Merge branch 'ew/http-do-not-forget-to-call-curl-multi-remove-handle'
[git/git.git] / http.c
diff --git a/http.c b/http.c
index 6a97783..82ed542 100644 (file)
--- a/http.c
+++ b/http.c
 #include "gettext.h"
 #include "transport.h"
 
+static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
+#if LIBCURL_VERSION_NUM >= 0x070a08
+long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
+#else
+long int git_curl_ipresolve;
+#endif
 int active_requests;
 int http_is_verbose;
 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
@@ -30,7 +36,6 @@ static CURL *curl_default;
 #endif
 
 #define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
 
 char curl_errorstr[CURL_ERROR_SIZE];
 
@@ -58,16 +63,41 @@ static const char *ssl_key;
 #if LIBCURL_VERSION_NUM >= 0x070908
 static const char *ssl_capath;
 #endif
+#if LIBCURL_VERSION_NUM >= 0x072c00
+static const char *ssl_pinnedkey;
+#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 const char *curl_no_proxy;
+static const char *http_proxy_authmethod;
+static struct {
+       const char *name;
+       long curlauth_param;
+} proxy_authmethods[] = {
+       { "basic", CURLAUTH_BASIC },
+       { "digest", CURLAUTH_DIGEST },
+       { "negotiate", CURLAUTH_GSSNEGOTIATE },
+       { "ntlm", CURLAUTH_NTLM },
+#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
+       { "anyauth", CURLAUTH_ANY },
+#endif
+       /*
+        * CURLAUTH_DIGEST_IE has no corresponding command-line option in
+        * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
+        * here, too
+        */
+};
+static struct credential proxy_auth = CREDENTIAL_INIT;
+static const char *curl_proxyuserpwd;
 static const char *curl_cookie_file;
 static int curl_save_cookies;
 struct credential http_auth = CREDENTIAL_INIT;
 static int http_proactive_auth;
 static const char *user_agent;
+static int curl_empty_auth;
 
 #if LIBCURL_VERSION_NUM >= 0x071700
 /* Use CURLOPT_KEYPASSWD as is */
@@ -85,6 +115,7 @@ static unsigned long http_auth_methods = CURLAUTH_ANY;
 
 static struct curl_slist *pragma_header;
 static struct curl_slist *no_pragma_header;
+static struct curl_slist *extra_http_headers;
 
 static struct active_request_slot *active_queue_head;
 
@@ -160,6 +191,9 @@ static void finish_active_slot(struct active_request_slot *slot)
 #else
                slot->results->auth_avail = 0;
 #endif
+
+               curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
+                       &slot->results->http_connectcode);
        }
 
        /* Run callback if appropriate */
@@ -264,8 +298,11 @@ static int http_options(const char *var, const char *value, void *cb)
        if (!strcmp("http.proxy", var))
                return git_config_string(&curl_http_proxy, var, value);
 
+       if (!strcmp("http.proxyauthmethod", var))
+               return git_config_string(&http_proxy_authmethod, var, value);
+
        if (!strcmp("http.cookiefile", var))
-               return git_config_string(&curl_cookie_file, var, value);
+               return git_config_pathname(&curl_cookie_file, var, value);
        if (!strcmp("http.savecookies", var)) {
                curl_save_cookies = git_config_bool(var, value);
                return 0;
@@ -281,14 +318,44 @@ static int http_options(const char *var, const char *value, void *cb)
        if (!strcmp("http.useragent", var))
                return git_config_string(&user_agent, var, value);
 
+       if (!strcmp("http.emptyauth", var)) {
+               curl_empty_auth = git_config_bool(var, value);
+               return 0;
+       }
+
+       if (!strcmp("http.pinnedpubkey", var)) {
+#if LIBCURL_VERSION_NUM >= 0x072c00
+               return git_config_pathname(&ssl_pinnedkey, var, value);
+#else
+               warning(_("Public key pinning not supported with cURL < 7.44.0"));
+               return 0;
+#endif
+       }
+
+       if (!strcmp("http.extraheader", var)) {
+               if (!value) {
+                       return config_error_nonbool(var);
+               } else if (!*value) {
+                       curl_slist_free_all(extra_http_headers);
+                       extra_http_headers = NULL;
+               } else {
+                       extra_http_headers =
+                               curl_slist_append(extra_http_headers, value);
+               }
+               return 0;
+       }
+
        /* Fall back on the default ones */
        return git_default_config(var, value, cb);
 }
 
 static void init_curl_http_auth(CURL *result)
 {
-       if (!http_auth.username)
+       if (!http_auth.username) {
+               if (curl_empty_auth)
+                       curl_easy_setopt(result, CURLOPT_USERPWD, ":");
                return;
+       }
 
        credential_fill(&http_auth);
 
