Initial commit for TizenHEADsubmit/2.0alpha/20130201.014617accepted/2.0alpha/20130201.0121062.0alpha

1 files changed, 1383 insertions, 0 deletions

diff --git a/http.c b/http.c
new file mode 100644
index 0000000..1320c50
--- /dev/null
+++ b/http.c
@@ -0,0 +1,1383 @@
+#include "http.h"
+#include "pack.h"
+#include "sideband.h"
+#include "run-command.h"
+
+int data_received;
+int active_requests;
+int http_is_verbose;
+size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
+
+#if LIBCURL_VERSION_NUM >= 0x070a06
+#define LIBCURL_CAN_HANDLE_AUTH_ANY
+#endif
+
+static int min_curl_sessions = 1;
+static int curl_session_count;
+#ifdef USE_CURL_MULTI
+static int max_requests = -1;
+static CURLM *curlm;
+#endif
+#ifndef NO_CURL_EASY_DUPHANDLE
+static CURL *curl_default;
+#endif
+
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
+
+char curl_errorstr[CURL_ERROR_SIZE];
+
+static int curl_ssl_verify = -1;
+static const char *ssl_cert;
+#if LIBCURL_VERSION_NUM >= 0x070903
+static const char *ssl_key;
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+static const char *ssl_capath;
+#endif
+static const char *ssl_cainfo;
+static long curl_low_speed_limit = -1;
+static long curl_low_speed_time = -1;
+static int curl_ftp_no_epsv;
+static const char *curl_http_proxy;
+static char *user_name, *user_pass;
+
+#if LIBCURL_VERSION_NUM >= 0x071700
+/* Use CURLOPT_KEYPASSWD as is */
+#elif LIBCURL_VERSION_NUM >= 0x070903
+#define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
+#else
+#define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
+#endif
+
+static char *ssl_cert_password;
+static int ssl_cert_password_required;
+
+static struct curl_slist *pragma_header;
+static struct curl_slist *no_pragma_header;
+
+static struct active_request_slot *active_queue_head;
+
+size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
+{
+	size_t size = eltsize * nmemb;
+	struct buffer *buffer = buffer_;
+
+	if (size > buffer->buf.len - buffer->posn)
+		size = buffer->buf.len - buffer->posn;
+	memcpy(ptr, buffer->buf.buf + buffer->posn, size);
+	buffer->posn += size;
+
+	return size;
+}
+
+#ifndef NO_CURL_IOCTL
+curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
+{
+	struct buffer *buffer = clientp;
+
+	switch (cmd) {
+	case CURLIOCMD_NOP:
+		return CURLIOE_OK;
+
+	case CURLIOCMD_RESTARTREAD:
+		buffer->posn = 0;
+		return CURLIOE_OK;
+
+	default:
+		return CURLIOE_UNKNOWNCMD;
+	}
+}
+#endif
+
+size_t fwrite_buffer(const void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
+{
+	size_t size = eltsize * nmemb;
+	struct strbuf *buffer = buffer_;
+
+	strbuf_add(buffer, ptr, size);
+	data_received++;
+	return size;
+}
+
+size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf)
+{
+	data_received++;
+	return eltsize * nmemb;
+}
+
+#ifdef USE_CURL_MULTI
+static void process_curl_messages(void)
+{
+	int num_messages;
+	struct active_request_slot *slot;
+	CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
+
+	while (curl_message != NULL) {
+		if (curl_message->msg == CURLMSG_DONE) {
+			int curl_result = curl_message->data.result;
+			slot = active_queue_head;
+			while (slot != NULL &&
+			       slot->curl != curl_message->easy_handle)
+				slot = slot->next;
+			if (slot != NULL) {
+				curl_multi_remove_handle(curlm, slot->curl);
+				slot->curl_result = curl_result;
+				finish_active_slot(slot);
+			} else {
+				fprintf(stderr, "Received DONE message for unknown request!\n");
+			}
+		} else {
+			fprintf(stderr, "Unknown CURL message received: %d\n",
+				(int)curl_message->msg);
+		}
+		curl_message = curl_multi_info_read(curlm, &num_messages);
+	}
+}
+#endif
+
+static int http_options(const char *var, const char *value, void *cb)
+{
+	if (!strcmp("http.sslverify", var)) {
+		curl_ssl_verify = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp("http.sslcert", var))
+		return git_config_string(&ssl_cert, var, value);
+#if LIBCURL_VERSION_NUM >= 0x070903
+	if (!strcmp("http.sslkey", var))
+		return git_config_string(&ssl_key, var, value);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (!strcmp("http.sslcapath", var))
+		return git_config_string(&ssl_capath, var, value);
+#endif
