Split the tracker code into a generic part and a http specific part. This

allows me to add code for other types of trackers.

Remove the curl interface glue, since I use my own http client now. The curl
code was my main reason for using threads, so I'm a large step closer to make
btpd unthreaded again.

5 files changed, 284 insertions, 433 deletions

diff --git a/btpd/http.c b/btpd/http.c
deleted file mode 100644
index f1e6b7e..0000000
--- a/btpd/http.c
+++ /dev/null
@@ -1,251 +0,0 @@
-#include <pthread.h>
-#include <stdarg.h>
-#include <string.h>
-#include <unistd.h>
-#include <curl/curl.h>
-
-#include "btpd.h"
-#include "http.h"
-
-#define MAX_DOWNLOAD (1 << 18)  // 256kB
-#define CURL_SELECT_TIME (& (struct timeval) { 1, 0 })
-
-enum http_state {
-    HS_ADD,
-    HS_ACTIVE,
-    HS_DONE,
-    HS_NOADD,
-    HS_CANCEL
-};
-
-struct http {
-    long t_created;
-    enum http_state state;
-    char *url;
-    CURL *curlh;
-    struct http_res res;
-    BTPDQ_ENTRY(http) entry;
-    void (*cb)(struct http *, struct http_res *, void *);
-    void *cb_arg;
-};
-
-BTPDQ_HEAD(http_tq, http);
-
-static struct http_tq m_httpq = BTPDQ_HEAD_INITIALIZER(m_httpq);
-static pthread_mutex_t m_httpq_lock;
-static pthread_cond_t m_httpq_cond;
-static CURLM *m_curlh;
-
-static size_t
-http_write_cb(void *ptr, size_t size, size_t nmemb, void *arg)
-{
-    char *mem;
-    struct http_res *res = arg;
-    size_t nbytes = size * nmemb;
-    size_t nlength = res->length + nbytes;
-    if (nlength > MAX_DOWNLOAD)
-        return 0;
-    if ((mem = realloc(res->content, nlength)) == NULL)
-        return 0;
-    res->content = mem;
-    bcopy(ptr, res->content + res->length, nbytes);
-    res->length = nlength;
-    return nbytes;
-}
-
-int
-http_get(struct http **ret,
-    void (*cb)(struct http *, struct http_res *, void *), void *arg,
-    const char *fmt, ...)
-{
-    struct http *h = btpd_calloc(1, sizeof(*h));
-
-    h->state = HS_ADD;
-    h->cb = cb;
-    h->cb_arg = arg;
-    h->t_created = btpd_seconds;
-    if ((h->curlh = curl_easy_init()) == NULL)
-        btpd_err("Fatal error in curl.\n");
-
-    va_list ap;
-    va_start(ap, fmt);
-    if (vasprintf(&h->url, fmt, ap) == -1)
-        btpd_err("Out of memory.\n");
-    va_end(ap);
-
-    curl_easy_setopt(h->curlh, CURLOPT_URL, h->url);
-    curl_easy_setopt(h->curlh, CURLOPT_USERAGENT, BTPD_VERSION);
-    curl_easy_setopt(h->curlh, CURLOPT_WRITEFUNCTION, http_write_cb);
-    curl_easy_setopt(h->curlh, CURLOPT_WRITEDATA, &h->res);
-    curl_easy_setopt(h->curlh, CURLOPT_FOLLOWLOCATION, 1);
-
-    pthread_mutex_lock(&m_httpq_lock);
-    BTPDQ_INSERT_TAIL(&m_httpq, h, entry);
-    pthread_mutex_unlock(&m_httpq_lock);
-    pthread_cond_signal(&m_httpq_cond);
-
-    if (ret != NULL)
-        *ret = h;
-
-    return 0;
-}
-
-long
-http_server_busy_time(const char *url, long s)
-{
-    struct http *h;
-    size_t len = strlen(url);
-
-    pthread_mutex_lock(&m_httpq_lock);
-    h = BTPDQ_LAST(&m_httpq, http_tq);
-    while (h != NULL &&
-            !((h->state == HS_ACTIVE || h->state == HS_ADD) &&
-                strncmp(url, h->url, len) == 0))
-        h = BTPDQ_PREV(h, http_tq, entry);
-    pthread_mutex_unlock(&m_httpq_lock);
-
-    if (h == NULL || btpd_seconds - h->t_created >= s)