@@ -312,6 +379,64 @@ static void init_curl_http_auth(CURL *result)
 #endif
 }
 
+/* *var must be free-able */
+static void var_override(const char **var, char *value)
+{
+       if (value) {
+               free((void *)*var);
+               *var = xstrdup(value);
+       }
+}
+
+static void set_proxyauth_name_password(CURL *result)
+{
+#if LIBCURL_VERSION_NUM >= 0x071301
+               curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
+                       proxy_auth.username);
+               curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
+                       proxy_auth.password);
+#else
+               struct strbuf s = STRBUF_INIT;
+
+               strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
+               strbuf_addch(&s, ':');
+               strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
+               curl_proxyuserpwd = strbuf_detach(&s, NULL);
+               curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
+#endif
+}
+
+static void init_curl_proxy_auth(CURL *result)
+{
+       if (proxy_auth.username) {
+               if (!proxy_auth.password)
+                       credential_fill(&proxy_auth);
+               set_proxyauth_name_password(result);
+       }
+
+       var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
+
+#if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
+       if (http_proxy_authmethod) {
+               int i;
+               for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
+                       if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
+                               curl_easy_setopt(result, CURLOPT_PROXYAUTH,
+                                               proxy_authmethods[i].curlauth_param);
+                               break;
+                       }
+               }
+               if (i == ARRAY_SIZE(proxy_authmethods)) {
+                       warning("unsupported proxy authentication method %s: using anyauth",
+                                       http_proxy_authmethod);
+                       curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
+               }
+       }
+       else
+               curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
+#endif
+}
+
 static int has_cert_password(void)
 {
        if (ssl_cert == NULL || ssl_cert_password_required != 1)
@@ -343,8 +468,7 @@ static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 
        rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
        if (rc < 0)
-               warning("unable to set SO_KEEPALIVE on socket %s",
-                       strerror(errno));
+               warning_errno("unable to set SO_KEEPALIVE on socket");
 
        return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 }
@@ -361,6 +485,125 @@ static void set_curl_keepalive(CURL *c)
 }
 #endif
 
+static void redact_sensitive_header(struct strbuf *header)
+{
+       const char *sensitive_header;
+
+       if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
+           skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
+               /* The first token is the type, which is OK to log */
+               while (isspace(*sensitive_header))
+                       sensitive_header++;
+               while (*sensitive_header && !isspace(*sensitive_header))
+                       sensitive_header++;
+               /* Everything else is opaque and possibly sensitive */
+               strbuf_setlen(header,  sensitive_header - header->buf);
+               strbuf_addstr(header, " <redacted>");
+       }
+}
+
+static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
+{
+       struct strbuf out = STRBUF_INIT;
+       struct strbuf **headers, **header;
+
+       strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
+               text, (long)size, (long)size);
+       trace_strbuf(&trace_curl, &out);
+       strbuf_reset(&out);
+       strbuf_add(&out, ptr, size);
+       headers = strbuf_split_max(&out, '\n', 0);
+
+       for (header = headers; *header; header++) {
+               if (hide_sensitive_header)
+                       redact_sensitive_header(*header);
+               strbuf_insert((*header), 0, text, strlen(text));
+               strbuf_insert((*header), strlen(text), ": ", 2);
+               strbuf_rtrim((*header));
+               strbuf_addch((*header), '\n');
+               trace_strbuf(&trace_curl, (*header));
+       }
+       strbuf_list_free(headers);
+       strbuf_release(&out);
+}
+
+static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
+{
+       size_t i;
+       struct strbuf out = STRBUF_INIT;
+       unsigned int width = 60;
+
+       strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
+               text, (long)size, (long)size);
+       trace_strbuf(&trace_curl, &out);
+
+       for (i = 0; i < size; i += width) {
+               size_t w;
+
+               strbuf_reset(&out);
+               strbuf_addf(&out, "%s: ", text);
+               for (w = 0; (w < width) && (i + w < size); w++) {
+                       unsigned char ch = ptr[i + w];
+
+                       strbuf_addch(&out,
+                                      (ch >= 0x20) && (ch < 0x80)
+                                      ? ch : '.');
+               }
+               strbuf_addch(&out, '\n');
+               trace_strbuf(&trace_curl, &out);
+       }
+       strbuf_release(&out);
+}
+
+static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
+{
+       const char *text;
+       enum { NO_FILTER = 0, DO_FILTER = 1 };
+
+       switch (type) {
+       case CURLINFO_TEXT:
+               trace_printf_key(&trace_curl, "== Info: %s", data);
+       default:                /* we ignore unknown types by default */
+               return 0;
+
+       case CURLINFO_HEADER_OUT:
+               text = "=> Send header";
+               curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
+               break;
+       case CURLINFO_DATA_OUT:
+               text = "=> Send data";
+               curl_dump_data(text, (unsigned char *)data, size);
+               break;
+       case CURLINFO_SSL_DATA_OUT:
+               text = "=> Send SSL data";
+               curl_dump_data(text, (unsigned char *)data, size);
+               break;
+       case CURLINFO_HEADER_IN:
+               text = "<= Recv header";
+               curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
+               break;
+       case CURLINFO_DATA_IN:
+               text = "<= Recv data";
+               curl_dump_data(text, (unsigned char *)data, size);
+               break;
+       case CURLINFO_SSL_DATA_IN:
+               text = "<= Recv SSL data";
+               curl_dump_data(text, (unsigned char *)data, size);
+               break;
+       }
+       return 0;
+}
+
+void setup_curl_trace(CURL *handle)
+{
+       if (!trace_want(&trace_curl))
+               return;
+       curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
+       curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
+       curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
+}
+
+
 static CURL *get_curl_handle(void)
 {
        CURL *result = curl_easy_init();
@@ -422,6 +665,10 @@ static CURL *get_curl_handle(void)
 #if LIBCURL_VERSION_NUM >= 0x070908
        if (ssl_capath != NULL)
                curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
+#endif
+#if LIBCURL_VERSION_NUM >= 0x072c00
+       if (ssl_pinnedkey != NULL)
+               curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 #endif
        if (ssl_cainfo != NULL)
                curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
@@ -455,9 +702,9 @@ static CURL *get_curl_handle(void)
                warning("protocol restrictions not applied to curl redirects because\n"
                        "your curl version is too old (>= 7.19.4)");
 #endif
-
        if (getenv("GIT_CURL_VERBOSE"))
-               curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
+               curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
+       setup_curl_trace(result);
 
