rp-pppoe: allow MTU to be increased up to 1500

[ppp.git] / pppd / plugins / rp-pppoe / plugin.c

diff --git a/pppd/plugins/rp-pppoe/plugin.c b/pppd/plugins/rp-pppoe/plugin.c
index e94494b96cc08587e05def9f7f1ec5023dc8bd9a..97011aaab938cc5066281846113ebf1bac32921a 100644 (file)
--- a/pppd/plugins/rp-pppoe/plugin.c
+++ b/pppd/plugins/rp-pppoe/plugin.c
@@ -108,8 +108,6 @@ PPPOEInitDevice(void)
        novm("PPPoE session data");
     }
     memset(conn, 0, sizeof(PPPoEConnection));
-    conn->acName = acName;
-    conn->serviceName = pppd_pppoe_service;
     conn->ifName = devnam;
     conn->discoverySocket = -1;
     conn->sessionSocket = -1;
@@ -132,7 +130,34 @@ static int
 PPPOEConnectDevice(void)
 {
     struct sockaddr_pppox sp;
+    struct ifreq ifr;
+    int s;
+
+    /* Restore configuration */
+    lcp_allowoptions[0].mru = conn->mtu;
+    lcp_wantoptions[0].mru = conn->mru;
+
+    /* Update maximum MRU */
+    s = socket(AF_INET, SOCK_DGRAM, 0);
+    if (s < 0) {
+       error("Can't get MTU for %s: %m", conn->ifName);
+       goto errout;
+    }
+    strncpy(ifr.ifr_name, conn->ifName, sizeof(ifr.ifr_name));
+    if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
+       error("Can't get MTU for %s: %m", conn->ifName);
+       close(s);
+       goto errout;
+    }
+    close(s);
 
+    if (lcp_allowoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD)
+       lcp_allowoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
+    if (lcp_wantoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD)
+       lcp_wantoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
+
+    conn->acName = acName;
+    conn->serviceName = pppd_pppoe_service;
     strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
     if (existingSession) {
        unsigned int mac[ETH_ALEN];
@@ -163,6 +188,7 @@ PPPOEConnectDevice(void)
        error("Failed to create PPPoE socket: %m");
        goto errout;
     }
+
     sp.sa_family = AF_PPPOX;
     sp.sa_protocol = PX_PROTO_OE;
     sp.sa_addr.pppoe.sid = conn->session;
@@ -381,6 +407,10 @@ void pppoe_check_options(void)
     if (lcp_wantoptions[0].mru > MAX_PPPOE_MTU)
        lcp_wantoptions[0].mru = MAX_PPPOE_MTU;
 
+    /* Save configuration */
+    conn->mtu = lcp_allowoptions[0].mru;
+    conn->mru = lcp_wantoptions[0].mru;
+
     ccp_allowoptions[0].deflate = 0;
     ccp_wantoptions[0].deflate = 0;