+	if (!strcmp("http.sslcainfo", var))
+		return git_config_string(&ssl_cainfo, var, value);
+	if (!strcmp("http.sslcertpasswordprotected", var)) {
+		if (git_config_bool(var, value))
+			ssl_cert_password_required = 1;
+		return 0;
+	}
+	if (!strcmp("http.minsessions", var)) {
+		min_curl_sessions = git_config_int(var, value);
+#ifndef USE_CURL_MULTI
+		if (min_curl_sessions > 1)
+			min_curl_sessions = 1;
+#endif
+		return 0;
+	}
+#ifdef USE_CURL_MULTI
+	if (!strcmp("http.maxrequests", var)) {
+		max_requests = git_config_int(var, value);
+		return 0;
+	}
+#endif
+	if (!strcmp("http.lowspeedlimit", var)) {
+		curl_low_speed_limit = (long)git_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp("http.lowspeedtime", var)) {
+		curl_low_speed_time = (long)git_config_int(var, value);
+		return 0;
+	}
+
+	if (!strcmp("http.noepsv", var)) {
+		curl_ftp_no_epsv = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp("http.proxy", var))
+		return git_config_string(&curl_http_proxy, var, value);
+
+	if (!strcmp("http.postbuffer", var)) {
+		http_post_buffer = git_config_int(var, value);
+		if (http_post_buffer < LARGE_PACKET_MAX)
+			http_post_buffer = LARGE_PACKET_MAX;
+		return 0;
+	}
+
+	/* Fall back on the default ones */
+	return git_default_config(var, value, cb);
+}
+
+static void init_curl_http_auth(CURL *result)
+{
+	if (user_name) {
+		struct strbuf up = STRBUF_INIT;
+		if (!user_pass)
+			user_pass = xstrdup(git_getpass("Password: "));
+		strbuf_addf(&up, "%s:%s", user_name, user_pass);
+		curl_easy_setopt(result, CURLOPT_USERPWD,
+				 strbuf_detach(&up, NULL));
+	}
+}
+
+static int has_cert_password(void)
+{
+	if (ssl_cert_password != NULL)
+		return 1;
+	if (ssl_cert == NULL || ssl_cert_password_required != 1)
+		return 0;
+	/* Only prompt the user once. */
+	ssl_cert_password_required = -1;
+	ssl_cert_password = git_getpass("Certificate Password: ");
+	if (ssl_cert_password != NULL) {
+		ssl_cert_password = xstrdup(ssl_cert_password);
+		return 1;
+	} else
+		return 0;
+}
+
+static CURL *get_curl_handle(void)
+{
+	CURL *result = curl_easy_init();
+
+	if (!curl_ssl_verify) {
+		curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
+		curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
+	} else {
+		/* Verify authenticity of the peer's certificate */
+		curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
+		/* The name in the cert must match whom we tried to connect */
+		curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
+	}
+
+#if LIBCURL_VERSION_NUM >= 0x070907
+	curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
+#endif
+#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
+	curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
+#endif
+
+	init_curl_http_auth(result);
+
+	if (ssl_cert != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
+	if (has_cert_password())
+		curl_easy_setopt(result, CURLOPT_KEYPASSWD, ssl_cert_password);
+#if LIBCURL_VERSION_NUM >= 0x070903
+	if (ssl_key != NULL)
+		curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	if (ssl_capath != NULL)
+		curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
+#endif
+	if (ssl_cainfo != NULL)
+		curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
+	curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
+
+	if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
+				 curl_low_speed_limit);
+		curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
+				 curl_low_speed_time);
+	}
+
+	curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
+
+	if (getenv("GIT_CURL_VERBOSE"))
+		curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
+
+	curl_easy_setopt(result, CURLOPT_USERAGENT, GIT_USER_AGENT);
+
+	if (curl_ftp_no_epsv)
+		curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
+
+	if (curl_http_proxy)
+		curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
+
+	return result;
+}
+
+static void http_auth_init(const char *url)
+{
+	char *at, *colon, *cp, *slash;
+	int len;
+
+	cp = strstr(url, "://");
+	if (!cp)
+		return;
+
+	/*
+	 * Ok, the URL looks like "proto://something".  Which one?
+	 * "proto://<user>:<pass>@<host>/...",
+	 * "proto://<user>@<host>/...", or just
+	 * "proto://<host>/..."?
