: allow pushes that update .git/shallow
  connected.c: add new variant that runs with --shallow-file
  add GIT_SHALLOW_FILE to propagate --shallow-file to subprocesses
  receive/send-pack: support pushing from a shallow clone
  receive-pack: reorder some code in unpack()
  fetch: add --update-shallow to accept refs that update .git/shallow
  upload-pack: make sure deepening preserves shallow roots
  fetch: support fetching from a shallow repository
  clone: support remote shallow repository
  ...
2014-01-17 12:21:20 -08:00
Junio C Hamano
ad70448576 Merge branch 'cc/starts-n-ends-with'
Remove a few duplicate implementations of prefix/suffix comparison
functions, and rename them to starts_with and ends_with.

* cc/starts-n-ends-with:
  replace {pre,suf}fixcmp() with {starts,ends}_with()
  strbuf: introduce starts_with() and ends_with()
  builtin/remote: remove postfixcmp() and use suffixcmp() instead
  environment: normalize use of prefixcmp() by removing " != 0"
2013-12-17 12:02:44 -08:00
Nguyễn Thái Ngọc Duy
16094885ca smart-http: support shallow fetch/clone
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:18 -08:00
Nguyễn Thái Ngọc Duy
58f2ed051f remote-curl: pass ref SHA-1 to fetch-pack as well
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:18 -08:00
Nguyễn Thái Ngọc Duy
b06dcd7d68 connect.c: teach get_remote_heads to parse "shallow" lines
No callers pass a non-empty pointer as shallow_points at this
stage. As a result, all clients still refuse to talk to shallow
repository on the other end.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:16 -08:00
Christian Couder
5955654823 replace {pre,suf}fixcmp() with {starts,ends}_with()
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.

The change can be recreated by mechanically applying this:

    $ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
      grep -v strbuf\\.c |
      xargs perl -pi -e '
        s|!prefixcmp\(|starts_with\(|g;
        s|prefixcmp\(|!starts_with\(|g;
        s|!suffixcmp\(|ends_with\(|g;
        s|suffixcmp\(|!ends_with\(|g;
      '

on the result of preparatory changes in this series.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-05 14:13:21 -08:00
Junio C Hamano
c5a77e8f92 Merge branch 'bc/http-100-continue'
Issue "100 Continue" responses to help use of GSS-Negotiate
authentication scheme over HTTP transport when needed.

* bc/http-100-continue:
  remote-curl: fix large pushes with GSSAPI
  remote-curl: pass curl slot_results back through run_slot
  http: return curl's AUTHAVAIL via slot_results
2013-12-05 12:58:59 -08:00
Brian M. Carlson
c80d96ca0c remote-curl: fix large pushes with GSSAPI
Due to an interaction between the way libcurl handles GSSAPI
authentication over HTTP and the way git uses libcurl, large
pushes (those over http.postBuffer bytes) would fail due to
an authentication failure requiring a rewind of the curl
buffer.  Such a rewind was not possible because the data did
not fit into the entire buffer.

Enable the use of the Expect: 100-continue header for large
requests where the server offers GSSAPI authentication to
avoid this issue, since the request would otherwise fail.
This allows git to get the authentication data right before
sending the pack contents.  Existing cases where pushes
would succeed, including small requests using GSSAPI, still
disable the use of 100 Continue, as it causes problems for
some remote HTTP implementations (servers and proxies).

Signed-off-by: Brian M. Carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
2013-10-31 10:13:40 -07:00
Jeff King
3a347ed707 remote-curl: pass curl slot_results back through run_slot
Some callers may want to know more than just the integer
error code we return. Let them optionally pass a
slot_results struct to fill in (or NULL if they do not
care). In either case we continue to return the integer
code.

We can also give probe_rpc the same treatment (since it
builds directly on run_slot).

Signed-off-by: Jeff King <peff@peff.net>
2013-10-31 10:05:59 -07:00
Junio C Hamano
177f0a4009 Merge branch 'jk/http-auth-redirects'
Handle the case where http transport gets redirected during the
authorization request better.

