/*----- Static variables --------------------------------------------------*/
static FILE *natfp; /* File handle for NAT table */
+static int randfd; /* File descriptor for random data */
+
+/*----- Miscellaneous system services -------------------------------------*/
+
+/* Fill the buffer at P with SZ random bytes. The buffer will be moderately
+ * large: this is intended to be a low-level interface, not a general-purpose
+ * utility.
+ */
+void fill_random(void *p, size_t sz)
+{
+ ssize_t n;
+
+ n = read(randfd, p, sz);
+ if (n < 0) fatal("error reading `/dev/urandom': %s", strerror(errno));
+ else if (n < sz) fatal("unexpected short read from `/dev/urandom'");
+}
/*----- Address-type operations -------------------------------------------*/
/* Open a netlink socket for interrogating the kernel. */
if ((fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0)
- die(1, "failed to create netlink socket: %s", strerror(errno));
+ fatal("failed to create netlink socket: %s", strerror(errno));
/* We want to read the routing table. There doesn't seem to be a good way
* to do this without just crawling through the whole thing.
rtgen->rtgen_family = af;
if (write(fd, nlmsg, nlmsg->nlmsg_len) < 0)
- die(1, "failed to send RTM_GETROUTE request: %s", strerror(errno));
+ fatal("failed to send RTM_GETROUTE request: %s", strerror(errno));
/* Now we try to parse the answer. */
for (;;) {
/* Not finished yet, so read another chunk of answer. */
if ((n = read(fd, buf, sizeof(buf))) < 0)
- die(1, "failed to read RTM_GETROUTE response: %s", strerror(errno));
+ fatal("failed to read RTM_GETROUTE response: %s", strerror(errno));
/* Start at the beginning of the response. */
nlmsg = (struct nlmsghdr *)buf;
die(1, "failed to open `/proc/net/nf_conntrack' for reading: %s",
strerror(errno));
}
+
+ /* Open the random data source. */
+ if ((randfd = open("/dev/urandom", O_RDONLY)) < 0) {
+ die(1, "failed to open `/dev/urandom' for reading: %s",
+ strerror(errno));
+ }
}
/*----- That's all, folks -------------------------------------------------*/