Use a dynamic buffer for managing link messages.

diff --git a/if-bsd.c b/if-bsd.c
index 75be784c00ab70095ef7de4bc471e8b708c0f124..86748ffc6a611ad89e1f07961483169e3a4641be 100644 (file)
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -71,6 +71,8 @@
            (((struct sockaddr_in *)(void *)sa)->sin_addr).s_addr : 0
 
 static int r_fd = -1;
+static char *link_buf;
+static ssize_t link_buflen;
 
 int
 if_init(_unused struct interface *iface)
@@ -302,11 +304,10 @@ get_addrs(int type, char *cp, struct sockaddr **sa)
        }
 }
 
-#define BUFFER_LEN     2048
 int
 manage_link(int fd)
 {
-       char buffer[2048], *p, *e, *cp;
+       char *p, *e, *cp;
        char ifname[IF_NAMESIZE];
        ssize_t bytes;
        struct rt_msghdr *rtm;
@@ -315,9 +316,19 @@ manage_link(int fd)
        struct ifa_msghdr *ifam;
        struct rt rt;
        struct sockaddr *sa, *rti_info[RTAX_MAX];
+       int len;
 
        for (;;) {
-               bytes = read(fd, buffer, BUFFER_LEN);
+               if (ioctl(fd, FIONREAD, &len) == -1)
+                       return -1;
+               if (link_buflen < len) {
+                       p = realloc(link_buf, len);
+                       if (p == NULL)
+                               return -1;
+                       link_buf = p;
+                       link_buflen = len;
+               }
+               bytes = read(fd, link_buf, link_buflen);
                if (bytes == -1) {
                        if (errno == EAGAIN)
                                return 0;
@@ -325,8 +336,8 @@ manage_link(int fd)
                                continue;
                        return -1;
                }
-               e = buffer + bytes;
-               for (p = buffer; p < e; p += rtm->rtm_msglen) {
+               e = link_buf + bytes;
+               for (p = link_buf; p < e; p += rtm->rtm_msglen) {
                        rtm = (struct rt_msghdr *)(void *)p;
                        switch(rtm->rtm_type) {
                        case RTM_IFANNOUNCE: