Move dhcp6's read lease code into dhcp-common.

While here, fix MTU min/max.

diff --git a/dhcp-common.c b/dhcp-common.c
index d8028ce74e7a3d9468ffe2939820121fff761dbd..74336fd613861148cdec8e4fc0dce9d0e0dbcd97 100644 (file)
--- a/dhcp-common.c
+++ b/dhcp-common.c
@@ -1056,3 +1056,39 @@ dhcp_zero_index(struct dhcp_opt *opt)
        for (i = 0, o = opt->encopts; i < opt->encopts_len; i++, o++)
                dhcp_zero_index(o);
 }
+
+size_t
+dhcp_read_lease_fd(int fd, uint8_t **lease)
+{
+       uint8_t *buf, *nbuf;
+       size_t len, new_len;
+       ssize_t bytes;
+
+       if ((buf = malloc(BUFSIZ)) == NULL)
+               goto out;
+
+       len = 0;
+       for (;;) {
+               bytes = read(fd, buf + len, BUFSIZ);
+               if (bytes == -1)
+                       break;
+               if (bytes < BUFSIZ) {
+                       *lease = buf;
+                       return len + (size_t)bytes;
+               }
+               new_len = len + (BUFSIZ * 2);
+               if (new_len > UINT32_MAX || new_len < len) {
+                       errno = E2BIG;
+                       break;
+               }
+               if ((nbuf = realloc(buf, new_len)) == NULL)
+                       break;
+               buf = nbuf;
+               len += BUFSIZ;
+       }
+
+       free(buf);
+out:
+       *lease = NULL;
+       return 0;
+}

diff --git a/dhcp-common.h b/dhcp-common.h
index f576a172aa01cff42b6e6d3ad295b3561138b66d..61eccf18fe5e40fc383867cda9341c86aad5ce8d 100644 (file)
--- a/dhcp-common.h
+++ b/dhcp-common.h
@@ -37,8 +37,9 @@
 #include "dhcpcd.h"
 
 /* Max MTU - defines dhcp option length */
-#define        MTU_MAX                 1500
-#define        MTU_MIN                  576
+#define        IP_UDP_SIZE               28
+#define        MTU_MAX                 1500 - IP_UDP_SIZE
+#define        MTU_MIN                  576 + IP_UDP_SIZE
 
 #define        OT_REQUEST              (1 << 0)
 #define        OT_UINT8                (1 << 1)
@@ -117,5 +118,6 @@ size_t dhcp_envoption(struct dhcpcd_ctx *,
     const uint8_t *, size_t, struct dhcp_opt **),
     const uint8_t *od, size_t ol);
 void dhcp_zero_index(struct dhcp_opt *);
+size_t dhcp_read_lease_fd(int, uint8_t **);
 
 #endif

diff --git a/dhcp6.c b/dhcp6.c
index d5457e3749e8226819c8e24a2dbc233d51f29d3f..3c1f060f34cb0af46e3cd25e6a2f35616d843da9 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2162,18 +2162,16 @@ dhcp6_readlease(struct interface *ifp, int validate)
        struct dhcp6_state *state;
        struct stat st;
        int fd;
-       ssize_t bytes;
+       uint8_t *lease;
        const struct dhcp6_option *o;
        struct timespec acquired;
        time_t now;
        int retval;
-       size_t newlen;
-       void *newnew;
        bool fd_opened;
 
        state = D6_STATE(ifp);
        if (state->leasefile[0] == '\0') {
-               logger(ifp->ctx, LOG_DEBUG, "reading standard input");
+               logger(ifp->ctx, LOG_DEBUG, "reading standard input");
                fd = fileno(stdin);
                fd_opened = false;
        } else {
@@ -2188,39 +2186,13 @@ dhcp6_readlease(struct interface *ifp, int validate)
        }
        if (fd == -1)
                return -1;
-       state->new_len = 0;
-       if ((state->new = malloc(BUFSIZ)) == NULL) {
-               if (fd_opened)
-                       close(fd);
-               return -1;
-       }
        retval = -1;
-       /* DHCPv6 messages have no real maximum size.
-        * As we could be reading from stdin, we loop like so.
-        * state->new_len refers to the buffer position,
-        * but the buffer itself always BUFSIZ bigger. */
-       for (;;) {
-               bytes = read(fd, (char *)state->new + state->new_len, BUFSIZ);
-               if (bytes == -1)
-                       break;
-               if (bytes < BUFSIZ) {
-                       state->new_len += (size_t)bytes;
-                       retval = 0;
-                       break;
-               }
-               newlen = state->new_len + (BUFSIZ * 2);
-               if (newlen > UINT32_MAX || newlen < state->new_len) {
-                       errno = E2BIG;
-                       break;
-               }
-               if ((newnew = realloc(state->new, newlen)) == NULL)
-                       break;
-               state->new = newnew;
-               state->new_len += BUFSIZ;
-       }
+       lease = NULL;
+       state->new_len = dhcp_read_lease_fd(fd, &lease);
+       state->new = (struct dhcp6_message *)lease;
        if (fd_opened)
                close(fd);
-       if (retval == -1)
+       if (state->new_len == 0)
                goto ex;
 
        if (ifp->ctx->options & DHCPCD_DUMPLEASE ||
@@ -2234,7 +2206,6 @@ dhcp6_readlease(struct interface *ifp, int validate)
                goto auth;
        }
 
-       retval = -1;
        clock_gettime(CLOCK_MONOTONIC, &acquired);
        if ((now = time(NULL)) == -1)
                goto ex;