* jk/http-auth-redirects:
  http.c: Spell the null pointer as NULL
  remote-curl: rewrite base url from info/refs redirects
  remote-curl: store url as a strbuf
  remote-curl: make refs_url a strbuf
  http: update base URLs when we see redirects
  http: provide effective url to callers
  http: hoist credential request out of handle_curl_result
  http: refactor options to http_get_*
  http_request: factor out curlinfo_strbuf
  http_get_file: style fixes
2013-10-30 12:09:53 -07:00
Jeff King
050ef3655c remote-curl: rewrite base url from info/refs redirects
For efficiency and security reasons, an earlier commit in
this series taught http_get_* to re-write the base url based
on redirections we saw while making a specific request.

This commit wires that option into the info/refs request,
meaning that a redirect from

    http://example.com/foo.git/info/refs

to

    https://example.com/bar.git/info/refs

will behave as if "https://example.com/bar.git" had been
provided to git in the first place.

The tests bear some explanation. We introduce two new
hierearchies into the httpd test config:

  1. Requests to /smart-redir-limited will work only for the
     initial info/refs request, but not any subsequent
     requests. As a result, we can confirm whether the
     client is re-rooting its requests after the initial
     contact, since otherwise it will fail (it will ask for
     "repo.git/git-upload-pack", which is not redirected).

  2. Requests to smart-redir-auth will redirect, and require
     auth after the redirection. Since we are using the
     redirected base for further requests, we also update
     the credential struct, in order not to mislead the user
     (or credential helpers) about which credential is
     needed. We can therefore check the GIT_ASKPASS prompts
     to make sure we are prompting for the new location.
     Because we have neither multiple servers nor https
     support in our test setup, we can only redirect between
     paths, meaning we need to turn on
     credential.useHttpPath to see the difference.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 17:01:34 -07:00
Jeff King
b227bbc43a remote-curl: store url as a strbuf
We use a strbuf to generate the string containing the remote
URL, but then detach it to a bare pointer. This makes it
harder to later manipulate the URL, as we have forgotten the
length (and the allocation semantics are not as clear).

Let's instead keep the strbuf around. As a bonus, this
eliminates a confusing double-use of the "buf" strbuf in
main(). Prior to this, it was used both for constructing the
url, and for reading commands from stdin.

The downside is that we have to update each call site to
refer to "url.buf" rather than just "url" when they want the
C string.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 17:01:15 -07:00
Jeff King
c65d5692cd remote-curl: make refs_url a strbuf
In the discover_refs function, we use a strbuf named
"buffer" for multiple purposes. First we build the info/refs
URL in it, and then detach that to a bare pointer. Then, we
use the same strbuf to store the result of fetching the
refs.

Let's instead keep a separate refs_url strbuf. This is less
confusing, as the "buffer" strbuf is now used for only one
thing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 16:57:04 -07:00
Jeff King
2501aff8b7 http: hoist credential request out of handle_curl_result
When we are handling a curl response code in http_request or
in the remote-curl RPC code, we use the handle_curl_result
helper to translate curl's response into an easy-to-use
code. When we see an HTTP 401, we do one of two things:

  1. If we already had a filled-in credential, we mark it as
     rejected, and then return HTTP_NOAUTH to indicate to
     the caller that we failed.

  2. If we didn't, then we ask for a new credential and tell
     the caller HTTP_REAUTH to indicate that they may want
     to try again.

Rejecting in the first case makes sense; it is the natural
result of the request we just made. However, prompting for
more credentials in the second step does not always make
sense. We do not know for sure that the caller is going to
make a second request, and nor are we sure that it will be
to the same URL. Logically, the prompt belongs not to the
request we just finished, but to the request we are (maybe)
about to make.

In practice, it is very hard to trigger any bad behavior.
Currently, if we make a second request, it will always be to
the same URL (even in the face of redirects, because curl
handles the redirects internally). And we almost always
retry on HTTP_REAUTH these days. The one exception is if we
are streaming a large RPC request to the server (e.g., a
pushed packfile), in which case we cannot restart. It's
extremely unlikely to see a 401 response at this stage,
though, as we would typically have seen it when we sent a
probe request, before streaming the data.

