git/http.h
Jeff King c93c92f309 http: update base URLs when we see redirects
If a caller asks the http_get_* functions to go to a
particular URL and we end up elsewhere due to a redirect,
the effective_url field can tell us where we went.

It would be nice to remember this redirect and short-cut
further requests for two reasons:

  1. It's more efficient. Otherwise we spend an extra http
     round-trip to the server for each subsequent request,
     just to get redirected.

  2. If we end up with an http 401 and are going to ask for
     credentials, it is to feed them to the redirect target.
     If the redirect is an http->https upgrade, this means
     our credentials may be provided on the http leg, just
     to end up redirected to https. And if the redirect
     crosses server boundaries, then curl will drop the
     credentials entirely as it follows the redirect.

However, it, it is not enough to simply record the effective
URL we saw and use that for subsequent requests. We were
originally fed a "base" url like:

   http://example.com/foo.git

and we want to figure out what the new base is, even though
the URLs we see may be:

     original: http://example.com/foo.git/info/refs
    effective: http://example.com/bar.git/info/refs

Subsequent requests will not be for "info/refs", but for
other paths relative to the base. We must ask the caller to
pass in the original base, and we must pass the redirected
base back to the caller (so that it can generate more URLs
from it). Furthermore, we need to feed the new base to the
credential code, so that requests to credential helpers (or
to the user) match the URL we will be requesting.

This patch teaches http_request_reauth to do this munging.
Since it is the caller who cares about making more URLs, it
seems at first glance that callers could simply check
effective_url themselves and handle it. However, since we
need to update the credential struct before the second
re-auth request, we have to do it inside http_request_reauth.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 16:56:47 -07:00

213 lines
5.8 KiB
C

#ifndef HTTP_H
#define HTTP_H
#include "cache.h"
#include <curl/curl.h>
#include <curl/easy.h>
#include "strbuf.h"
#include "remote.h"
#include "url.h"
/*
* We detect based on the cURL version if multi-transfer is
* usable in this implementation and define this symbol accordingly.
* This is not something Makefile should set nor users should pass
* via CFLAGS.
*/
#undef USE_CURL_MULTI
#if LIBCURL_VERSION_NUM >= 0x071000
#define USE_CURL_MULTI
#define DEFAULT_MAX_REQUESTS 5
#endif
#if LIBCURL_VERSION_NUM < 0x070704
#define curl_global_cleanup() do { /* nothing */ } while (0)
#endif
#if LIBCURL_VERSION_NUM < 0x070800
#define curl_global_init(a) do { /* nothing */ } while (0)
#endif
#if (LIBCURL_VERSION_NUM < 0x070c04) || (LIBCURL_VERSION_NUM == 0x071000)
#define NO_CURL_EASY_DUPHANDLE
#endif
#if LIBCURL_VERSION_NUM < 0x070a03
#define CURLE_HTTP_RETURNED_ERROR CURLE_HTTP_NOT_FOUND
#endif
#if LIBCURL_VERSION_NUM < 0x070c03
#define NO_CURL_IOCTL
#endif
/*
* CURLOPT_USE_SSL was known as CURLOPT_FTP_SSL up to 7.16.4,
* and the constants were known as CURLFTPSSL_*
*/
#if !defined(CURLOPT_USE_SSL) && defined(CURLOPT_FTP_SSL)
#define CURLOPT_USE_SSL CURLOPT_FTP_SSL
#define CURLUSESSL_TRY CURLFTPSSL_TRY
#endif
struct slot_results {
CURLcode curl_result;
long http_code;
};
struct active_request_slot {
CURL *curl;
int in_use;
CURLcode curl_result;
long http_code;
int *finished;
struct slot_results *results;
void *callback_data;
void (*callback_func)(void *data);
struct active_request_slot *next;
};
struct buffer {
struct strbuf buf;
size_t posn;
};
/* Curl request read/write callbacks */
extern size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
#ifndef NO_CURL_IOCTL
extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
#endif
/* Slot lifecycle functions */
extern struct active_request_slot *get_active_slot(void);
extern int start_active_slot(struct active_request_slot *slot);
extern void run_active_slot(struct active_request_slot *slot);
extern void finish_active_slot(struct active_request_slot *slot);
extern void finish_all_active_slots(void);
extern int handle_curl_result(struct slot_results *results);
#ifdef USE_CURL_MULTI
extern void fill_active_slots(void);
extern void add_fill_function(void *data, int (*fill)(void *));
extern void step_active_slots(void);
#endif
extern void http_init(struct remote *remote, const char *url,
int proactive_auth);
extern void http_cleanup(void);
extern int active_requests;
extern int http_is_verbose;
extern size_t http_post_buffer;
extern struct credential http_auth;
extern char curl_errorstr[CURL_ERROR_SIZE];
static inline int missing__target(int code, int result)
{
return /* file:// URL -- do we ever use one??? */
(result == CURLE_FILE_COULDNT_READ_FILE) ||
/* http:// and https:// URL */
(code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
/* ftp:// URL */
(code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
;
}
#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
/* Helpers for modifying and creating URLs */
extern void append_remote_object_url(struct strbuf *buf, const char *url,
const char *hex,
int only_two_digit_prefix);
extern char *get_remote_object_url(const char *url, const char *hex,
int only_two_digit_prefix);
/* Options for http_get_*() */
struct http_get_options {
unsigned no_cache:1,
keep_error:1;
/* If non-NULL, returns the content-type of the response. */
struct strbuf *content_type;
/*
* If non-NULL, returns the URL we ended up at, including any
* redirects we followed.
*/
struct strbuf *effective_url;
/*
* If both base_url and effective_url are non-NULL, the base URL will
* be munged to reflect any redirections going from the requested url
* to effective_url. See the definition of update_url_from_redirect
* for details.
*/
struct strbuf *base_url;
};
/* Return values for http_get_*() */
#define HTTP_OK 0
#define HTTP_MISSING_TARGET 1
#define HTTP_ERROR 2
#define HTTP_START_FAILED 3
#define HTTP_REAUTH 4
#define HTTP_NOAUTH 5
/*
* Requests a URL and stores the result in a strbuf.
*
* If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
*/
int http_get_strbuf(const char *url, struct strbuf *result, struct http_get_options *options);
extern int http_fetch_ref(const char *base, struct ref *ref);
/* Helpers for fetching packs */
extern int http_get_info_packs(const char *base_url,
struct packed_git **packs_head);
struct http_pack_request {
char *url;
struct packed_git *target;
struct packed_git **lst;
FILE *packfile;
char tmpfile[PATH_MAX];
struct curl_slist *range_header;
struct active_request_slot *slot;
};
extern struct http_pack_request *new_http_pack_request(
struct packed_git *target, const char *base_url);
extern int finish_http_pack_request(struct http_pack_request *preq);
extern void release_http_pack_request(struct http_pack_request *preq);
/* Helpers for fetching object */
struct http_object_request {
char *url;
char tmpfile[PATH_MAX];
int localfile;
CURLcode curl_result;
char errorstr[CURL_ERROR_SIZE];
long http_code;
unsigned char sha1[20];
unsigned char real_sha1[20];
git_SHA_CTX c;
git_zstream stream;
int zret;
int rename;
struct active_request_slot *slot;
};
extern struct http_object_request *new_http_object_request(
const char *base_url, unsigned char *sha1);
extern void process_http_object_request(struct http_object_request *freq);
extern int finish_http_object_request(struct http_object_request *freq);
extern void abort_http_object_request(struct http_object_request *freq);
extern void release_http_object_request(struct http_object_request *freq);
#endif /* HTTP_H */