+	 */
+	cp += 3;
+	at = strchr(cp, '@');
+	colon = strchr(cp, ':');
+	slash = strchrnul(cp, '/');
+	if (!at || slash <= at)
+		return; /* No credentials */
+	if (!colon || at <= colon) {
+		/* Only username */
+		len = at - cp;
+		user_name = xmalloc(len + 1);
+		memcpy(user_name, cp, len);
+		user_name[len] = '\0';
+		user_pass = NULL;
+	} else {
+		len = colon - cp;
+		user_name = xmalloc(len + 1);
+		memcpy(user_name, cp, len);
+		user_name[len] = '\0';
+		len = at - (colon + 1);
+		user_pass = xmalloc(len + 1);
+		memcpy(user_pass, colon + 1, len);
+		user_pass[len] = '\0';
+	}
+}
+
+static void set_from_env(const char **var, const char *envname)
+{
+	const char *val = getenv(envname);
+	if (val)
+		*var = val;
+}
+
+void http_init(struct remote *remote)
+{
+	char *low_speed_limit;
+	char *low_speed_time;
+
+	http_is_verbose = 0;
+
+	git_config(http_options, NULL);
+
+	curl_global_init(CURL_GLOBAL_ALL);
+
+	if (remote && remote->http_proxy)
+		curl_http_proxy = xstrdup(remote->http_proxy);
+
+	pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
+	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
+
+#ifdef USE_CURL_MULTI
+	{
+		char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
+		if (http_max_requests != NULL)
+			max_requests = atoi(http_max_requests);
+	}
+
+	curlm = curl_multi_init();
+	if (curlm == NULL) {
+		fprintf(stderr, "Error creating curl multi handle.\n");
+		exit(1);
+	}
+#endif
+
+	if (getenv("GIT_SSL_NO_VERIFY"))
+		curl_ssl_verify = 0;
+
+	set_from_env(&ssl_cert, "GIT_SSL_CERT");
+#if LIBCURL_VERSION_NUM >= 0x070903
+	set_from_env(&ssl_key, "GIT_SSL_KEY");
+#endif
+#if LIBCURL_VERSION_NUM >= 0x070908
+	set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
+#endif
+	set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
+
+	low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
+	if (low_speed_limit != NULL)
+		curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
+	low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
+	if (low_speed_time != NULL)
+		curl_low_speed_time = strtol(low_speed_time, NULL, 10);
+
+	if (curl_ssl_verify == -1)
+		curl_ssl_verify = 1;
+
+	curl_session_count = 0;
+#ifdef USE_CURL_MULTI
+	if (max_requests < 1)
+		max_requests = DEFAULT_MAX_REQUESTS;
+#endif
+
+	if (getenv("GIT_CURL_FTP_NO_EPSV"))
+		curl_ftp_no_epsv = 1;
+
+	if (remote && remote->url && remote->url[0]) {
+		http_auth_init(remote->url[0]);
+		if (!ssl_cert_password_required &&
+		    getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
+		    !prefixcmp(remote->url[0], "https://"))
+			ssl_cert_password_required = 1;
+	}
+
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_default = get_curl_handle();
+#endif
+}
+
+void http_cleanup(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+
+	while (slot != NULL) {
+		struct active_request_slot *next = slot->next;
+		if (slot->curl != NULL) {
+#ifdef USE_CURL_MULTI
+			curl_multi_remove_handle(curlm, slot->curl);
+#endif
+			curl_easy_cleanup(slot->curl);
+		}
+		free(slot);
+		slot = next;
+	}
+	active_queue_head = NULL;
+
+#ifndef NO_CURL_EASY_DUPHANDLE
+	curl_easy_cleanup(curl_default);
+#endif
+
+#ifdef USE_CURL_MULTI
+	curl_multi_cleanup(curlm);
+#endif
+	curl_global_cleanup();
+
+	curl_slist_free_all(pragma_header);
+	pragma_header = NULL;
+
+	curl_slist_free_all(no_pragma_header);
+	no_pragma_header = NULL;
+
+	if (curl_http_proxy) {
+		free((void *)curl_http_proxy);
+		curl_http_proxy = NULL;
+	}
+
+	if (ssl_cert_password != NULL) {
+		memset(ssl_cert_password, 0, strlen(ssl_cert_password));
+		free(ssl_cert_password);
+		ssl_cert_password = NULL;
+	}
+	ssl_cert_password_required = 0;
+}
+
+struct active_request_slot *get_active_slot(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+	struct active_request_slot *newslot;
+
+#ifdef USE_CURL_MULTI
+	int num_transfers;
+
+	/* Wait for a slot to open up if the queue is full */
+	while (active_requests >= max_requests) {
+		curl_multi_perform(curlm, &num_transfers);
+		if (num_transfers < active_requests)
+			process_curl_messages();
+	}
+#endif
+
+	while (slot != NULL && slot->in_use)
+		slot = slot->next;
+
+	if (slot == NULL) {
+		newslot = xmalloc(sizeof(*newslot));
+		newslot->curl = NULL;
+		newslot->in_use = 0;
+		newslot->next = NULL;
+
+		slot = active_queue_head;
+		if (slot == NULL) {
+			active_queue_head = newslot;
+		} else {
+			while (slot->next != NULL)
+				slot = slot->next;
+			slot->next = newslot;
+		}
+		slot = newslot;
+	}
+
+	if (slot->curl == NULL) {
+#ifdef NO_CURL_EASY_DUPHANDLE
+		slot->curl = get_curl_handle();
+#else
+		slot->curl = curl_easy_duphandle(curl_default);
+#endif
+		curl_session_count++;
+	}
+
+	active_requests++;
+	slot->in_use = 1;
+	slot->local = NULL;
+	slot->results = NULL;
+	slot->finished = NULL;
+	slot->callback_data = NULL;
+	slot->callback_func = NULL;
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
+	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
+	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
+	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+
+	return slot;
+}
+
+int start_active_slot(struct active_request_slot *slot)
+{
+#ifdef USE_CURL_MULTI
+	CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
+	int num_transfers;
+
+	if (curlm_result != CURLM_OK &&
+	    curlm_result != CURLM_CALL_MULTI_PERFORM) {
+		active_requests--;
+		slot->in_use = 0;
+		return 0;
+	}
+
+	/*
+	 * We know there must be something to do, since we just added
+	 * something.