This patch drops the automatic prompt out of case 2, and
instead requires the caller to do it. This is a few extra
lines of code, and the bug it fixes is unlikely to come up
in practice. But it is conceptually cleaner, and paves the
way for better handling of credentials across redirects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 16:55:13 -07:00
Jeff King
1bbcc224cc http: refactor options to http_get_*
Over time, the http_get_strbuf function has grown several
optional parameters. We now have a bitfield with multiple
boolean options, as well as an optional strbuf for returning
the content-type of the response. And a future patch in this
series is going to add another strbuf option.

Treating these as separate arguments has a few downsides:

  1. Most call sites need to add extra NULLs and 0s for the
     options they aren't interested in.

  2. The http_get_* functions are actually wrappers around
     2 layers of low-level implementation functions. We have
     to pass these options through individually.

  3. The http_get_strbuf wrapper learned these options, but
     nobody bothered to do so for http_get_file, even though
     it is backed by the same function that does understand
     the options.

Let's consolidate the options into a single struct. For the
common case of the default options, we'll allow callers to
simply pass a NULL for the options struct.

The resulting code is often a few lines longer, but it ends
up being easier to read (and to change as we add new
options, since we do not need to update each call site).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-30 17:21:59 -07:00
Junio C Hamano
2233ad4534 Merge branch 'jc/push-cas'
Allow a safer "rewind of the remote tip" push than blind "--force",
by requiring that the overwritten remote ref to be unchanged since
the new history to replace it was prepared.

The machinery is more or less ready.  The "--force" option is again
the big red button to override any safety, thanks to J6t's sanity
(the original round allowed --lockref to defeat --force).

The logic to choose the default implemented here is fragile
(e.g. "git fetch" after seeing a failure will update the
remote-tracking branch and will make the next "push" pass,
defeating the safety pretty easily).  It is suitable only for the
simplest workflows, and it may hurt users more than it helps them.

* jc/push-cas:
  push: teach --force-with-lease to smart-http transport
  send-pack: fix parsing of --force-with-lease option
  t5540/5541: smart-http does not support "--force-with-lease"
  t5533: test "push --force-with-lease"
  push --force-with-lease: tie it all together
  push --force-with-lease: implement logic to populate old_sha1_expect[]
  remote.c: add command line option parser for "--force-with-lease"
  builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN
  cache.h: move remote/connect API out of it
2013-09-09 14:30:29 -07:00
Junio C Hamano
711b276974 Merge branch 'nd/clone-connectivity-shortcut'
* nd/clone-connectivity-shortcut:
  smart http: use the same connectivity check on cloning
2013-09-09 14:30:01 -07:00
Junio C Hamano
05c1eb1034 push: teach --force-with-lease to smart-http transport
We have been passing enough information to enable the
compare-and-swap logic down to the transport layer, but the
transport helper was not passing it to smart-http transport.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-02 16:11:06 -07:00
Nguyễn Thái Ngọc Duy
9ba380481c smart http: use the same connectivity check on cloning
This is an extension of c6807a4 (clone: open a shortcut for
connectivity check - 2013-05-26) to reduce the cost of connectivity
check at clone time, this time with smart http protocol.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-23 12:18:18 -07:00
Junio C Hamano
222b1212c1 remote-http: use argv-array
Instead of using a hand-managed argument array, use argv-array API
to manage dynamically formulated command line.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-09 12:34:16 -07:00
Jeff King
de89f0b25a remote-curl: die directly with http error messages
When we encounter an unknown http error (e.g., a 403), we
hand the error code to http_error, which then prints it with
error(). After that we die with the redundant message "HTTP
request failed".

Instead, let's just drop http_error entirely, which does
nothing but pass arguments to error(), and instead die
directly with a useful message.

So before:

  $ git clone https://example.com/repo.git
  Cloning into 'repo'...
  error: unable to access 'https://example.com/repo.git': The requested URL returned error: 403 Forbidden
  fatal: HTTP request failed

and after:

  $ git clone https://example.com/repo.git
  Cloning into 'repo'...
  fatal: unable to access 'https://example.com/repo.git': The requested URL returned error: 403 Forbidden

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:45 -07:00
Jeff King
67d2a7b5c5 http: simplify http_error helper function
This helper function should really be a one-liner that
prints an error message, but it has ended up unnecessarily
complicated:

  1. We call error() directly when we fail to start the curl
     request, so we must later avoid printing a duplicate
     error in http_error().