-        return 0;
-    else
-        return s - (btpd_seconds - h->t_created);
-}
-
-void
-http_cancel(struct http *http)
-{
-    pthread_mutex_lock(&m_httpq_lock);
-    if (http->state == HS_ADD)
-        http->state = HS_NOADD;
-    else
-        http->state = HS_CANCEL;
-    pthread_mutex_unlock(&m_httpq_lock);
-}
-
-int
-http_succeeded(struct http_res *res)
-{
-    return res->res == HRES_OK && res->code >= 200 && res->code < 300;
-}
-
-static void
-http_td_cb(void *arg)
-{
-    struct http *h = arg;
-    if (h->res.res == HRES_OK)
-        curl_easy_getinfo(h->curlh, CURLINFO_RESPONSE_CODE, &h->res.code);
-    if (h->res.res == HRES_FAIL)
-        h->res.errmsg = curl_easy_strerror(h->res.code);
-    if (h->state != HS_CANCEL)
-        h->cb(h, &h->res, h->cb_arg);
-    curl_easy_cleanup(h->curlh);
-    if (h->res.content != NULL)
-        free(h->res.content);
-    free(h->url);
-    free(h);
-}
-
-static void
-http_td_actions(void)
-{
-    int nmsgs;
-    struct http *http, *next;
-    struct http_tq postq;
-    CURLMsg *cmsg;
-
-    pthread_mutex_lock(&m_httpq_lock);
-    do {
-        while (BTPDQ_EMPTY(&m_httpq))
-            pthread_cond_wait(&m_httpq_cond, &m_httpq_lock);
-
-        BTPDQ_INIT(&postq);
-
-        BTPDQ_FOREACH_MUTABLE(http, &m_httpq, entry, next) {
-            switch (http->state) {
-            case HS_ADD:
-                curl_multi_add_handle(m_curlh, http->curlh);
-                http->state = HS_ACTIVE;
-                break;
-            case HS_CANCEL:
-                curl_multi_remove_handle(m_curlh, http->curlh);
-            case HS_NOADD:
-                BTPDQ_REMOVE(&m_httpq, http, entry);
-                BTPDQ_INSERT_TAIL(&postq, http, entry);
-                http->state = HS_CANCEL;
-                http->res.res = HRES_CANCEL;
-                break;
-            case HS_DONE:
-                abort();
-            default:
-                break;
-            }
-        }
-
-        while ((cmsg = curl_multi_info_read(m_curlh, &nmsgs)) != NULL) {
-            BTPDQ_FOREACH(http, &m_httpq, entry) {
-                if (http->curlh == cmsg->easy_handle)
-                    break;
-            }
-            assert(http != NULL);
-            BTPDQ_REMOVE(&m_httpq, http, entry);
-            BTPDQ_INSERT_TAIL(&postq, http, entry);
-            http->state = HS_DONE;
-            if (cmsg->data.result == 0)
-                http->res.res = HRES_OK;
-            else {
-                http->res.res = HRES_FAIL;
-                http->res.code = cmsg->data.result;
-            }
-            curl_multi_remove_handle(m_curlh, http->curlh);
-        }
-
-        if (!BTPDQ_EMPTY(&postq)) {
-            pthread_mutex_unlock(&m_httpq_lock);
-            td_post_begin();
-            BTPDQ_FOREACH(http, &postq, entry)
-                td_post(http_td_cb, http);
-            td_post_end();
-            pthread_mutex_lock(&m_httpq_lock);
-        }
-    } while (BTPDQ_EMPTY(&m_httpq));
-    pthread_mutex_unlock(&m_httpq_lock);
-}
-
-static void
-http_td(void *arg)
-{
-    fd_set rset, wset, eset;
-    int maxfd, nbusy;
-
-    for (;;) {
-        http_td_actions();
-
-        while (CURLM_CALL_MULTI_PERFORM == curl_multi_perform(m_curlh, &nbusy))
-            ;
-
-        if (nbusy > 0) {
