Torrents that were active when btpd was last killed will now be automatically

started when btpd starts. The new '--empty-start' option turns this off.

btpd/Makefile.am

@@ -1,5 +1,6 @@
 bin_PROGRAMS=btpd
 btpd_SOURCES=\
+        active.c active.h\
 	btpd.c btpd.h\
 	cli_if.c content.c content.h\
 	download.c download_subr.c download.h\

btpd/active.c

@@ -0,0 +1,101 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <string.h>
+#include <unistd.h>
+
+#include "btpd.h"
+
+void
+active_add(const uint8_t *hash)
+{
+    FILE *fp;
+    if ((fp = fopen("active", "a")) == NULL) {
+        btpd_log(BTPD_L_ERROR, "couldn't open file 'active' (%s).\n",
+            strerror(errno));
+        return;
+    }
+    fwrite(hash, 20, 1, fp);
+    fclose(fp);
+}
+
+static void
+active_del_pos(FILE *fp, long pos, off_t *size)
+{
+    uint8_t ehash[20];
+    fseek(fp, -20, SEEK_END);
+    fread(ehash, 20, 1, fp);
+    fseek(fp, pos, SEEK_SET);
+    fwrite(ehash, 20, 1, fp);
+    fflush(fp);
+    *size -= 20;
+    ftruncate(fileno(fp), *size);
+}
+
+void
+active_del(const uint8_t *hash)
+{
+    FILE *fp;
+    long pos;
+    struct stat sb;
+    uint8_t buf[20];
+
+    if ((fp = fopen("active", "r+")) == NULL) {
+        btpd_log(BTPD_L_ERROR, "couldn't open file 'active' (%s).\n",
+            strerror(errno));
+        return;
+    }
+
+    if (fstat(fileno(fp), &sb) != 0) {
+        btpd_log(BTPD_L_ERROR, "couldn't stat file 'active' (%s).\n",
+            strerror(errno));
+        goto close;
+    }
+
+    pos = 0;
+    while (fread(buf, 20, 1, fp) == 1) {
+        if (bcmp(buf, hash, 20) == 0) {
+            active_del_pos(fp, pos, &sb.st_size);
+            break;
+        }
+        pos += 20;
+    }
+close:
+    fclose(fp);
+}
+
+void
+active_start(void)
+{
+    FILE *fp;
+    long pos;
+    struct stat sb;
+    uint8_t hash[20];
+
+    if ((fp = fopen("active", "r+")) == NULL)
+        return;
+
+    if (fstat(fileno(fp), &sb) != 0) {
+        btpd_log(BTPD_L_ERROR, "Couldn't stat file 'active' (%s).\n",
+            strerror(errno));
+        goto close;
+    }
+
+    pos = 0;
+    while (fread(hash, sizeof(hash), 1, fp) == 1) {
+        if (torrent_get(hash) == NULL)
+            if (torrent_start(hash) != 0) {
+                active_del_pos(fp, pos, &sb.st_size);
+                fseek(fp, pos, SEEK_SET);
+            }
+        pos += 20;
+    }
+close:
+    fclose(fp);
+}
+
+void
+active_clear(void)
+{
+    unlink("active");
+}

btpd/active.h

@@ -0,0 +1,9 @@
+#ifndef BTPD_ACTIVE_H
+#define BTPD_ACTIVE_H
+
+void active_add(const uint8_t *hash);
+void active_del(const uint8_t *hash);
+void active_clear(void);
+void active_start(void);
+
+#endif

btpd/btpd.c

@@ -28,6 +28,7 @@
 
 #include "btpd.h"
 #include "http.h"
+#include "active.h"
 
 static uint8_t m_peer_id[20];
 static struct event m_sigint;
@@ -209,4 +210,9 @@ btpd_init(void)
     btpd_ev_add(&m_sigterm, NULL);
     evtimer_set(&m_heartbeat, heartbeat_cb, NULL);
     btpd_ev_add(&m_heartbeat, (& (struct timeval) { 1, 0 }));
+
+    if (!empty_start)
+        active_start();
+    else
+        active_clear();
 }

btpd/cli_if.c

@@ -12,6 +12,7 @@
 #include <unistd.h>
 
 #include "btpd.h"
+#include "active.h"
 #include "tracker_req.h"
 
 struct cli {
@@ -121,8 +122,12 @@ cmd_add(struct cli *cli, int argc, const char *args)
         code = IPC_ERROR;
         goto out;
     }
-    if (torrent_start(hash) != 0)
+    if (torrent_start(hash) != 0) {
         code = IPC_ERROR;
+        goto out;
+    }
+
+    active_add(hash);
 
 out:
     if (content != NULL)
@@ -149,8 +154,10 @@ cmd_del(struct cli *cli, int argc, const char *args)
     // Stopping a torrent may trigger exit so we need to reply before.
     int ret = write_code_buffer(cli, IPC_OK);
     struct torrent *tp = torrent_get(hash);
-    if (tp != NULL)
+    if (tp != NULL) {
         torrent_stop(tp);
+        active_del(hash);
+    }
     return ret;
 }
 

btpd/main.c

@@ -96,6 +96,9 @@ usage(void)
         "-d dir\n"
         "\tThe directory in which to run btpd. Default is '$HOME/.btpd'.\n"
         "\n"
+        "--empty-start\n"
+        "\tStart btpd without any active torrents.\n"
+        "\n"
         "--help\n"
         "\tShow this text.\n"
         "\n"
@@ -144,6 +147,7 @@ static struct option longopts[] = {
     { "no-daemon", no_argument,         &longval,       6 },
     { "logfile", required_argument,     &longval,       7 },
     { "ipcprot", required_argument,     &longval,       8 },
+    { "empty-start", no_argument,       &longval,       9 },
     { "help",   no_argument,            &longval,       128 },
     { NULL,     0,                      NULL,           0 }
 };
@@ -192,6 +196,9 @@ main(int argc, char **argv)
             case 8:
                 ipcprot = strtol(optarg, NULL, 8);
                 break;
+            case 9:
+                empty_start = 1;
+                break;
             default:
                 usage();
             }

btpd/opts.c

@@ -13,3 +13,4 @@ unsigned net_bw_limit_out;
 int net_port = 6881;
 off_t cm_alloc_size = 2048 * 1024;
 int ipcprot = 0600;
+int empty_start = 0;

btpd/opts.h

@@ -10,5 +10,6 @@ extern unsigned net_bw_limit_out;
 extern int net_port;
 extern off_t cm_alloc_size;
 extern int ipcprot;
+extern int empty_start;
 
 #endif