+	 */
+	curl_multi_perform(curlm, &num_transfers);
+#endif
+	return 1;
+}
+
+#ifdef USE_CURL_MULTI
+struct fill_chain {
+	void *data;
+	int (*fill)(void *);
+	struct fill_chain *next;
+};
+
+static struct fill_chain *fill_cfg;
+
+void add_fill_function(void *data, int (*fill)(void *))
+{
+	struct fill_chain *new = xmalloc(sizeof(*new));
+	struct fill_chain **linkp = &fill_cfg;
+	new->data = data;
+	new->fill = fill;
+	new->next = NULL;
+	while (*linkp)
+		linkp = &(*linkp)->next;
+	*linkp = new;
+}
+
+void fill_active_slots(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+
+	while (active_requests < max_requests) {
+		struct fill_chain *fill;
+		for (fill = fill_cfg; fill; fill = fill->next)
+			if (fill->fill(fill->data))
+				break;
+
+		if (!fill)
+			break;
+	}
+
+	while (slot != NULL) {
+		if (!slot->in_use && slot->curl != NULL
+			&& curl_session_count > min_curl_sessions) {
+			curl_easy_cleanup(slot->curl);
+			slot->curl = NULL;
+			curl_session_count--;
+		}
+		slot = slot->next;
+	}
+}
+
+void step_active_slots(void)
+{
+	int num_transfers;
+	CURLMcode curlm_result;
+
+	do {
+		curlm_result = curl_multi_perform(curlm, &num_transfers);
+	} while (curlm_result == CURLM_CALL_MULTI_PERFORM);
+	if (num_transfers < active_requests) {
+		process_curl_messages();
+		fill_active_slots();
+	}
+}
+#endif
+
+void run_active_slot(struct active_request_slot *slot)
+{
+#ifdef USE_CURL_MULTI
+	long last_pos = 0;
+	long current_pos;
+	fd_set readfds;
+	fd_set writefds;
+	fd_set excfds;
+	int max_fd;
+	struct timeval select_timeout;
+	int finished = 0;
+
+	slot->finished = &finished;
+	while (!finished) {
+		data_received = 0;
+		step_active_slots();
+
+		if (!data_received && slot->local != NULL) {
+			current_pos = ftell(slot->local);
+			if (current_pos > last_pos)
+				data_received++;
+			last_pos = current_pos;
+		}
+
+		if (slot->in_use && !data_received) {
+			max_fd = 0;
+			FD_ZERO(&readfds);
+			FD_ZERO(&writefds);
+			FD_ZERO(&excfds);
+			select_timeout.tv_sec = 0;
+			select_timeout.tv_usec = 50000;
+			select(max_fd, &readfds, &writefds,
+			       &excfds, &select_timeout);
+		}
+	}
+#else
+	while (slot->in_use) {
+		slot->curl_result = curl_easy_perform(slot->curl);
+		finish_active_slot(slot);
+	}
+#endif
+}
+
+static void closedown_active_slot(struct active_request_slot *slot)
+{
+	active_requests--;
+	slot->in_use = 0;
+}
+
+static void release_active_slot(struct active_request_slot *slot)
+{
+	closedown_active_slot(slot);
+	if (slot->curl && curl_session_count > min_curl_sessions) {
+#ifdef USE_CURL_MULTI
+		curl_multi_remove_handle(curlm, slot->curl);
+#endif
+		curl_easy_cleanup(slot->curl);
+		slot->curl = NULL;
+		curl_session_count--;
+	}
+#ifdef USE_CURL_MULTI
+	fill_active_slots();
+#endif
+}
+
+void finish_active_slot(struct active_request_slot *slot)
+{
+	closedown_active_slot(slot);
+	curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
+
+	if (slot->finished != NULL)
+		(*slot->finished) = 1;
+
+	/* Store slot results so they can be read after the slot is reused */
+	if (slot->results != NULL) {
+		slot->results->curl_result = slot->curl_result;
+		slot->results->http_code = slot->http_code;
+	}
+
+	/* Run callback if appropriate */
+	if (slot->callback_func != NULL)
+		slot->callback_func(slot->callback_data);
+}
+
+void finish_all_active_slots(void)
+{
+	struct active_request_slot *slot = active_queue_head;
+
+	while (slot != NULL)
+		if (slot->in_use) {
+			run_active_slot(slot);
+			slot = active_queue_head;
+		} else {
+			slot = slot->next;
+		}
+}
+
+/* Helpers for modifying and creating URLs */
+static inline int needs_quote(int ch)
+{
+	if (((ch >= 'A') && (ch <= 'Z'))
+			|| ((ch >= 'a') && (ch <= 'z'))
+			|| ((ch >= '0') && (ch <= '9'))
+			|| (ch == '/')
+			|| (ch == '-')
+			|| (ch == '.'))