     It would be much simpler in this case to just stuff the
     error message into our usual curl_errorstr buffer
     rather than printing it ourselves. This means that
     http_error does not even have to care about curl's exit
     value (the interesting part is in the errorstr buffer
     already).

  2. We return the "ret" value passed in to us, but none of
     the callers actually cares about our return value. We
     can just drop this entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:44 -07:00
Jeff King
d5ccbe4dfb remote-curl: consistently report repo url for http errors
When we report http errors in fetching the initial ref
advertisement, we show the full URL we attempted to use,
including "info/refs?service=git-upload-pack". While this
may be useful for debugging a broken server, it is
unnecessarily verbose and confusing for most cases, in which
the client user is not even the same person as the owner of
the repository.

Let's just show the repository URL; debugging can happen
with GIT_CURL_VERBOSE, which shows way more useful
information, anyway.

At the same time, let's also make sure to mention the
repository URL when we report failed authentication
(previously we said only "Authentication failed"). Knowing
the URL can help the user realize why authentication failed
(e.g., they meant to push to remote A, not remote B).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:43 -07:00
Jeff King
cfa0f4040d remote-curl: always show friendlier 404 message
When we get an http 404 trying to get the initial list of
refs from the server, we try to be helpful and remind the
user that update-server-info may need to be run. This looks
like:

  $ git clone https://github.com/non/existent
  Cloning into 'existent'...
  fatal: https://github.com/non/existent/info/refs?service=git-upload-pack not found: did you run git update-server-info on the server?

Suggesting update-server-info may be a good suggestion for
users who are in control of the server repo and who are
planning to set up dumb http. But for users of smart http,
and especially users who are not in control of the server
repo, the advice is useless and confusing.

Since most people are expected to use smart http these days,
it does not make sense to keep the update-server-info hint.

We not only drop the mention of update-server-info, but also
show only the main repo URL, not the full "info/refs" and
service parameter. These elements may be useful for
debugging a broken server configuration, but in the majority
of cases, users are not fetching from their own
repositories, but rather from other people's repositories;
they have neither the power nor interest to fix a broken
configuration, and the extra components just make the
message more confusing. Users who do want to debug can and
should use GIT_CURL_VERBOSE to get more complete information
on the actual URLs visited.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:43 -07:00
Jeff King
110bcdc3d0 remote-curl: let servers override http 404 advice
When we get an http 404 trying to get the initial list of
refs from the server, we try to be helpful and remind the
user that update-server-info may need to be run. This looks
like:

  $ git clone https://github.com/non/existent
  Cloning into 'existent'...
  fatal: https://github.com/non/existent/info/refs?service=git-upload-pack not found: did you run git update-server-info on the server?

Suggesting update-server-info may be a good suggestion for
users who are in control of the server repo and who are
planning to set up dumb http. But for users of smart http,
and especially users who are not in control of the server
repo, the advice is useless and confusing.

The previous patch taught remote-curl to show custom advice
from the server when it is available. When we have shown
messages from the server, we can also drop our custom
advice; what the server has to say is likely to be more
accurate and helpful.

We not only drop the mention of update-server-info, but also
show only the main repo URL, not the full "info/refs" and
service parameter. These elements may be useful for
debugging a broken server configuration, but again, anything
the server has provided is likely to be more useful (and one
can still use GIT_CURL_VERBOSE to get much more complete
debugging information).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:42 -07:00
Jeff King
426e70d4a1 remote-curl: show server content on http errors
If an http request to a remote git server fails, we show
only the http response code, or sometimes a custom message
for particular codes. This gives the server no opportunity
to offer a more detailed explanation of the reason for the
failure, or to give extra advice.

This patch teaches remote-curl to record and display the
body content of a failed http response. We only display such
responses when the content-type is advertised as text/plain,
as it is the most likely to look presentable on the user's
terminal (and it is hoped to be a good indication that the
message is intended for git clients, and not for a web
browser).

