dnsd: fix a number of bugs. Ideas by Ming-Ching Tiew (mctiew AT yahoo.com)

[oweals/busybox.git] / networking / udhcp / files.c

diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 64edcbb256d855fce2c125a123172c1b0e3a86dc..a061a9c9bb469e0ef91c370c3b7e1dd2d4edfc19 100644 (file)
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -36,6 +36,7 @@ static int read_ip(const char *line, void *arg)
        return 1;
 }
 
+
 static int read_mac(const char *line, void *arg)
 {
        return NULL == ether_aton_r(line, (struct ether_addr *)arg);
@@ -362,7 +363,7 @@ void FAST_FUNC write_leases(void)
                if (leases[i].yiaddr == 0)
                        continue;
 
-               /* screw with the time in the struct, for easier writing */
+               /* Screw with the time in the struct, for easier writing */
                tmp_time = leases[i].expires;
 
                leases[i].expires -= curr;
@@ -374,7 +375,7 @@ void FAST_FUNC write_leases(void)
                 * we lose some leases on restart. Oh well. */
                full_write(fd, &leases[i], sizeof(leases[i]));
 
-               /* then restore it when done */
+               /* Then restore it when done */
                leases[i].expires = tmp_time;
        }
        close(fd);
@@ -390,10 +391,10 @@ void FAST_FUNC write_leases(void)
 
 void FAST_FUNC read_leases(const char *file)
 {
-       int fd;
-       unsigned i;
        struct dhcpOfferedAddr lease;
-       int64_t written_at, curr;
+       int64_t written_at, time_passed;
+       int fd;
+       USE_UDHCP_DEBUG(unsigned i;)
 
        fd = open_or_warn(file, O_RDONLY);
        if (fd < 0)
@@ -402,27 +403,28 @@ void FAST_FUNC read_leases(const char *file)
        if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
                goto ret;
        written_at = ntoh64(written_at);
-       curr = time(NULL);
-       if (curr < written_at)
-               written_at = curr; /* lease file from future! :) */
-
-       i = 0;
-       while (i < server_config.max_leases
-        && full_read(fd, &lease, sizeof(lease)) == sizeof(lease)
-       ) {
+
+       time_passed = time(NULL) - written_at;
+       /* Strange written_at, or lease file from old version of udhcpd
+        * which had no "written_at" field? */
+       if ((uint64_t)time_passed > 12 * 60 * 60)
+               goto ret;
+
+       USE_UDHCP_DEBUG(i = 0;)
+       while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
                /* ADDME: what if it matches some static lease? */
                uint32_t y = ntohl(lease.yiaddr);
                if (y >= server_config.start_ip && y <= server_config.end_ip) {
-                       int64_t expires = ntohl(lease.expires) + written_at - curr;
+                       signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
                        if (expires <= 0)
                                continue;
                        /* NB: add_lease takes "relative time", IOW,
                         * lease duration, not lease deadline. */
-                       if (!(add_lease(lease.chaddr, lease.yiaddr, expires))) {
+                       if (!(add_lease(lease.chaddr, lease.yiaddr, expires, lease.hostname))) {
                                bb_error_msg("too many leases while loading %s", file);
                                break;
                        }
-                       i++;
+                       USE_UDHCP_DEBUG(i++;)
                }
        }
        DEBUG("Read %d leases", i);