+		return 0;
+	return 1;
+}
+
+static inline int hex(int v)
+{
+	if (v < 10)
+		return '0' + v;
+	else
+		return 'A' + v - 10;
+}
+
+void end_url_with_slash(struct strbuf *buf, const char *url)
+{
+	strbuf_addstr(buf, url);
+	if (buf->len && buf->buf[buf->len - 1] != '/')
+		strbuf_addstr(buf, "/");
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+	struct strbuf buf = STRBUF_INIT;
+	const char *cp;
+	int ch;
+
+	end_url_with_slash(&buf, base);
+
+	for (cp = ref; (ch = *cp) != 0; cp++)
+		if (needs_quote(ch))
+			strbuf_addf(&buf, "%%%02x", ch);
+		else
+			strbuf_addch(&buf, *cp);
+
+	return strbuf_detach(&buf, NULL);
+}
+
+void append_remote_object_url(struct strbuf *buf, const char *url,
+			      const char *hex,
+			      int only_two_digit_prefix)
+{
+	end_url_with_slash(buf, url);
+
+	strbuf_addf(buf, "objects/%.*s/", 2, hex);
+	if (!only_two_digit_prefix)
+		strbuf_addf(buf, "%s", hex+2);
+}
+
+char *get_remote_object_url(const char *url, const char *hex,
+			    int only_two_digit_prefix)
+{
+	struct strbuf buf = STRBUF_INIT;
+	append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
+	return strbuf_detach(&buf, NULL);
+}
+
+/* http_request() targets */
+#define HTTP_REQUEST_STRBUF	0
+#define HTTP_REQUEST_FILE	1
+
+static int http_request(const char *url, void *result, int target, int options)
+{
+	struct active_request_slot *slot;
+	struct slot_results results;
+	struct curl_slist *headers = NULL;
+	struct strbuf buf = STRBUF_INIT;
+	int ret;
+
+	slot = get_active_slot();
+	slot->results = &results;
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+
+	if (result == NULL) {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
+	} else {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
+
+		if (target == HTTP_REQUEST_FILE) {
+			long posn = ftell(result);
+			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+					 fwrite);
+			if (posn > 0) {
+				strbuf_addf(&buf, "Range: bytes=%ld-", posn);
+				headers = curl_slist_append(headers, buf.buf);
+				strbuf_reset(&buf);
+			}
+			slot->local = result;
+		} else
+			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+					 fwrite_buffer);
+	}
+
+	strbuf_addstr(&buf, "Pragma:");
+	if (options & HTTP_NO_CACHE)
+		strbuf_addstr(&buf, " no-cache");
+
+	headers = curl_slist_append(headers, buf.buf);
+
+	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
+
+	if (start_active_slot(slot)) {
+		run_active_slot(slot);
+		if (results.curl_result == CURLE_OK)
+			ret = HTTP_OK;
+		else if (missing_target(&results))
+			ret = HTTP_MISSING_TARGET;
+		else if (results.http_code == 401) {
+			if (user_name) {
+				ret = HTTP_NOAUTH;
+			} else {
+				/*
+				 * git_getpass is needed here because its very likely stdin/stdout are
+				 * pipes to our parent process.  So we instead need to use /dev/tty,
+				 * but that is non-portable.  Using git_getpass() can at least be stubbed
+				 * on other platforms with a different implementation if/when necessary.
+				 */
+				user_name = xstrdup(git_getpass("Username: "));
+				init_curl_http_auth(slot->curl);
+				ret = HTTP_REAUTH;
+			}
+		} else
+			ret = HTTP_ERROR;
+	} else {
+		error("Unable to start HTTP request for %s", url);
+		ret = HTTP_START_FAILED;
+	}
+
+	slot->local = NULL;
+	curl_slist_free_all(headers);
+	strbuf_release(&buf);
+
+	return ret;
+}
+
+int http_get_strbuf(const char *url, struct strbuf *result, int options)
+{
+	int http_ret = http_request(url, result, HTTP_REQUEST_STRBUF, options);
+	if (http_ret == HTTP_REAUTH) {
+		http_ret = http_request(url, result, HTTP_REQUEST_STRBUF, options);
+	}
+	return http_ret;
+}
+
+/*
+ * Downloads an url and stores the result in the given file.
+ *
+ * If a previous interrupted download is detected (i.e. a previous temporary
+ * file is still around) the download is resumed.
