diff mbox

[PATCHv9,02/10] slirp: Adding ICMPv6 error sending

Message ID a6425369450ce7a2e47cadc2e6f714bcb42cd190.1456168872.git.samuel.thibault@ens-lyon.org (mailing list archive)
State New, archived
Headers show

Commit Message

Samuel Thibault Feb. 22, 2016, 7:28 p.m. UTC 
From: Yann Bordenave <meow@meowstars.org>

Disambiguation : icmp_error is renamed into icmp_send_error, since it
doesn't manage errors, but only sends ICMP Error messages.

Adding icmp6_send_error to send ICMPv6 Error messages. This function is
simpler than the v4 version.
Adding some calls in various functions to send ICMP errors, when a
received packet is too big, or when its hop limit is 0.

Signed-off-by: Yann Bordenave <meow@meowstars.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 slirp/ip6_icmp.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 slirp/ip6_icmp.h  | 10 +++++++++
 slirp/ip6_input.c | 13 ++++++-----
 slirp/ip_icmp.c   | 12 +++++------
 slirp/ip_icmp.h   |  4 ++--
 slirp/ip_input.c  |  8 +++----
 slirp/socket.c    |  4 ++--
 slirp/tcp_input.c |  2 +-
 slirp/udp.c       |  3 ++-
 9 files changed, 99 insertions(+), 21 deletions(-)

Comments

Jason Wang March 7, 2016, 6:55 a.m. UTC | #1 
On 02/23/2016 03:28 AM, Samuel Thibault wrote:
> From: Yann Bordenave <meow@meowstars.org>
>
> Disambiguation : icmp_error is renamed into icmp_send_error, since it
> doesn't manage errors, but only sends ICMP Error messages.
>
> Adding icmp6_send_error to send ICMPv6 Error messages. This function is
> simpler than the v4 version.
> Adding some calls in various functions to send ICMP errors, when a
> received packet is too big, or when its hop limit is 0.

Let's split this into two patches to avoid mixing renaming and new
function introduction.
Samuel Thibault March 7, 2016, 1:34 p.m. UTC | #2 
Jason Wang, on Mon 07 Mar 2016 14:55:52 +0800, wrote:
> On 02/23/2016 03:28 AM, Samuel Thibault wrote:
> > From: Yann Bordenave <meow@meowstars.org>
> >
> > Disambiguation : icmp_error is renamed into icmp_send_error, since it
> > doesn't manage errors, but only sends ICMP Error messages.
> >
> > Adding icmp6_send_error to send ICMPv6 Error messages. This function is
> > simpler than the v4 version.
> > Adding some calls in various functions to send ICMP errors, when a
> > received packet is too big, or when its hop limit is 0.
> 
> Let's split this into two patches to avoid mixing renaming and new
> function introduction.

Ok, done so.

Samuel
diff mbox

Patch

diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
index 029d297..1cc65db 100644
--- a/slirp/ip6_icmp.c
+++ b/slirp/ip6_icmp.c
@@ -59,6 +59,70 @@  static void icmp6_send_echoreply(struct mbuf *m, Slirp *slirp, struct ip6 *ip,
     ip6_output(NULL, t, 0);
 }
 
+void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
+{
+    Slirp *slirp = m->slirp;
+    struct mbuf *t;
+    struct ip6 *ip = mtod(m, struct ip6 *);
+
+    char addrstr[INET6_ADDRSTRLEN];
+    DEBUG_CALL("icmp_send_error");
+    DEBUG_ARGS((dfd, " type = %d, code = %d\n", type, code));
+
+    if (IN6_IS_ADDR_MULTICAST(&ip->ip_src) ||
+            IN6_IS_ADDR_UNSPECIFIED(&ip->ip_src)) {
+        /* TODO icmp error? */
+        return;
+    }
+
+    t = m_get(slirp);
+
+    /* IPv6 packet */
+    struct ip6 *rip = mtod(t, struct ip6 *);
+    rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
+    rip->ip_dst = ip->ip_src;
+    inet_ntop(AF_INET6, &rip->ip_dst, addrstr, INET6_ADDRSTRLEN);
+    DEBUG_ARG("target = %s", addrstr);
+
+    rip->ip_nh = IPPROTO_ICMPV6;
+    const int error_data_len = min(m->m_len,
+            IF_MTU - (sizeof(struct ip6) + ICMP6_ERROR_MINLEN));
+    rip->ip_pl = htons(ICMP6_ERROR_MINLEN + error_data_len);
+    t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
+
+    /* ICMPv6 packet */
+    t->m_data += sizeof(struct ip6);
+    struct icmp6 *ricmp = mtod(t, struct icmp6 *);
+    ricmp->icmp6_type = type;
+    ricmp->icmp6_code = code;
+    ricmp->icmp6_cksum = 0;
+
+    switch (type) {
+    case ICMP6_UNREACH:
+    case ICMP6_TIMXCEED:
+        ricmp->icmp6_err.unused = 0;
+        break;
+    case ICMP6_TOOBIG:
+        ricmp->icmp6_err.mtu = htonl(IF_MTU);
+        break;
+    case ICMP6_PARAMPROB:
+        /* TODO: Handle this case */
+        break;
+    default:
+        g_assert_not_reached();
+        break;
+    }
+    t->m_data += ICMP6_ERROR_MINLEN;
+    memcpy(t->m_data, m->m_data, error_data_len);
+
+    /* Checksum */
+    t->m_data -= ICMP6_ERROR_MINLEN;
+    t->m_data -= sizeof(struct ip6);
+    ricmp->icmp6_cksum = ip6_cksum(t);
+
+    ip6_output(NULL, t, 0);
+}
+
 /*
  * Send NDP Router Advertisement
  */
diff --git a/slirp/ip6_icmp.h b/slirp/ip6_icmp.h
index b2c40d6..9460bf8 100644
--- a/slirp/ip6_icmp.h
+++ b/slirp/ip6_icmp.h
@@ -19,6 +19,12 @@  struct icmp6_echo { /* Echo Messages */
     uint16_t seq_num;
 };
 