-            FD_ZERO(&rset);
-            FD_ZERO(&wset);
-            FD_ZERO(&eset);
-            curl_multi_fdset(m_curlh, &rset, &wset, &eset, &maxfd);
-            select(maxfd + 1, &rset, &wset, &eset, CURL_SELECT_TIME);
-        }
-    }
-}
-
-static void
-errdie(int err)
-{
-    if (err != 0)
-        btpd_err("Fatal error in http_init.\n");
-}
-
-void
-http_init(void)
-{
-    pthread_t ret;
-    errdie(curl_global_init(0));
-    errdie((m_curlh = curl_multi_init()) == NULL);
-    errdie(pthread_mutex_init(&m_httpq_lock, NULL));
-    errdie(pthread_cond_init(&m_httpq_cond, NULL));
-    errdie(pthread_create(&ret, NULL, (void *(*)(void *))http_td, NULL));
-}
diff --git a/btpd/http.h b/btpd/http.h
deleted file mode 100644
index 9f03614..0000000
--- a/btpd/http.h
+++ /dev/null
@@ -1,32 +0,0 @@
-#ifndef BTPD_HTTP_H
-#define BTPD_HTTP_H
-
-struct http;
-
-enum http_status {
-    HRES_OK,
-    HRES_FAIL,
-    HRES_CANCEL
-};
-
-struct http_res {
-    enum http_status res;
-    long code;
-    const char *errmsg;
-    char *content;
-    size_t length;
-};
-
-__attribute__((format (printf, 4, 5)))
-int http_get(struct http **ret,
-    void (*cb)(struct http *, struct http_res *, void *),
-    void *arg,
-    const char *fmt, ...);
-void http_cancel(struct http *http);
-int http_succeeded(struct http_res *res);
-
-long http_server_busy_time(const char *url, long s);
-
-void http_init(void);
-
-#endif
diff --git a/btpd/http_tr_if.c b/btpd/http_tr_if.c
new file mode 100644
index 0000000..568b93c
--- /dev/null
+++ b/btpd/http_tr_if.c
@@ -0,0 +1,174 @@
+#include <string.h>
+
+#include "btpd.h"
+#include "tracker_req.h"
+#include "http_client.h"
+
+#define MAX_DOWNLOAD (1 << 18)  // 256kB
+
+static const char *m_tr_events[] = { "started", "stopped", "completed", "" };
+
+struct http_tr_req {
+    struct torrent *tp;
+    struct http_req *req;
+    struct evbuffer *buf;
+    enum tr_event event;
+};
+
+static void
+http_tr_free(struct http_tr_req *treq)
+{
+    evbuffer_free(treq->buf);
+    free(treq);
+}
+
+static void
+maybe_connect_to(struct torrent *tp, const char *pinfo)
+{
+    const char *pid;
+    char *ip;
+    int port;
+    size_t len;
+
+    if ((pid = benc_dget_mem(pinfo, "peer id", &len)) == NULL || len != 20)
+        return;
+
+    if (bcmp(btpd_get_peer_id(), pid, 20) == 0)
+        return;
+
+    if (net_torrent_has_peer(tp->net, pid))
+        return;
+
+    if ((ip = benc_dget_str(pinfo, "ip", NULL)) == NULL)
+        return;
+
+    port = benc_dget_int(pinfo, "port");
+    peer_create_out(tp->net, pid, ip, port);
+
+    if (ip != NULL)
+        free(ip);
+}
+
+static int
+parse_reply(struct torrent *tp, const char *content, size_t size, int parse,
+    int *interval)
+{
+    const char *buf;
+    size_t len;
+    const char *peers;
+
+    if (benc_validate(content, size) != 0)
+        goto bad_data;
+
+    if ((buf = benc_dget_mem(content, "failure reason", &len)) != NULL) {
+        btpd_log(BTPD_L_ERROR, "Tracker failure: '%.*s' for '%s'.\n",
+            (int)len, buf, torrent_name(tp));
+        return 1;
+    }
+
+    if (!parse)
+        return 0;
+
+    if (!benc_dct_chk(content, 2, BE_INT, 1, "interval", BE_ANY, 1, "peers"))
+        goto bad_data;
+
+    *interval = benc_dget_int(content, "interval");