Each line of the new output is prepended with "remote:".
Example output may look like this (assuming the server is
configured to display such a helpful message):

  $ GIT_SMART_HTTP=0 git clone https://example.com/some/repo.git
  Cloning into 'repo'...
  remote: Sorry, fetching via dumb http is forbidden.
  remote: Please upgrade your git client to v1.6.6 or greater
  remote: and make sure that smart-http is enabled.
  error: The requested URL returned error: 403 while accessing http://localhost:5001/some/repo.git/info/refs
  fatal: HTTP request failed

For the sake of simplicity, we only record and display these
errors during the initial fetch of the ref list, as that is
the initial contact with the server and where the most
common, interesting errors happen (and there is already
precedent, as that is the only place we currently massage
http error codes into more helpful messages).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 18:56:42 -07:00
Jeff King
2a4552021a remote-curl: always parse incoming refs
When remote-curl receives a list of refs from a server, it
keeps the whole buffer intact. When we get a "list" command,
we feed the result to get_remote_heads, and when we get a
"fetch" or "push" command, we feed it to fetch-pack or
send-pack, respectively.

If the HTTP response from the server is truncated for any
reason, we will get an incomplete ref advertisement. If we
then feed this incomplete list to fetch-pack, one of a few
things may happen:

  1. If the truncation is in a packet header, fetch-pack
     will notice the bogus line and complain.

  2. If the truncation is inside a packet, fetch-pack will
     keep waiting for us to send the rest of the packet,
     which we never will.

  3. If the truncation is at a packet boundary, fetch-pack
     will keep waiting for us to send the next packet, which
     we never will.

As a result, fetch-pack hangs, waiting for input.  However,
remote-curl believes it has sent all of the advertisement,
and therefore waits for fetch-pack to speak. The two
processes end up in a deadlock.

We do notice the broken ref list if we feed it to
get_remote_heads. So if git asks the helper to do a "list"
followed by a "fetch", we are safe; we'll abort during the
list operation, which parses the refs.

This patch teaches remote-curl to always parse and save the
incoming ref list when we read the ref advertisement from a
server. That means that we will always verify and abort
before even running fetch-pack (or send-pack) when reading a
corrupted list, even if we do not run the "list" command
explicitly.

Since we save the result, in the common case of running
"list" then "fetch", we do not do any extra parsing at all.
In the case of just a "fetch", we do an extra round of
parsing, but only once.

Note also that the "fetch" case will now also initialize
server_capabilities from the remote (in remote-curl; we
already would do so inside fetch-pack).  Doing "list+fetch"
already does this. It doesn't actually matter now, but the
new behavior is arguably more correct, should remote-curl
ever start caring about the server's capability list.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 00:17:38 -08:00
Jeff King
b8054bbee7 remote-curl: move ref-parsing code up in file
The ref-parsing functions are static. Let's move them up in
the file to be available to more functions, which will help
us with later refactoring.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 00:17:38 -08:00
Jeff King
5dbf43602d remote-curl: pass buffer straight to get_remote_heads
Until recently, get_remote_heads only knew how to read refs
from a file descriptor. To hack around this, we spawned a
thread (or forked a process) to write the buffer back to us.

Now that we can just pass it our buffer directly, we don't
have to use this hack anymore.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 00:17:38 -08:00
Jeff King
85edf4f58b teach get_remote_heads to read from a memory buffer
Now that we can read packet data from memory as easily as a
descriptor, get_remote_heads can take either one as a
source. This will allow further refactoring in remote-curl.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 00:17:38 -08:00
Jeff King
4981fe750b pkt-line: share buffer/descriptor reading implementation
The packet_read function reads from a descriptor. The
packet_get_line function is similar, but reads from an
in-memory buffer, and uses a completely separate
implementation. This patch teaches the generic packet_read
function to accept either source, and we can do away with
packet_get_line's implementation.

There are two other differences to account for between the
old and new functions. The first is that we used to read
into a strbuf, but now read into a fixed size buffer. The
only two callers are fine with that, and in fact it
simplifies their code, since they can use the same
static-buffer interface as the rest of the packet_read_line
callers (and we provide a similar convenience wrapper for
reading from a buffer rather than a descriptor).

This is technically an externally-visible behavior change in
that we used to accept arbitrary sized packets up to 65532
bytes, and now cap out at LARGE_PACKET_MAX, 65520. In
practice this doesn't matter, as we use it only for parsing
smart-http headers (of which there is exactly one defined,
and it is small and fixed-size). And any extension headers
would be breaking the protocol to go over LARGE_PACKET_MAX
anyway.

The other difference is that packet_get_line would return
on error rather than dying. However, both callers of
packet_get_line are actually improved by dying.

The first caller does its own error checking, but we can
drop that; as a result, we'll actually get more specific
reporting about protocol breakage when packet_read dies
internally. The only downside is that packet_read will not
print the smart-http URL that failed, but that's not a big
deal; anybody not debugging can already see the remote's URL
already, and anybody debugging would want to run with
GIT_CURL_VERBOSE anyway to see way more information.

The second caller, which is just trying to skip past any
extra smart-http headers (of which there are none defined,
but which we allow to keep room for future expansion), did
not error check at all. As a result, it would treat an error
just like a flush packet. The resulting mess would generally
cause an error later in get_remote_heads, but now we get
error reporting much closer to the source of the problem.

Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 00:14:15 -08:00
Jeff King
819b929d33 pkt-line: teach packet_read_line to chomp newlines
The packets sent during ref negotiation are all terminated
by newline; even though the code to chomp these newlines is
short, we end up doing it in a lot of places.

This patch teaches packet_read_line to auto-chomp the
trailing newline; this lets us get rid of a lot of inline
chomping code.

As a result, some call-sites which are not reading
line-oriented data (e.g., when reading chunks of packfiles
alongside sideband) transition away from packet_read_line to
the generic packet_read interface. This patch converts all
of the existing callsites.

Since the function signature of packet_read_line does not
change (but its behavior does), there is a possibility of
new callsites being introduced in later commits, silently
introducing an incompatibility.  However, since a later
patch in this series will change the signature, such a
commit would have to be merged directly into this commit,
not to the tip of the series; we can therefore ignore the
issue.

This is an internal cleanup and should produce no change of
behavior in the normal case. However, there is one corner
case to note. Callers of packet_read_line have never been
able to tell the difference between a flush packet ("0000")
and an empty packet ("0004"), as both cause packet_read_line
to return a length of 0. Readers treat them identically,
even though Documentation/technical/protocol-common.txt says
we must not; it also says that implementations should not
send an empty pkt-line.

By stripping out the newline before the result gets to the
caller, we will now treat the newline-only packet ("0005\n")
the same as an empty packet, which in turn gets treated like
a flush packet. In practice this doesn't matter, as neither
empty nor newline-only packets are part of git's protocols
(at least not for the line-oriented bits, and readers who
are not expecting line-oriented packets will be calling
packet_read directly, anyway). But even if we do decide to
care about the distinction later, it is orthogonal to this
patch.  The right place to tighten would be to stop treating
empty packets as flush packets, and this change does not
make doing so any harder.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 13:42:21 -08:00
Jeff King
cdf4fb8e33 pkt-line: drop safe_write function
This is just write_or_die by another name. The one
distinction is that write_or_die will treat EPIPE specially
by suppressing error messages. That's fine, as we die by
SIGPIPE anyway (and in the off chance that it is disabled,
write_or_die will simulate it).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 13:42:21 -08:00
Shawn Pearce
4656bf47fc Verify Content-Type from smart HTTP servers
Before parsing a suspected smart-HTTP response verify the returned
Content-Type matches the standard. This protects a client from
attempting to process a payload that smells like a smart-HTTP
server response.

JGit has been doing this check on all responses since the dawn of
time. I mistakenly failed to include it in git-core when smart HTTP
was introduced. At the time I didn't know how to get the Content-Type
from libcurl. I punted, meant to circle back and fix this, and just
plain forgot about it.

Signed-off-by: Shawn Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-04 10:22:36 -08:00
Junio C Hamano
fda800f0b1 Merge branch 'jk/maint-http-half-auth-fetch'
Finishing touches to squelch a compiler warning.