+ */
+static int http_get_file(const char *url, const char *filename, int options)
+{
+	int ret;
+	struct strbuf tmpfile = STRBUF_INIT;
+	FILE *result;
+
+	strbuf_addf(&tmpfile, "%s.temp", filename);
+	result = fopen(tmpfile.buf, "a");
+	if (! result) {
+		error("Unable to open local file %s", tmpfile.buf);
+		ret = HTTP_ERROR;
+		goto cleanup;
+	}
+
+	ret = http_request(url, result, HTTP_REQUEST_FILE, options);
+	fclose(result);
+
+	if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
+		ret = HTTP_ERROR;
+cleanup:
+	strbuf_release(&tmpfile);
+	return ret;
+}
+
+int http_error(const char *url, int ret)
+{
+	/* http_request has already handled HTTP_START_FAILED. */
+	if (ret != HTTP_START_FAILED)
+		error("%s while accessing %s\n", curl_errorstr, url);
+
+	return ret;
+}
+
+int http_fetch_ref(const char *base, struct ref *ref)
+{
+	char *url;
+	struct strbuf buffer = STRBUF_INIT;
+	int ret = -1;
+
+	url = quote_ref_url(base, ref->name);
+	if (http_get_strbuf(url, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
+		strbuf_rtrim(&buffer);
+		if (buffer.len == 40)
+			ret = get_sha1_hex(buffer.buf, ref->old_sha1);
+		else if (!prefixcmp(buffer.buf, "ref: ")) {
+			ref->symref = xstrdup(buffer.buf + 5);
+			ret = 0;
+		}
+	}
+
+	strbuf_release(&buffer);
+	free(url);
+	return ret;
+}
+
+/* Helpers for fetching packs */
+static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
+{
+	char *url, *tmp;
+	struct strbuf buf = STRBUF_INIT;
+
+	if (http_is_verbose)
+		fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
+	url = strbuf_detach(&buf, NULL);
+
+	strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
+	tmp = strbuf_detach(&buf, NULL);
+
+	if (http_get_file(url, tmp, 0) != HTTP_OK) {
+		error("Unable to get pack index %s\n", url);
+		free(tmp);
+		tmp = NULL;
+	}
+
+	free(url);
+	return tmp;
+}
+
+static int fetch_and_setup_pack_index(struct packed_git **packs_head,
+	unsigned char *sha1, const char *base_url)
+{
+	struct packed_git *new_pack;
+	char *tmp_idx = NULL;
+	int ret;
+
+	if (has_pack_index(sha1)) {
+		new_pack = parse_pack_index(sha1, NULL);
+		if (!new_pack)
+			return -1; /* parse_pack_index() already issued error message */
+		goto add_pack;
+	}
+
+	tmp_idx = fetch_pack_index(sha1, base_url);
+	if (!tmp_idx)
+		return -1;
+
+	new_pack = parse_pack_index(sha1, tmp_idx);
+	if (!new_pack) {
+		unlink(tmp_idx);
+		free(tmp_idx);
+
+		return -1; /* parse_pack_index() already issued error message */
+	}
+
+	ret = verify_pack_index(new_pack);
+	if (!ret) {
+		close_pack_index(new_pack);
+		ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
+	}
+	free(tmp_idx);
+	if (ret)
+		return -1;
+
+add_pack:
+	new_pack->next = *packs_head;
+	*packs_head = new_pack;
+	return 0;
+}
+
+int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
+{
+	int ret = 0, i = 0;
+	char *url, *data;
+	struct strbuf buf = STRBUF_INIT;
+	unsigned char sha1[20];
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addstr(&buf, "objects/info/packs");
+	url = strbuf_detach(&buf, NULL);
+
+	ret = http_get_strbuf(url, &buf, HTTP_NO_CACHE);
+	if (ret != HTTP_OK)
+		goto cleanup;
+
+	data = buf.buf;
+	while (i < buf.len) {
+		switch (data[i]) {
+		case 'P':
+			i++;
+			if (i + 52 <= buf.len &&
+			    !prefixcmp(data + i, " pack-") &&
+			    !prefixcmp(data + i + 46, ".pack\n")) {
+				get_sha1_hex(data + i + 6, sha1);
+				fetch_and_setup_pack_index(packs_head, sha1,
+						      base_url);
+				i += 51;
+				break;
+			}
+		default:
+			while (i < buf.len && data[i] != '\n')
+				i++;
+		}
+		i++;
+	}
+
+cleanup:
+	free(url);
+	return ret;
+}
+
+void release_http_pack_request(struct http_pack_request *preq)
+{
+	if (preq->packfile != NULL) {
+		fclose(preq->packfile);
+		preq->packfile = NULL;
+		preq->slot->local = NULL;
+	}
+	if (preq->range_header != NULL) {
+		curl_slist_free_all(preq->range_header);
+		preq->range_header = NULL;
+	}
+	preq->slot = NULL;
+	free(preq->url);
+}
+
+int finish_http_pack_request(struct http_pack_request *preq)
+{
+	struct packed_git **lst;
+	struct packed_git *p = preq->target;
+	char *tmp_idx;
+	struct child_process ip;
+	const char *ip_argv[8];
+
+	close_pack_index(p);
+
+	fclose(preq->packfile);
+	preq->packfile = NULL;