+    if (*interval < 1)
+        goto bad_data;
+
+    peers = benc_dget_any(content, "peers");
+
+    if (benc_islst(peers)) {
+        for (peers = benc_first(peers);
+             peers != NULL && net_npeers < net_max_peers;
+             peers = benc_next(peers))
+            maybe_connect_to(tp, peers);
+    } else if (benc_isstr(peers)) {
+        peers = benc_dget_mem(content, "peers", &len);
+        for (size_t i = 0; i < len && net_npeers < net_max_peers; i += 6)
+            peer_create_out_compact(tp->net, peers + i);
+    } else
+        goto bad_data;
+
+    return 0;
+
+bad_data:
+    btpd_log(BTPD_L_ERROR, "Bad data from tracker for '%s'.\n",
+        torrent_name(tp));
+    return 1;
+}
+
+static void
+http_cb(struct http_req *req, struct http_response *res, void *arg)
+{
+    int interval;
+    struct http_tr_req *treq = arg;
+    switch (res->type) {
+    case HTTP_T_ERR:
+        btpd_log(BTPD_L_ERROR, "http request failed for '%s'.\n",
+            torrent_name(treq->tp));
+        tr_result(treq->tp, TR_RES_FAIL, -1);
+        http_tr_free(treq);
+        break;
+    case HTTP_T_DATA:
+        if (treq->buf->off + res->v.data.l > MAX_DOWNLOAD) {
+            tr_result(treq->tp, TR_RES_FAIL, -1);
+            http_tr_cancel(treq);
+            break;
+        }
+        if (evbuffer_add(treq->buf, res->v.data.p, res->v.data.l) != 0)
+            btpd_err("Out of memory.\n");
+        break;
+    case HTTP_T_DONE:
+        if (parse_reply(treq->tp, treq->buf->buffer, treq->buf->off,
+                treq->event != TR_EV_STOPPED, &interval) == 0)
+            tr_result(treq->tp, TR_RES_OK, interval);
+        else
+            tr_result(treq->tp, TR_RES_FAIL, -1);
+        http_tr_free(treq);
+        break;
+    default:
+        break;
+    }
+}
+
+struct http_tr_req *
+http_tr_req(struct torrent *tp, enum tr_event event, const char *aurl)
+{
+    char e_hash[61], e_id[61], url[512], qc;;
+    const uint8_t *peer_id = btpd_get_peer_id();
+
+    qc = (strchr(aurl, '?') == NULL) ? '?' : '&';
+
+    for (int i = 0; i < 20; i++)
+        snprintf(e_hash + i * 3, 4, "%%%.2x", tp->tl->hash[i]);
+    for (int i = 0; i < 20; i++)
+        snprintf(e_id + i * 3, 4, "%%%.2x", peer_id[i]);
+
+    snprintf(url, sizeof(url),
+        "%s%cinfo_hash=%s&peer_id=%s&key=%ld&port=%d&uploaded=%llu"
+        "&downloaded=%llu&left=%llu&compact=1%s%s",
+        aurl, qc, e_hash, e_id, tr_key, net_port,
+        tp->net->uploaded, tp->net->downloaded,
+        (long long)tp->total_length - cm_content(tp),
+        event == TR_EV_EMPTY ? "" : "&event=", m_tr_events[event]);
+
+    struct http_tr_req *treq = btpd_calloc(1, sizeof(*treq));
+    if (!http_get(&treq->req, url, "User-Agent: " BTPD_VERSION "\r\n",
+            http_cb, treq)) {
+        free(treq);
+        return NULL;
+    }
+    if ((treq->buf = evbuffer_new()) == NULL)
+        btpd_err("Out of memory.\n");
+    treq->tp = tp;
+    treq->event = event;
+    return treq;
+}
+
+void
+http_tr_cancel(struct http_tr_req *treq)
+{
+    http_cancel(treq->req);
+    http_tr_free(treq);
+}
diff --git a/btpd/tracker_req.c b/btpd/tracker_req.c
index fe31b2e..add1462 100644
--- a/btpd/tracker_req.c
+++ b/btpd/tracker_req.c
@@ -1,24 +1,16 @@
-#include <stdio.h>
 #include <string.h>
 