+union icmp6_error_body {
+    uint32_t unused;
+    uint32_t pointer;
+    uint32_t mtu;
+};
+
 /*
  * NDP Messages
  */
@@ -82,6 +88,7 @@  struct icmp6 {
     uint8_t     icmp6_code;         /* type sub code */
     uint16_t    icmp6_cksum;        /* ones complement cksum of struct */
     union {
+        union icmp6_error_body error_body;
         struct icmp6_echo echo;
         struct ndp_rs ndp_rs;
         struct ndp_ra ndp_ra;
@@ -89,6 +96,7 @@  struct icmp6 {
         struct ndp_na ndp_na;
         struct ndp_redirect ndp_redirect;
     } icmp6_body;
+#define icmp6_err icmp6_body.error_body
 #define icmp6_echo icmp6_body.echo
 #define icmp6_nrs icmp6_body.ndp_rs
 #define icmp6_nra icmp6_body.ndp_ra
@@ -98,6 +106,7 @@  struct icmp6 {
 } QEMU_PACKED;
 
 #define ICMP6_MINLEN    4
+#define ICMP6_ERROR_MINLEN  8
 #define ICMP6_ECHO_MINLEN   8
 #define ICMP6_NDP_RS_MINLEN 8
 #define ICMP6_NDP_RA_MINLEN 16
@@ -197,6 +206,7 @@  struct ndpopt {
 void icmp6_init(Slirp *slirp);
 void icmp6_cleanup(Slirp *slirp);
 void icmp6_input(struct mbuf *);
+void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code);
 void ndp_send_ra(Slirp *slirp);
 void ndp_send_ns(Slirp *slirp, struct in6_addr addr);
 
diff --git a/slirp/ip6_input.c b/slirp/ip6_input.c
index df249f1..b6a438d 100644
--- a/slirp/ip6_input.c
+++ b/slirp/ip6_input.c
@@ -39,9 +39,14 @@  void ip6_input(struct mbuf *m)
         goto bad;
     }
 
+    if (ntohs(ip6->ip_pl) > IF_MTU) {
+        icmp6_send_error(m, ICMP6_TOOBIG, 0);
+        goto bad;
+    }
+
     /* check ip_ttl for a correct ICMP reply */
     if (ip6->ip_hl == 0) {
-        /*icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");*/
+        icmp6_send_error(m, ICMP6_TIMXCEED, ICMP6_TIMXCEED_INTRANS);
         goto bad;
     }
 
@@ -49,14 +54,12 @@  void ip6_input(struct mbuf *m)
      * Switch out to protocol's input routine.
      */
     switch (ip6->ip_nh) {
-#if 0
     case IPPROTO_TCP:
-        tcp_input(m, hlen, (struct socket *)NULL);
+        icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
         break;
     case IPPROTO_UDP:
-        udp_input(m, hlen);
+        icmp6_send_error(m, ICMP6_UNREACH, ICMP6_UNREACH_NO_ROUTE);
         break;
-#endif
     case IPPROTO_ICMPV6:
         icmp6_input(m);
         break;
diff --git a/slirp/ip_icmp.c b/slirp/ip_icmp.c
index ace3982..590dada 100644
--- a/slirp/ip_icmp.c
+++ b/slirp/ip_icmp.c
@@ -38,7 +38,7 @@ 
 /* Be nice and tell them it's just a pseudo-ping packet */
 static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
 
-/* list of actions for icmp_error() on RX of an icmp message */
+/* list of actions for icmp_send_error() on RX of an icmp message */
 static const int icmp_flush[19] = {
 /*  ECHO REPLY (0)  */   0,
 		         1,
@@ -101,7 +101,7 @@  static int icmp_send(struct socket *so, struct mbuf *m, int hlen)
                (struct sockaddr *)&addr, sizeof(addr)) == -1) {
         DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n",
                     errno, strerror(errno)));
-        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
+        icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
         icmp_detach(so);
     }
 