+	preq->slot->local = NULL;
+
+	lst = preq->lst;
+	while (*lst != p)
+		lst = &((*lst)->next);
+	*lst = (*lst)->next;
+
+	tmp_idx = xstrdup(preq->tmpfile);
+	strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
+	       ".idx.temp");
+
+	ip_argv[0] = "index-pack";
+	ip_argv[1] = "-o";
+	ip_argv[2] = tmp_idx;
+	ip_argv[3] = preq->tmpfile;
+	ip_argv[4] = NULL;
+
+	memset(&ip, 0, sizeof(ip));
+	ip.argv = ip_argv;
+	ip.git_cmd = 1;
+	ip.no_stdin = 1;
+	ip.no_stdout = 1;
+
+	if (run_command(&ip)) {
+		unlink(preq->tmpfile);
+		unlink(tmp_idx);
+		free(tmp_idx);
+		return -1;
+	}
+
+	unlink(sha1_pack_index_name(p->sha1));
+
+	if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
+	 || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
+		free(tmp_idx);
+		return -1;
+	}
+
+	install_packed_git(p);
+	free(tmp_idx);
+	return 0;
+}
+
+struct http_pack_request *new_http_pack_request(
+	struct packed_git *target, const char *base_url)
+{
+	long prev_posn = 0;
+	char range[RANGE_HEADER_SIZE];
+	struct strbuf buf = STRBUF_INIT;
+	struct http_pack_request *preq;
+
+	preq = xmalloc(sizeof(*preq));
+	preq->target = target;
+	preq->range_header = NULL;
+
+	end_url_with_slash(&buf, base_url);
+	strbuf_addf(&buf, "objects/pack/pack-%s.pack",
+		sha1_to_hex(target->sha1));
+	preq->url = strbuf_detach(&buf, NULL);
+
+	snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
+		sha1_pack_name(target->sha1));
+	preq->packfile = fopen(preq->tmpfile, "a");
+	if (!preq->packfile) {
+		error("Unable to open local file %s for pack",
+		      preq->tmpfile);
+		goto abort;
+	}
+
+	preq->slot = get_active_slot();
+	preq->slot->local = preq->packfile;
+	curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
+	curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+		no_pragma_header);
+
+	/*
+	 * If there is data present from a previous transfer attempt,
+	 * resume where it left off
+	 */
+	prev_posn = ftell(preq->packfile);
+	if (prev_posn>0) {
+		if (http_is_verbose)
+			fprintf(stderr,
+				"Resuming fetch of pack %s at byte %ld\n",
+				sha1_to_hex(target->sha1), prev_posn);
+		sprintf(range, "Range: bytes=%ld-", prev_posn);
+		preq->range_header = curl_slist_append(NULL, range);
+		curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+			preq->range_header);
+	}
+
+	return preq;
+
+abort:
+	free(preq->url);
+	free(preq);
+	return NULL;
+}
+
+/* Helpers for fetching objects (loose) */
+static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
+			       void *data)
+{
+	unsigned char expn[4096];
+	size_t size = eltsize * nmemb;
+	int posn = 0;
+	struct http_object_request *freq =
+		(struct http_object_request *)data;
+	do {
+		ssize_t retval = xwrite(freq->localfile,
+					(char *) ptr + posn, size - posn);
+		if (retval < 0)
+			return posn;
+		posn += retval;
+	} while (posn < size);
+
+	freq->stream.avail_in = size;
+	freq->stream.next_in = ptr;
+	do {
+		freq->stream.next_out = expn;
+		freq->stream.avail_out = sizeof(expn);
+		freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
+		git_SHA1_Update(&freq->c, expn,
+				sizeof(expn) - freq->stream.avail_out);
+	} while (freq->stream.avail_in && freq->zret == Z_OK);
+	data_received++;
+	return size;
+}
+
+struct http_object_request *new_http_object_request(const char *base_url,
+	unsigned char *sha1)
+{
+	char *hex = sha1_to_hex(sha1);
+	char *filename;
+	char prevfile[PATH_MAX];
+	int prevlocal;
+	unsigned char prev_buf[PREV_BUF_SIZE];
+	ssize_t prev_read = 0;
+	long prev_posn = 0;
+	char range[RANGE_HEADER_SIZE];
+	struct curl_slist *range_header = NULL;
+	struct http_object_request *freq;
+
+	freq = xmalloc(sizeof(*freq));
+	hashcpy(freq->sha1, sha1);
+	freq->localfile = -1;
+
+	filename = sha1_file_name(sha1);
+	snprintf(freq->tmpfile, sizeof(freq->tmpfile),
+		 "%s.temp", filename);
+
+	snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
+	unlink_or_warn(prevfile);
+	rename(freq->tmpfile, prevfile);
+	unlink_or_warn(freq->tmpfile);
+
+	if (freq->localfile != -1)
+		error("fd leakage in start: %d", freq->localfile);
+	freq->localfile = open(freq->tmpfile,
+			       O_WRONLY | O_CREAT | O_EXCL, 0666);
+	/*
+	 * This could have failed due to the "lazy directory creation";
+	 * try to mkdir the last path component.