 #include "btpd.h"
-#include "benc.h"
 #include "subr.h"
-#include "http.h"
 #include "tracker_req.h"
 
+#define REQ_DELAY 1
 #define REQ_TIMEOUT (& (struct timeval) { 120, 0 })
 #define RETRY_WAIT (& (struct timeval) { rand_between(35, 70), 0 })
 
-enum tr_event {
-    TR_EV_STARTED,
-    TR_EV_STOPPED,
-    TR_EV_COMPLETED,
-    TR_EV_EMPTY
-};
+long tr_key;
 
-static long m_key;
-static const char *m_events[] = { "started", "stopped", "completed", "" };
+static long m_tlast_req, m_tnext_req;
 
 enum timer_type {
     TIMER_NONE,
@@ -34,102 +26,28 @@ struct tracker {
     unsigned nerrors;
     int tier, url;
     struct mi_announce *ann;
-    struct http *req;
+    void *req;
     struct event timer;
 };
 
-static void tr_send(struct torrent *tp, enum tr_event event);
-
-static void
-maybe_connect_to(struct torrent *tp, const char *pinfo)
-{
-    const char *pid;
-    char *ip;
-    int port;
-    size_t len;
-
-    if ((pid = benc_dget_mem(pinfo, "peer id", &len)) == NULL || len != 20)
-        return;
-
-    if (bcmp(btpd_get_peer_id(), pid, 20) == 0)
-        return;
-
-    if (net_torrent_has_peer(tp->net, pid))
-        return;
-
-    if ((ip = benc_dget_str(pinfo, "ip", NULL)) == NULL)
-        return;
-
-    port = benc_dget_int(pinfo, "port");
-    peer_create_out(tp->net, pid, ip, port);
-
-    if (ip != NULL)
-        free(ip);
-}
-
-
-static int
-parse_reply(struct torrent *tp, const char *content, size_t size, int parse)
-{
-    const char *buf;
-    size_t len;
-    const char *peers;
-    int interval;
-
-    if (benc_validate(content, size) != 0)
-        goto bad_data;
-
-    if ((buf = benc_dget_mem(content, "failure reason", &len)) != NULL) {
-        btpd_log(BTPD_L_ERROR, "Tracker failure: '%.*s' for '%s'.\n",
-            (int)len, buf, torrent_name(tp));
-        return 1;
-    }
-
-    if (!parse)
-        return 0;
-
-    if (!benc_dct_chk(content, 2, BE_INT, 1, "interval", BE_ANY, 1, "peers"))
-        goto bad_data;
+typedef struct _dummy *(*request_fun_t)(struct torrent *, enum tr_event,
+    const char *);
+typedef void (*cancel_fun_t)(struct _dummy *);
 
-    interval = benc_dget_int(content, "interval");
-    if (interval < 1)
-        goto bad_data;
-
-    tp->tr->interval = interval;
-    peers = benc_dget_any(content, "peers");
-
-    if (benc_islst(peers)) {
-        for (peers = benc_first(peers);
-             peers != NULL && net_npeers < net_max_peers;
-             peers = benc_next(peers))
-            maybe_connect_to(tp, peers);
-    } else if (benc_isstr(peers)) {
-        peers = benc_dget_mem(content, "peers", &len);
-        for (size_t i = 0; i < len && net_npeers < net_max_peers; i += 6)
-            peer_create_out_compact(tp->net, peers + i);
-    } else
-        goto bad_data;
-
-    return 0;
+struct tr_op {
+    int len;
+    const char *scheme;
+    request_fun_t request;
+    cancel_fun_t cancel;
+};
 
-bad_data:
-    btpd_log(BTPD_L_ERROR, "Bad data from tracker for '%s'.\n",
-        torrent_name(tp));
-    return 1;
-}
+static struct tr_op m_http_op = {
+    7, "http://", (request_fun_t)http_tr_req, (cancel_fun_t)http_tr_cancel
+};
 
