Fix dumping DHCPv6 leases.

diff --git a/dhcp6.c b/dhcp6.c
index f3fa9cdb36cfc37205d6560b0a1cafdfc77be16b..5caf0f34a713c426b6cfbee9643770eac788a5bc 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2185,6 +2185,7 @@ dhcp6_readlease(struct interface *ifp, int validate)
        struct timespec acquired;
        time_t now;
        int retval;
+       void *newnew;
 
        state = D6_STATE(ifp);
        if (state->leasefile[0] == '\0')
@@ -2195,23 +2196,38 @@ dhcp6_readlease(struct interface *ifp, int validate)
                logger(ifp->ctx, LOG_DEBUG, "%s: reading lease `%s'",
                    ifp->name, state->leasefile);
        }
-       if (st.st_size > UINT32_MAX) {
-               errno = E2BIG;
-               return -1;
-       }
        if (state->leasefile[0] == '\0')
                fd = fileno(stdin);
        else
                fd = open(state->leasefile, O_RDONLY);
        if (fd == -1)
                return -1;
-       if ((state->new = malloc((size_t)st.st_size)) == NULL)
+       state->new_len = 0;
+       if ((state->new = malloc(BUFSIZ)) == NULL)
                return -1;
        retval = -1;
-       state->new_len = (size_t)st.st_size;
-       bytes = read(fd, state->new, state->new_len);
+       /* DHCPv6 messages have no real maximum size.
+        * As we could be reading from stdin, we loop like so. */
+       for (;;) {
+               bytes = read(fd, state->new + state->new_len, BUFSIZ);
+               if (bytes == -1)
+                       break;
+               if (bytes < BUFSIZ) {
+                       state->new_len += (size_t)bytes;
+                       retval = 0;
+                       break;
+               }
+               state->new_len += BUFSIZ;
+               if (state->new_len > UINT32_MAX) {
+                       errno = E2BIG;
+                       break;
+               }
+               if ((newnew = realloc(state->new, state->new_len)) == NULL)
+                       break;
+               state->new = newnew;
+       }
        close(fd);
-       if (bytes != (ssize_t)state->new_len)
+       if (retval == -1)
                goto ex;
 
        /* If not validating IA's and if they have expired,
@@ -2221,8 +2237,10 @@ dhcp6_readlease(struct interface *ifp, int validate)
                goto auth;
        }
 
-       if ((now = time(NULL)) == -1)
+       if ((now = time(NULL)) == -1) {
+               retval = 1;
                goto ex;
+       }
 
        clock_gettime(CLOCK_MONOTONIC, &acquired);
        acquired.tv_sec -= now - st.st_mtime;
@@ -2230,11 +2248,14 @@ dhcp6_readlease(struct interface *ifp, int validate)
        /* Check to see if the lease is still valid */
        fd = dhcp6_validatelease(ifp, state->new, state->new_len, NULL,
            &acquired);
-       if (fd == -1)
+       if (fd == -1) {
+               retval = 1;
                goto ex;
+       }
 
        if (!(ifp->ctx->options & DHCPCD_DUMPLEASE) &&
-           state->expire != ND6_INFINITE_LIFETIME)
+           state->expire != ND6_INFINITE_LIFETIME &&
+           state->leasefile[0] != '\0')
        {
                if ((time_t)state->expire < now - st.st_mtime) {
                        logger(ifp->ctx,
@@ -2246,7 +2267,6 @@ dhcp6_readlease(struct interface *ifp, int validate)
        }
 
 auth:
-
        retval = 0;
        /* Authenticate the message */
        o = dhcp6_getmoption(D6_OPTION_AUTH, state->new, state->new_len);