+	 */
+	if (freq->localfile < 0 && errno == ENOENT) {
+		char *dir = strrchr(freq->tmpfile, '/');
+		if (dir) {
+			*dir = 0;
+			mkdir(freq->tmpfile, 0777);
+			*dir = '/';
+		}
+		freq->localfile = open(freq->tmpfile,
+				       O_WRONLY | O_CREAT | O_EXCL, 0666);
+	}
+
+	if (freq->localfile < 0) {
+		error("Couldn't create temporary file %s: %s",
+		      freq->tmpfile, strerror(errno));
+		goto abort;
+	}
+
+	memset(&freq->stream, 0, sizeof(freq->stream));
+
+	git_inflate_init(&freq->stream);
+
+	git_SHA1_Init(&freq->c);
+
+	freq->url = get_remote_object_url(base_url, hex, 0);
+
+	/*
+	 * If a previous temp file is present, process what was already
+	 * fetched.
+	 */
+	prevlocal = open(prevfile, O_RDONLY);
+	if (prevlocal != -1) {
+		do {
+			prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
+			if (prev_read>0) {
+				if (fwrite_sha1_file(prev_buf,
+						     1,
+						     prev_read,
+						     freq) == prev_read) {
+					prev_posn += prev_read;
+				} else {
+					prev_read = -1;
+				}
+			}
+		} while (prev_read > 0);
+		close(prevlocal);
+	}
+	unlink_or_warn(prevfile);
+
+	/*
+	 * Reset inflate/SHA1 if there was an error reading the previous temp
+	 * file; also rewind to the beginning of the local file.
+	 */
+	if (prev_read == -1) {
+		memset(&freq->stream, 0, sizeof(freq->stream));
+		git_inflate_init(&freq->stream);
+		git_SHA1_Init(&freq->c);
+		if (prev_posn>0) {
+			prev_posn = 0;
+			lseek(freq->localfile, 0, SEEK_SET);
+			if (ftruncate(freq->localfile, 0) < 0) {
+				error("Couldn't truncate temporary file %s: %s",
+					  freq->tmpfile, strerror(errno));
+				goto abort;
+			}
+		}
+	}
+
+	freq->slot = get_active_slot();
+
+	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
+	curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
+
+	/*
+	 * If we have successfully processed data from a previous fetch
+	 * attempt, only fetch the data we don't already have.
+	 */
+	if (prev_posn>0) {
+		if (http_is_verbose)
+			fprintf(stderr,
+				"Resuming fetch of object %s at byte %ld\n",
+				hex, prev_posn);
+		sprintf(range, "Range: bytes=%ld-", prev_posn);
+		range_header = curl_slist_append(range_header, range);
+		curl_easy_setopt(freq->slot->curl,
+				 CURLOPT_HTTPHEADER, range_header);
+	}
+
+	return freq;
+
+abort:
+	free(filename);
+	free(freq->url);
+	free(freq);
+	return NULL;
+}
+
+void process_http_object_request(struct http_object_request *freq)
+{
+	if (freq->slot == NULL)
+		return;
+	freq->curl_result = freq->slot->curl_result;
+	freq->http_code = freq->slot->http_code;
+	freq->slot = NULL;
+}
+
+int finish_http_object_request(struct http_object_request *freq)
+{
+	struct stat st;
+
+	close(freq->localfile);
+	freq->localfile = -1;
+
+	process_http_object_request(freq);
+
+	if (freq->http_code == 416) {
+		warning("requested range invalid; we may already have all the data.");
+	} else if (freq->curl_result != CURLE_OK) {
+		if (stat(freq->tmpfile, &st) == 0)
+			if (st.st_size == 0)
+				unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+
+	git_inflate_end(&freq->stream);
+	git_SHA1_Final(freq->real_sha1, &freq->c);
+	if (freq->zret != Z_STREAM_END) {
+		unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+	if (hashcmp(freq->sha1, freq->real_sha1)) {
+		unlink_or_warn(freq->tmpfile);
+		return -1;
+	}
+	freq->rename =
+		move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
+
+	return freq->rename;
+}
+
+void abort_http_object_request(struct http_object_request *freq)
+{
+	unlink_or_warn(freq->tmpfile);
+
+	release_http_object_request(freq);
+}
+
+void release_http_object_request(struct http_object_request *freq)
+{
+	if (freq->localfile != -1) {
+		close(freq->localfile);
+		freq->localfile = -1;
+	}
+	if (freq->url != NULL) {
+		free(freq->url);
+		freq->url = NULL;
+	}
+	if (freq->slot != NULL) {
+		freq->slot->callback_func = NULL;
+		freq->slot->callback_data = NULL;
+		release_active_slot(freq->slot);
+		freq->slot = NULL;
+	}
+}