-static void
-tr_set_stopped(struct torrent *tp)
-{
-    struct tracker *tr = tp->tr;
-    btpd_ev_del(&tr->timer);
-    tr->ttype = TIMER_NONE;
-    if (tr->req != NULL) {
-        http_cancel(tr->req);
-        tr->req = NULL;
-    }
-    torrent_on_tr_stopped(tp);
-}
+static struct tr_op *m_tr_ops[] = {
+    &m_http_op, NULL
+};
 
 static char *
 get_url(struct tracker *tr)
@@ -158,26 +76,82 @@ next_url(struct tracker *tr)
         tr->tier = (tr->tier + 1) % tr->ann->ntiers;
 }
 
+struct tr_op *
+get_op(struct tracker *tr)
+{
+    struct tr_op *op;
+    char *url = get_url(tr);
+    for (op = m_tr_ops[0]; op != NULL; op++)
+        if (strncasecmp(op->scheme, url, op->len) == 0)
+            return op;
+    return NULL;
+}
+
 static void
-http_cb(struct http *req, struct http_res *res, void *arg)
+tr_cancel(struct tracker *tr)
+{
+    struct tr_op *op = get_op(tr);
+    assert(op != NULL);
+    op->cancel(tr->req);
+    tr->req = NULL;
+}
+
+static void
+tr_send(struct torrent *tp, enum tr_event event)
+{
+    struct tracker *tr = tp->tr;
+    struct tr_op *op = get_op(tr);
+
+    tr->event = event;
+    if (tr->req != NULL)
+        tr_cancel(tr);
+
+    if (m_tlast_req > btpd_seconds - REQ_DELAY) {
+        m_tnext_req = max(m_tnext_req, m_tlast_req) + REQ_DELAY;
+        tr->ttype = TIMER_RETRY;
+        btpd_ev_add(&tr->timer,
+            (& (struct timeval) { m_tnext_req - btpd_seconds, 0 }));
+        return;
+    }
+
+    if ((op == NULL ||
+            (tr->req = op->request(tp, event, get_url(tr))) == NULL)) {
+        tr->ttype = TIMER_RETRY;
+        btpd_ev_add(&tr->timer, (& (struct timeval) { 20, 0 }));
+    } else {
+        m_tlast_req = btpd_seconds;
+        tr->ttype = TIMER_TIMEOUT;
+        btpd_ev_add(&tr->timer, REQ_TIMEOUT);
+    }
+}
+
+static void
+tr_set_stopped(struct torrent *tp)
+{
+    struct tracker *tr = tp->tr;
+    btpd_ev_del(&tr->timer);
+    tr->ttype = TIMER_NONE;
+    if (tr->req != NULL)
+        tr_cancel(tr);
+    torrent_on_tr_stopped(tp);
+}
+
+void
+tr_result(struct torrent *tp, enum tr_res res, int interval)
 {
-    struct torrent *tp = arg;
     struct tracker *tr = tp->tr;
-    assert(tr->ttype == TIMER_TIMEOUT);
     tr->req = NULL;
-    if (res->res == HRES_OK && parse_reply(tp, res->content, res->length,
-            tr->event != TR_EV_STOPPED) == 0) {
+    if (res == TR_RES_OK) {
         good_url(tr);
+        tr->interval = interval;
         tr->nerrors = 0;
         tr->ttype = TIMER_INTERVAL;
-        btpd_ev_add(&tr->timer, (& (struct timeval) { tr->interval, 0 }));
+        btpd_ev_add(&tr->timer, (& (struct timeval) { tr->interval, 0}));
     } else {
-        if (res->res == HRES_FAIL)
-            btpd_log(BTPD_L_BTPD, "Tracker request for '%s' failed (%s).\n",
-                torrent_name(tp), res->errmsg);
         tr->nerrors++;
         tr->ttype = TIMER_RETRY;
         btpd_ev_add(&tr->timer, RETRY_WAIT);
+        next_url(tr);
     }
     if (tr->event == TR_EV_STOPPED && (tr->nerrors == 0 || tr->nerrors >= 5))
         tr_set_stopped(tp);
@@ -197,8 +171,9 @@ timer_cb(int fd, short type, void *arg)
             tr_set_stopped(tp);
             break;
         }
-    case TIMER_RETRY:
+        tr_cancel(tr);
         next_url(tr);
+    case TIMER_RETRY:
         tr_send(tp, tr->event);
         break;
     case TIMER_INTERVAL:
@@ -209,43 +184,6 @@ timer_cb(int fd, short type, void *arg)
     }
 }
 