* jk/maint-http-half-auth-fetch:
  remote-curl.c: Fix a compiler warning
2012-11-21 11:59:29 -08:00
Ramsay Jones
377115493a remote-curl.c: Fix a compiler warning
In particular, gcc issues an "'gzip_size' might be used uninitialized"
warning (-Wuninitialized). However, this warning is a false positive,
since the 'gzip_size' variable would not, in fact, be used uninitialized.
In order to suppress the warning, we simply initialise the variable to
zero in it's declaration.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-11-21 11:54:32 -08:00
Junio C Hamano
a9bb4e55a3 Merge branch 'jk/maint-http-half-auth-fetch'
Fixes fetch from servers that ask for auth only during the actual
packing phase. This is not really a recommended configuration, but it
cleans up the code at the same time.

* jk/maint-http-half-auth-fetch:
  remote-curl: retry failed requests for auth even with gzip
  remote-curl: hoist gzip buffer size to top of post_rpc
2012-11-20 10:30:17 -08:00
Jeff King
2e736fd5e9 remote-curl: retry failed requests for auth even with gzip
Commit b81401c taught the post_rpc function to retry the
http request after prompting for credentials. However, it
did not handle two cases:

  1. If we have a large request, we do not retry. That's OK,
     since we would have sent a probe (with retry) already.

  2. If we are gzipping the request, we do not retry. That
     was considered OK, because the intended use was for
     push (e.g., listing refs is OK, but actually pushing
     objects is not), and we never gzip on push.

This patch teaches post_rpc to retry even a gzipped request.
This has two advantages:

  1. It is possible to configure a "half-auth" state for
     fetching, where the set of refs and their sha1s are
     advertised, but one cannot actually fetch objects.

     This is not a recommended configuration, as it leaks
     some information about what is in the repository (e.g.,
     an attacker can try brute-forcing possible content in
     your repository and checking whether it matches your
     branch sha1). However, it can be slightly more
     convenient, since a no-op fetch will not require a
     password at all.

  2. It future-proofs us should we decide to ever gzip more
     requests.

Signed-off-by: Jeff King <peff@peff.net>
2012-10-31 07:45:13 -04:00
Jeff King
df126e108b remote-curl: hoist gzip buffer size to top of post_rpc
When we gzip the post data for a smart-http rpc request, we
compute the gzip body and its size inside the "use_gzip"
conditional. We keep track of the body after the conditional
ends, but not the size. Let's remember both, which will
enable us to retry failed gzip requests in a future patch.

Signed-off-by: Jeff King <peff@peff.net>
2012-10-31 07:45:08 -04:00
Jeff King
58f3f9893d Merge branch 'jk/maint-http-init-not-in-result-handler'
Further clean-up to the http codepath that picks up results after
cURL library is done with one request slot.

* jk/maint-http-init-not-in-result-handler:
  http: do not set up curl auth after a 401
  remote-curl: do not call run_slot repeatedly
2012-10-29 04:13:09 -04:00
Junio C Hamano
053a08f5bb Merge branch 'jk/maint-http-half-auth-push'
Fixes a regression in maint-1.7.11 (v1.7.11.7), maint (v1.7.12.1)
and master (v1.8.0-rc0).

* jk/maint-http-half-auth-push:
  http: fix segfault in handle_curl_result
2012-10-16 11:44:37 -07:00
Jeff King
1960897ebc http: do not set up curl auth after a 401
When we get an http 401, we prompt for credentials and put
them in our global credential struct. We also feed them to
the curl handle that produced the 401, with the intent that
they will be used on a retry.

When the code was originally introduced in commit 42653c0,
this was a necessary step. However, since dfa1725, we always
feed our global credential into every curl handle when we
initialize the slot with get_active_slot. So every further
request already feeds the credential to curl.

Moreover, accessing the slot here is somewhat dubious. After
the slot has produced a response, we don't actually control
it any more.  If we are using curl_multi, it may even have
been re-initialized to handle a different request.