        curl_easy_setopt(result, CURLOPT_USERAGENT,
                user_agent ? user_agent : git_user_agent());
@@ -470,10 +717,38 @@ static CURL *get_curl_handle(void)
                curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 #endif
 
+       /*
+        * CURL also examines these variables as a fallback; but we need to query
+        * them here in order to decide whether to prompt for missing password (cf.
+        * init_curl_proxy_auth()).
+        *
+        * Unlike many other common environment variables, these are historically
+        * lowercase only. It appears that CURL did not know this and implemented
+        * only uppercase variants, which was later corrected to take both - with
+        * the exception of http_proxy, which is lowercase only also in CURL. As
+        * the lowercase versions are the historical quasi-standard, they take
+        * precedence here, as in CURL.
+        */
+       if (!curl_http_proxy) {
+               if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
+                       var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
+                       var_override(&curl_http_proxy, getenv("https_proxy"));
+               } else {
+                       var_override(&curl_http_proxy, getenv("http_proxy"));
+               }
+               if (!curl_http_proxy) {
+                       var_override(&curl_http_proxy, getenv("ALL_PROXY"));
+                       var_override(&curl_http_proxy, getenv("all_proxy"));
+               }
+       }
+
        if (curl_http_proxy) {
                curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 #if LIBCURL_VERSION_NUM >= 0x071800
-               if (starts_with(curl_http_proxy, "socks5"))
+               if (starts_with(curl_http_proxy, "socks5h"))
+                       curl_easy_setopt(result,
+                               CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
+               else if (starts_with(curl_http_proxy, "socks5"))
                        curl_easy_setopt(result,
                                CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
                else if (starts_with(curl_http_proxy, "socks4a"))
@@ -483,10 +758,23 @@ static CURL *get_curl_handle(void)
                        curl_easy_setopt(result,
                                CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 #endif
-       }
-#if LIBCURL_VERSION_NUM >= 0x070a07
-       curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
+               if (strstr(curl_http_proxy, "://"))
+                       credential_from_url(&proxy_auth, curl_http_proxy);
+               else {
+                       struct strbuf url = STRBUF_INIT;
+                       strbuf_addf(&url, "http://%s", curl_http_proxy);
+                       credential_from_url(&proxy_auth, url.buf);
+                       strbuf_release(&url);
+               }
+
+               curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
+#if LIBCURL_VERSION_NUM >= 0x071304
+               var_override(&curl_no_proxy, getenv("NO_PROXY"));
+               var_override(&curl_no_proxy, getenv("no_proxy"));
+               curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
 #endif
+       }
+       init_curl_proxy_auth(result);
 
        set_curl_keepalive(result);
 