-static void
-tr_send(struct torrent *tp, enum tr_event event)
-{
-    long busy_secs;
-    char e_hash[61], e_id[61], qc;;
-    const uint8_t *peer_id = btpd_get_peer_id();
-
-    struct tracker *tr = tp->tr;
-    tr->event = event;
-    if (tr->ttype == TIMER_TIMEOUT)
-        http_cancel(tr->req);
-
-    if ((busy_secs = http_server_busy_time(get_url(tr), 3)) > 0) {
-        tr->ttype = TIMER_RETRY;
-        btpd_ev_add(&tr->timer, (& (struct timeval) { busy_secs, 0 }));
-        return;
-    }
-
-    tr->ttype = TIMER_TIMEOUT;
-    btpd_ev_add(&tr->timer, REQ_TIMEOUT);
-
-    qc = (strchr(get_url(tr), '?') == NULL) ? '?' : '&';
-
-    for (int i = 0; i < 20; i++)
-        snprintf(e_hash + i * 3, 4, "%%%.2x", tp->tl->hash[i]);
-    for (int i = 0; i < 20; i++)
-        snprintf(e_id + i * 3, 4, "%%%.2x", peer_id[i]);
-
-    http_get(&tr->req, http_cb, tp,
-        "%s%cinfo_hash=%s&peer_id=%s&key=%ld&port=%d&uploaded=%llu"
-        "&downloaded=%llu&left=%llu&compact=1%s%s",
-        get_url(tr), qc, e_hash, e_id, m_key, net_port,
-        tp->net->uploaded, tp->net->downloaded,
-        (long long)tp->total_length - cm_content(tp),
-        event == TR_EV_EMPTY ? "" : "&event=", m_events[event]);
-}
-
 int
 tr_create(struct torrent *tp, const char *mi)
 {
@@ -263,7 +201,7 @@ tr_kill(struct torrent *tp)
     tp->tr = NULL;
     btpd_ev_del(&tr->timer);
     if (tr->req != NULL)
-        http_cancel(tr->req);
+        tr_cancel(tr);
     mi_free_announce(tr->ann);
     free(tr);
 }
@@ -310,5 +248,5 @@ tr_errors(struct torrent *tp)
 void
 tr_init(void)
 {
-    m_key = random();
+    tr_key = random();
 }
diff --git a/btpd/tracker_req.h b/btpd/tracker_req.h
index 23cbeaa..caedeb9 100644
--- a/btpd/tracker_req.h
+++ b/btpd/tracker_req.h
@@ -1,6 +1,20 @@
 #ifndef TRACKER_REQ_H
 #define TRACKER_REQ_H
 
+enum tr_event {
+    TR_EV_STARTED,
+    TR_EV_STOPPED,
+    TR_EV_COMPLETED,
+    TR_EV_EMPTY
+};
+
+enum tr_res {
+    TR_RES_OK,
+    TR_RES_FAIL
+};
+
+extern long tr_key;
+
 int tr_create(struct torrent *tp, const char *mi);
 void tr_kill(struct torrent *tp);
 void tr_start(struct torrent *tp);
@@ -10,4 +24,12 @@ void tr_complete(struct torrent *tp);
 unsigned tr_errors(struct torrent *tp);
 int tr_active(struct torrent *tp);
 
+void tr_result(struct torrent *tp, enum tr_res res, int interval);
+
+struct http_tr_req;
+
+struct http_tr_req *http_tr_req(struct torrent *tp, enum tr_event event,
+    const char *aurl);
+void http_tr_cancel(struct http_tr_req *treq);
+
 #endif