It just so happens that we will reuse the curl handle within
the slot in such a case, and that because we only keep one
global credential, it will be the one we want.  So the
current code is not buggy, but it is misleading.

By cleaning it up, we can remove the slot argument entirely
from handle_curl_result, making it much more obvious that
slots should not be accessed after they are marked as
finished.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-12 09:45:15 -07:00
Jeff King
abf8df869c remote-curl: do not call run_slot repeatedly
Commit b81401c (http: prompt for credentials on failed POST)
taught post_rpc to call run_slot in a loop in order to retry
a request after asking the user for credentials. However,
after a call to run_slot we will have called
finish_active_slot. This means we have released the slot,
and we should no longer look at it.

As it happens, this does not cause any bugs in the current
code, since we know that we are not using curl_multi in this
code path, and therefore nobody will have taken over our
slot in the meantime. However, it is good form to actually
call get_active_slot again. It also future proofs us against
changes in the http code.

We can do this by jumping back to a retry label at the top
of our function. We just need to reorder a few setup lines
that should not be repeated; everything else within the loop
is either idempotent, needs to be repeated, or in a path we
do not follow (e.g., we do not even try when large_request
is set, because we don't know how much data we might have
streamed from our helper program).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-12 09:45:13 -07:00
Jeff King
188923f0d1 http: fix segfault in handle_curl_result
When we create an http active_request_slot, we can set its
"results" pointer back to local storage. The http code will
fill in the details of how the request went, and we can
access those details even after the slot has been cleaned
up.

Commit 8809703 (http: factor out http error code handling)
switched us from accessing our local results struct directly
to accessing it via the "results" pointer of the slot. That
means we're accessing the slot after it has been marked as
finished, defeating the whole purpose of keeping the results
storage separate.

Most of the time this doesn't matter, as finishing the slot
does not actually clean up the pointer. However, when using
curl's multi interface with the dumb-http revision walker,
we might actually start a new request before handing control
back to the original caller. In that case, we may reuse the
slot, zeroing its results pointer, and leading the original
caller to segfault while looking for its results inside the
slot.

Instead, we need to pass a pointer to our local results
storage to the handle_curl_result function, rather than
relying on the pointer in the slot struct. This matches what
the original code did before the refactoring (which did not
use a separate function, and therefore just accessed the
results struct directly).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-12 09:42:31 -07:00
Junio C Hamano
fb1e4a85bf Merge branch 'jk/smart-http-switch'
Allows users to turn off smart-http when talking to dumb-only
servers.

* jk/smart-http-switch:
  remote-curl: let users turn off smart http
  remote-curl: rename is_http variable
2012-09-29 22:28:25 -07:00
Junio C Hamano
c318040a36 Merge branch 'sp/maint-http-enable-gzip'
Allows a more common 'gzip' Accept-Encoding to be used.

* sp/maint-http-enable-gzip:
  Enable info/refs gzip decompression in HTTP client
2012-09-29 22:28:20 -07:00
Jeff King
02572c2e3a remote-curl: let users turn off smart http
Usually there is no need for users to specify whether an
http remote is smart or dumb; the protocol is designed so
that a single initial request is made, and the client can
determine the server's capability from the response.

However, some misconfigured dumb-only servers may not like
the initial request by a smart client, as it contains a
query string. Until recently, commit 703e6e7 worked around
this by making a second request. However, that commit was
recently reverted due to its side effect of masking the
initial request's error code.

Since git has had that workaround for several years, we
don't know exactly how many such misconfigured servers are
out there. The reversion of 703e6e7 assumes they are rare
enough not to worry about. Still, that reversion leaves
somebody who does run into such a server with no escape
hatch at all. Let's give them an environment variable they
can tweak to perform the "dumb" request.

This is intentionally not a documented interface. It's
overly simple and is really there for debugging in case
somebody does complain about git not working with their
server. A real user-facing interface would entail a
per-remote or per-URL config variable.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-21 10:33:11 -07:00
Jeff King
243c329c1e remote-curl: rename is_http variable
We don't actually care whether the connection is http or
not; what we care about is whether it might be smart http.
Rename the variable to be more accurate, which will make it
easier to later make smart-http optional.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-20 10:48:45 -07:00