From 078e2f60d613eda13cc69bb6bdb1f5c322d4a6ef Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Tue, 12 May 2009 18:00:47 +0000
Subject: [PATCH] bug #26487: Added ip_output_if_opt that can add IP options to
 the IP header (used by igmp_ip_output_if)

---
 CHANGELOG                  |  6 +++-
 src/core/ipv4/igmp.c       | 64 ++++----------------------------------
 src/core/ipv4/ip.c         | 40 ++++++++++++++++++++++--
 src/include/ipv4/lwip/ip.h |  8 +++++
 4 files changed, 57 insertions(+), 61 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 4239dcad..92ed75e1 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -47,7 +47,7 @@ HISTORY
 
   2009-04-15 Simon Goldschmidt
   * dhcp.c: patch #6763: Global DHCP XID can be redefined to something more unique
-²
+
   2009-03-31 Kieran Mansley
   * tcp.c, tcp_out.c, tcp_in.c, sys.h, tcp.h, opts.h: add support for
     TCP timestamp options, off by default.  Rework tcp_enqueue() to
@@ -109,6 +109,10 @@ HISTORY
 
   ++ Bugfixes:
 
+  2009-05-12 Simon Goldschmidt
+  * ip.h, ip.c, igmp.c: bug #26487: Added ip_output_if_opt that can add IP options
+    to the IP header (used by igmp_ip_output_if)
+
   2009-05-06 Simon Goldschmidt
   * inet_chksum.c: On little endian architectures, use LWIP_PLATFORM_HTONS (if
     defined) for SWAP_BYTES_IN_WORD to speed up checksumming.
diff --git a/src/core/ipv4/igmp.c b/src/core/ipv4/igmp.c
index 33ce5fc3..062500aa 100644
--- a/src/core/ipv4/igmp.c
+++ b/src/core/ipv4/igmp.c
@@ -667,7 +667,8 @@ igmp_stop_timer(struct igmp_group *group)
 void
 igmp_delaying_member( struct igmp_group *group, u8_t maxresp)
 {
-  if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) || ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && (maxresp > group->timer))) {
+  if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) ||
+    ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) && (maxresp > group->timer))) {
     igmp_start_timer(group, (maxresp)/2);
     group->group_state = IGMP_GROUP_DELAYING_MEMBER;
   }
@@ -696,64 +697,11 @@ err_t
 igmp_ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
                   u8_t ttl, u8_t proto, struct netif *netif)
 {
-  static u16_t    ip_id = 0;
-  struct ip_hdr * iphdr = NULL;
-  u16_t *         ra    = NULL;
-
-  /* First write in the "router alert" */
-  if (pbuf_header(p, ROUTER_ALERTLEN)) {
-    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
-    return ERR_BUF;
-  }
-
   /* This is the "router alert" option */
-  ra    = p->payload;
+  u16_t ra[2];
   ra[0] = htons (ROUTER_ALERT);
   ra[1] = 0x0000; /* Router shall examine packet */
-
-  /* now the normal ip header */
-  if (pbuf_header(p, IP_HLEN)) {
-    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: not enough room for IP header in pbuf\n"));
-    return ERR_BUF;
-  }
-
-  iphdr = p->payload;
-
-  /* Should the IP header be generated or is it already included in p? */
-  if (dest != IP_HDRINCL) {
-    /** @todo should be shared with ip.c - ip_output_if */
-    IPH_TTL_SET(iphdr, ttl);
-    IPH_PROTO_SET(iphdr, proto);
-
-    ip_addr_set(&(iphdr->dest), dest);
-
-    IPH_VHLTOS_SET(iphdr, 4, ((IP_HLEN + ROUTER_ALERTLEN) / 4), 0/*tos*/);
-    IPH_LEN_SET(iphdr, htons(p->tot_len));
-    IPH_OFFSET_SET(iphdr, 0);
-    IPH_ID_SET(iphdr, htons(ip_id));
-    ++ip_id;
-
-    if (ip_addr_isany(src)) {
-      ip_addr_set(&(iphdr->src), &(netif->ip_addr));
-    } else {
-      ip_addr_set(&(iphdr->src), src);
-    }
-
-    IPH_CHKSUM_SET(iphdr, 0);
-#if CHECKSUM_GEN_IP
-    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, (IP_HLEN + ROUTER_ALERTLEN)));
-#endif
-  } else {
-    dest = &(iphdr->dest);
-  }
-
-#if IP_DEBUG
-  ip_debug_print(p);
-#endif
-
-  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_ip_output_if: sending to if %p\n", netif));
-
-  return netif->output(netif, p, dest);
+  return ip_output_if_opt(p, src, dest, ttl, 0, proto, netif, ra, ROUTER_ALERTLEN);
 }
 
