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-rw-r--r--net/ipv4/cipso_ipv4.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index e13d6dbb66a..23768b9d6b6 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1810,6 +1810,80 @@ socket_setattr_failure:
}
/**
+ * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
+ * @sk: the socket
+ *
+ * Description:
+ * Removes the CIPSO option from a socket, if present.
+ *
+ */
+void cipso_v4_sock_delattr(struct sock *sk)
+{
+ u8 hdr_delta;
+ struct ip_options *opt;
+ struct inet_sock *sk_inet;
+
+ sk_inet = inet_sk(sk);
+ opt = sk_inet->opt;
+ if (opt == NULL || opt->cipso == 0)
+ return;
+
+ if (opt->srr || opt->rr || opt->ts || opt->router_alert) {
+ u8 cipso_len;
+ u8 cipso_off;
+ unsigned char *cipso_ptr;
+ int iter;
+ int optlen_new;
+
+ cipso_off = opt->cipso - sizeof(struct iphdr);
+ cipso_ptr = &opt->__data[cipso_off];
+ cipso_len = cipso_ptr[1];
+
+ if (opt->srr > opt->cipso)
+ opt->srr -= cipso_len;
+ if (opt->rr > opt->cipso)
+ opt->rr -= cipso_len;
+ if (opt->ts > opt->cipso)
+ opt->ts -= cipso_len;
+ if (opt->router_alert > opt->cipso)
+ opt->router_alert -= cipso_len;
+ opt->cipso = 0;
+
+ memmove(cipso_ptr, cipso_ptr + cipso_len,
+ opt->optlen - cipso_off - cipso_len);
+
+ /* determining the new total option length is tricky because of
+ * the padding necessary, the only thing i can think to do at
+ * this point is walk the options one-by-one, skipping the
+ * padding at the end to determine the actual option size and
+ * from there we can determine the new total option length */
+ iter = 0;
+ optlen_new = 0;
+ while (iter < opt->optlen)
+ if (opt->__data[iter] != IPOPT_NOP) {
+ iter += opt->__data[iter + 1];
+ optlen_new = iter;
+ } else
+ iter++;
+ hdr_delta = opt->optlen;
+ opt->optlen = (optlen_new + 3) & ~3;
+ hdr_delta -= opt->optlen;
+ } else {
+ /* only the cipso option was present on the socket so we can
+ * remove the entire option struct */
+ sk_inet->opt = NULL;
+ hdr_delta = opt->optlen;
+ kfree(opt);
+ }
+
+ if (sk_inet->is_icsk && hdr_delta > 0) {
+ struct inet_connection_sock *sk_conn = inet_csk(sk);
+ sk_conn->icsk_ext_hdr_len -= hdr_delta;
+ sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
+ }
+}
+
+/**
* cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
* @cipso: the CIPSO v4 option
* @secattr: the security attributes