/*----- 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 -------------------------------------------*/
y = 0;
for (j = 0; j < 8; j++) {
if ('0' <= *p && *p <= '9') x = *p - '0';
- else if ('a' <= *p && *p <= 'f') x = *p - 'a'+ 10;
- else if ('A' <= *p && *p <= 'F') x = *p - 'A'+ 10;
+ else if ('a' <= *p && *p <= 'f') x = *p - 'a' + 10;
+ else if ('A' <= *p && *p <= 'F') x = *p - 'A' + 10;
else return (-1);
y = (y << 4) | x;
p++;
const struct rtattr *rta;
const struct rtmsg *rtm;
ssize_t n, nn;
- int rc = 0;
+ int rc = -1;
static unsigned long seq = 0x48b4aec4;
/* 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;
if (rta->rta_type == RTA_GATEWAY) {
assert(RTA_PAYLOAD(rta) <= sizeof(*a));
memcpy(a, RTA_DATA(rta), RTA_PAYLOAD(rta));
- rc = 1;
+ rc = 0;
}
}
}
* this may be a proxy connection from our NAT, so remember this, and don't
* inspect the remote addresses in the TCP tables.
*/
- if (get_default_gw(q->ao->af, &s[0].addr) &&
+ if (!get_default_gw(q->ao->af, &s[0].addr) &&
q->ao->addreq(&s[0].addr, &q->s[R].addr))
gwp = 1;
}
}
-#ifdef notdef
+#ifdef DEBUG
{
/* Print the record we found. */
dstr dd = DSTR_INIT;
/* Initialize the system-specific code. */
void init_sys(void)
{
+ /* Open the NAT connection map. */
if ((natfp = fopen("/proc/net/nf_conntrack", "r")) == 0 &&
errno != ENOENT) {
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 -------------------------------------------------*/