@@ -527,8 +815,13 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
        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:");
+       if (remote)
+               var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
+
+       pragma_header = curl_slist_append(http_copy_default_headers(),
+               "Pragma: no-cache");
+       no_pragma_header = curl_slist_append(http_copy_default_headers(),
+               "Pragma:");
 
 #ifdef USE_CURL_MULTI
        {
@@ -612,6 +905,9 @@ void http_cleanup(void)
 #endif
        curl_global_cleanup();
 
+       curl_slist_free_all(extra_http_headers);
+       extra_http_headers = NULL;
+
        curl_slist_free_all(pragma_header);
        pragma_header = NULL;
 
@@ -623,6 +919,18 @@ void http_cleanup(void)
                curl_http_proxy = NULL;
        }
 
+       if (proxy_auth.password) {
+               memset(proxy_auth.password, 0, strlen(proxy_auth.password));
+               free(proxy_auth.password);
+               proxy_auth.password = NULL;
+       }
+
+       free((void *)curl_proxyuserpwd);
+       curl_proxyuserpwd = NULL;
+
+       free((void *)http_proxy_authmethod);
+       http_proxy_authmethod = NULL;
+
        if (cert_auth.password != NULL) {
                memset(cert_auth.password, 0, strlen(cert_auth.password));
                free(cert_auth.password);
@@ -697,10 +1005,15 @@ struct active_request_slot *get_active_slot(void)
        curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
        curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
        curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
+       curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
+
+#if LIBCURL_VERSION_NUM >= 0x070a08
+       curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
+#endif
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
        curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 #endif
-       if (http_auth.password)
+       if (http_auth.password || curl_empty_auth)
                init_curl_http_auth(slot->curl);
 
        return slot;
@@ -919,7 +1232,7 @@ void append_remote_object_url(struct strbuf *buf, const char *url,
 
        strbuf_addf(buf, "objects/%.*s/", 2, hex);
        if (!only_two_digit_prefix)
-               strbuf_addf(buf, "%s", hex+2);
+               strbuf_addstr(buf, hex + 2);
 }
 
 char *get_remote_object_url(const char *url, const char *hex,
@@ -953,6 +1266,8 @@ static int handle_curl_result(struct slot_results *results)
 
        if (results->curl_result == CURLE_OK) {
                credential_approve(&http_auth);
+               if (proxy_auth.password)
+                       credential_approve(&proxy_auth);
                return HTTP_OK;
        } else if (missing_target(results))
                return HTTP_MISSING_TARGET;
@@ -967,6 +1282,8 @@ static int handle_curl_result(struct slot_results *results)
                        return HTTP_REAUTH;
                }
        } else {
+               if (results->http_connectcode == 407)
+                       credential_reject(&proxy_auth);
 #if LIBCURL_VERSION_NUM >= 0x070c00
                if (!curl_errorstr[0])
                        strlcpy(curl_errorstr,
@@ -991,6 +1308,16 @@ int run_one_slot(struct active_request_slot *slot,
        return handle_curl_result(results);
 }
 
+struct curl_slist *http_copy_default_headers(void)
+{
+       struct curl_slist *headers = NULL, *h;
+
+       for (h = extra_http_headers; h; h = h->next)
+               headers = curl_slist_append(headers, h->data);
+
+       return headers;
+}
+
 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 {
        char *ptr;
@@ -1140,7 +1467,7 @@ static void write_accept_language(struct strbuf *buf)
                     decimal_places++, max_q *= 10)
                        ;
 
-               sprintf(q_format, ";q=0.%%0%dd", decimal_places);
+               xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
 
                strbuf_addstr(buf, "Accept-Language: ");
 
@@ -1191,6 +1518,13 @@ static const char *get_accept_language(void)
        return cached_accept_language;
 }
 
+static void http_opt_request_remainder(CURL *curl, off_t pos)
+{
+       char buf[128];
+       xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
+       curl_easy_setopt(curl, CURLOPT_RANGE, buf);
+}
+
 /* http_request() targets */
 #define HTTP_REQUEST_STRBUF    0
 #define HTTP_REQUEST_FILE      1
@@ -1201,7 +1535,7 @@ static int http_request(const char *url,
 {
        struct active_request_slot *slot;
        struct slot_results results;
-       struct curl_slist *headers = NULL;
+       struct curl_slist *headers = http_copy_default_headers();
        struct strbuf buf = STRBUF_INIT;
        const char *accept_language;
        int ret;
@@ -1216,14 +1550,11 @@ static int http_request(const char *url,
                curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
 
                if (target == HTTP_REQUEST_FILE) {
-                       long posn = ftell(result);
+                       off_t posn = ftello(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);
-                       }
+                       if (posn > 0)
+                               http_opt_request_remainder(slot->curl, posn);
                } else
                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
                                         fwrite_buffer);
@@ -1405,7 +1736,7 @@ int http_fetch_ref(const char *base, struct ref *ref)
        if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
                strbuf_rtrim(&buffer);
                if (buffer.len == 40)
-                       ret = get_sha1_hex(buffer.buf, ref->old_sha1);
+                       ret = get_oid_hex(buffer.buf, &ref->old_oid);
                else if (starts_with(buffer.buf, "ref: ")) {
                        ref->symref = xstrdup(buffer.buf + 5);
                        ret = 0;
@@ -1533,10 +1864,6 @@ void release_http_pack_request(struct http_pack_request *preq)
                fclose(preq->packfile);
                preq->packfile = NULL;
        }
-       if (preq->range_header != NULL) {
-               curl_slist_free_all(preq->range_header);
-               preq->range_header = NULL;
-       }
        preq->slot = NULL;
        free(preq->url);
        free(preq);
@@ -1547,6 +1874,7 @@ int finish_http_pack_request(struct http_pack_request *preq)
        struct packed_git **lst;
        struct packed_git *p = preq->target;
        char *tmp_idx;
+       size_t len;
        struct child_process ip = CHILD_PROCESS_INIT;
        const char *ip_argv[8];
 
@@ -1560,9 +1888,9 @@ int finish_http_pack_request(struct http_pack_request *preq)
                lst = &((*lst)->next);
        *lst = (*lst)->next;
 
-       tmp_idx = xstrdup(preq->tmpfile);
-       strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
-              ".idx.temp");
+       if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
+               die("BUG: pack tmpfile does not end in .pack.temp?");
+       tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
 
        ip_argv[0] = "index-pack";
        ip_argv[1] = "-o";
@@ -1598,8 +1926,7 @@ int finish_http_pack_request(struct http_pack_request *preq)
 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];
+       off_t prev_posn = 0;
        struct strbuf buf = STRBUF_INIT;
        struct http_pack_request *preq;
 
@@ -1631,16 +1958,13 @@ struct http_pack_request *new_http_pack_request(
         * If there is data present from a previous transfer attempt,
         * resume where it left off
         */
-       prev_posn = ftell(preq->packfile);
+       prev_posn = ftello(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);
+                               "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
+                               sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
+               http_opt_request_remainder(preq->slot->curl, prev_posn);
        }
 
        return preq;
@@ -1658,8 +1982,19 @@ static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
        unsigned char expn[4096];
        size_t size = eltsize * nmemb;
        int posn = 0;
-       struct http_object_request *freq =
-               (struct http_object_request *)data;
+       struct http_object_request *freq = data;
+       struct active_request_slot *slot = freq->slot;
+
+       if (slot) {
+               CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
+                                               &slot->http_code);
+               if (c != CURLE_OK)
+                       die("BUG: curl_easy_getinfo for HTTP code failed: %s",
+                               curl_easy_strerror(c));
+               if (slot->http_code >= 400)
+                       return size;
+       }
+
        do {
                ssize_t retval = xwrite(freq->localfile,
                                        (char *) ptr + posn, size - posn);
@@ -1689,9 +2024,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        int prevlocal;
        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;
+       off_t prev_posn = 0;
        struct http_object_request *freq;
 
        freq = xcalloc(1, sizeof(*freq));
@@ -1727,8 +2060,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        }
 
        if (freq->localfile < 0) {
-               error("Couldn't create temporary file %s: %s",
-                     freq->tmpfile, strerror(errno));
+               error_errno("Couldn't create temporary file %s", freq->tmpfile);
                goto abort;
        }
 
@@ -1773,8 +2105,8 @@ struct http_object_request *new_http_object_request(const char *base_url,
                        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));
+                               error_errno("Couldn't truncate temporary file %s",
+                                           freq->tmpfile);
                                goto abort;
                        }
                }
@@ -1783,6 +2115,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        freq->slot = get_active_slot();
 
        curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
        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);
@@ -1795,12 +2128,9 @@ struct http_object_request *new_http_object_request(const char *base_url,
        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);
+                               "Resuming fetch of object %s at byte %"PRIuMAX"\n",
+                               hex, (uintmax_t)prev_posn);
+               http_opt_request_remainder(freq->slot->curl, prev_posn);
        }
 
        return freq;