 /**
@@ -797,10 +745,10 @@ igmp_send(struct igmp_group *group, u8_t type)
       igmp->igmp_checksum = 0;
       igmp->igmp_checksum = inet_chksum( igmp, IGMP_MINLEN);
 
-      igmp_ip_output_if( p, &src, dest, IGMP_TTL, IP_PROTO_IGMP, group->interface);
+      igmp_ip_output_if(p, &src, dest, IGMP_TTL, IP_PROTO_IGMP, group->interface);
     }
 
-    pbuf_free (p);
+    pbuf_free(p);
   } else {
     LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n"));
   }
diff --git a/src/core/ipv4/ip.c b/src/core/ipv4/ip.c
index 6ca24f5a..f2545040 100644
--- a/src/core/ipv4/ip.c
+++ b/src/core/ipv4/ip.c
@@ -518,6 +518,21 @@ ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
              u8_t ttl, u8_t tos,
              u8_t proto, struct netif *netif)
 {
+#if IP_OPTIONS_SEND
+  return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
+}
+
+/**
+ * Same as ip_output_if() but with the possibility to include IP options:
+ *
+ * @ param ip_options pointer to the IP options, copied into the IP header
+ * @ param optlen length of ip_options
+ */
+err_t ip_output_if_opt(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
+       u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
+       u16_t optlen)
+{
+#endif /* IP_OPTIONS_SEND */
   struct ip_hdr *iphdr;
   static u16_t ip_id = 0;
 
@@ -525,6 +540,27 @@ ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
 
   /* Should the IP header be generated or is it already included in p? */
   if (dest != IP_HDRINCL) {
+    u16_t ip_hlen = IP_HLEN;
+#if IP_OPTIONS_SEND
+    u16_t optlen_aligned = 0;
+    if (optlen != 0) {
+      /* round up to a multiple of 4 */
+      optlen_aligned = ((optlen + 3) & ~3);
+      ip_hlen += optlen_aligned;
+      /* First write in the IP options */
+      if (pbuf_header(p, optlen_aligned)) {
+        LWIP_DEBUGF(IP_DEBUG | 2, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
+        IP_STATS_INC(ip.err);
+        snmp_inc_ipoutdiscards();
+        return ERR_BUF;
+      }
+      MEMCPY(p->payload, ip_options, optlen);
+      if (optlen < optlen_aligned) {
+        /* zero the remaining bytes */
+        memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
+      }
+    }
+#endif /* IP_OPTIONS_SEND */
     /* generate IP header */
     if (pbuf_header(p, IP_HLEN)) {
       LWIP_DEBUGF(IP_DEBUG | 2, ("ip_output: not enough room for IP header in pbuf\n"));
@@ -543,7 +579,7 @@ ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
 
     ip_addr_set(&(iphdr->dest), dest);
 
-    IPH_VHLTOS_SET(iphdr, 4, IP_HLEN / 4, tos);
+    IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
     IPH_LEN_SET(iphdr, htons(p->tot_len));
     IPH_OFFSET_SET(iphdr, 0);
     IPH_ID_SET(iphdr, htons(ip_id));
@@ -557,7 +593,7 @@ ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
 
     IPH_CHKSUM_SET(iphdr, 0);
 #if CHECKSUM_GEN_IP
-    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
+    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
 #endif
   } else {
     /* IP header already included in p */
diff --git a/src/include/ipv4/lwip/ip.h b/src/include/ipv4/lwip/ip.h
index 88364cf5..9b6f5bef 100644
--- a/src/include/ipv4/lwip/ip.h
+++ b/src/include/ipv4/lwip/ip.h
@@ -43,6 +43,9 @@
 extern "C" {
 #endif
 
+/** Currently, the function ip_output_if_opt() is only used with IGMP */
+#define IP_OPTIONS_SEND   LWIP_IGMP
+
 #define ip_init() /* Compatibility define, not init needed. */
 struct netif *ip_route(struct ip_addr *dest);
 err_t ip_input(struct pbuf *p, struct netif *inp);
@@ -55,6 +58,11 @@ err_t ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
 err_t ip_output_hinted(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
        u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint);
 #endif /* LWIP_NETIF_HWADDRHINT */
+#if IP_OPTIONS_SEND
+err_t ip_output_if_opt(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
+       u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
+       u16_t optlen);
+#endif /* IP_OPTIONS_SEND */
 struct netif *ip_current_netif();
 const struct ip_hdr *ip_current_header();