@@ -189,7 +189,7 @@  icmp_input(struct mbuf *m, int hlen)
 		(struct sockaddr *)&addr, sizeof(addr)) == -1) {
 	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
 		    errno,strerror(errno)));
-	icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
+	icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
 	udp_detach(so);
       }
     } /* if ip->ip_dst.s_addr == alias_addr.s_addr */
@@ -235,7 +235,7 @@  end_error:
 
 #define ICMP_MAXDATALEN (IP_MSS-28)
 void
-icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
+icmp_send_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
            const char *message)
 {
   unsigned hlen, shlen, s_ip_len;
@@ -243,7 +243,7 @@  icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
   register struct icmp *icp;
   register struct mbuf *m;
 
-  DEBUG_CALL("icmp_error");
+  DEBUG_CALL("icmp_send_error");
   DEBUG_ARG("msrc = %p", msrc);
   DEBUG_ARG("msrc_len = %d", msrc->m_len);
 
@@ -433,7 +433,7 @@  void icmp_receive(struct socket *so)
         }
         DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n", errno,
                     strerror(errno)));
-        icmp_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
+        icmp_send_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
     } else {
         icmp_reflect(so->so_m);
         so->so_m = NULL; /* Don't m_free() it again! */
diff --git a/slirp/ip_icmp.h b/slirp/ip_icmp.h
index be4426b..846761d 100644
--- a/slirp/ip_icmp.h
+++ b/slirp/ip_icmp.h
@@ -156,8 +156,8 @@  struct icmp {
 void icmp_init(Slirp *slirp);
 void icmp_cleanup(Slirp *slirp);
 void icmp_input(struct mbuf *, int);
-void icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
-                const char *message);
+void icmp_send_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
+                     const char *message);
 void icmp_reflect(struct mbuf *);
 void icmp_receive(struct socket *so);
 void icmp_detach(struct socket *so);
diff --git a/slirp/ip_input.c b/slirp/ip_input.c
index e4855ae..16fb2cb 100644
--- a/slirp/ip_input.c
+++ b/slirp/ip_input.c
@@ -132,9 +132,9 @@  ip_input(struct mbuf *m)
 	   m_adj(m, ip->ip_len - m->m_len);
 
 	/* check ip_ttl for a correct ICMP reply */
-	if(ip->ip_ttl==0) {
-	  icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
-	  goto bad;
+	if (ip->ip_ttl == 0) {
+	    icmp_send_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, "ttl");
+	    goto bad;
 	}
 
 	/*
@@ -637,7 +637,7 @@  typedef uint32_t n_time;
 	}
 	return (0);
 bad:
- 	icmp_error(m, type, code, 0, 0);
+	icmp_send_error(m, type, code, 0, 0);
 
 	return (1);
 }
diff --git a/slirp/socket.c b/slirp/socket.c
index 2b5453e..32b1ba3 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -463,7 +463,7 @@  sorecvfrom(struct socket *so)
 
 	    DEBUG_MISC((dfd," udp icmp rx errno = %d-%s\n",
 			errno,strerror(errno)));
-	    icmp_error(so->so_m, ICMP_UNREACH,code, 0,strerror(errno));
+	    icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
 	  } else {
 	    icmp_reflect(so->so_m);
             so->so_m = NULL; /* Don't m_free() it again! */
@@ -511,7 +511,7 @@  sorecvfrom(struct socket *so)
 	    else if(errno == ENETUNREACH) code=ICMP_UNREACH_NET;
 
 	    DEBUG_MISC((dfd," rx error, tx icmp ICMP_UNREACH:%i\n", code));
-	    icmp_error(so->so_m, ICMP_UNREACH,code, 0,strerror(errno));
+	    icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
 	    m_free(m);
 	  } else {
 	  /*
diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index 2027a75..5f845da 100644
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -608,7 +608,7 @@  findso:
 	      m->m_data -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
 	      m->m_len  += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
 	      *ip=save_ip;
-	      icmp_error(m, ICMP_UNREACH,code, 0,strerror(errno));
+	      icmp_send_error(m, ICMP_UNREACH, code, 0, strerror(errno));
 	    }
             tcp_close(tp);
 	    m_free(m);
diff --git a/slirp/udp.c b/slirp/udp.c
index 6b39cab..be012fb 100644
--- a/slirp/udp.c
+++ b/slirp/udp.c
@@ -209,7 +209,8 @@  udp_input(register struct mbuf *m, int iphlen)
 	  m->m_data -= iphlen;
 	  *ip=save_ip;
 	  DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
-	  icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
+	  icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0,
+	                  strerror(errno));
 	  goto bad;
 	}