Avoid embedding struct mbuf in other structures

struct mbuf uses a C99 open char array to allow inlining data. Inlining
this in another structure is however a GNU extension. The inlines used
so far in struct Slirp were actually only needed as head of struct
mbuf lists. This replaces these inline with mere struct quehead,
and use casts as appropriate.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 14 insertions, 13 deletions

diff --git a/slirp/if.c b/slirp/if.c
index 2e21f438e8..9b02180db0 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -28,9 +28,9 @@ ifs_remque(struct mbuf *ifm)
 void
 if_init(Slirp *slirp)
 {
-    slirp->if_fastq.ifq_next = slirp->if_fastq.ifq_prev = &slirp->if_fastq;
-    slirp->if_batchq.ifq_next = slirp->if_batchq.ifq_prev = &slirp->if_batchq;
-    slirp->next_m = &slirp->if_batchq;
+    slirp->if_fastq.qh_link = slirp->if_fastq.qh_rlink = &slirp->if_fastq;
+    slirp->if_batchq.qh_link = slirp->if_batchq.qh_rlink = &slirp->if_batchq;
+    slirp->next_m = (struct mbuf *) &slirp->if_batchq;
 }
 
 /*
@@ -74,7 +74,8 @@ if_output(struct socket *so, struct mbuf *ifm)
 	 * We mustn't put this packet back on the fastq (or we'll send it out of order)
 	 * XXX add cache here?
 	 */
-	for (ifq = slirp->if_batchq.ifq_prev; ifq != &slirp->if_batchq;
+	for (ifq = (struct mbuf *) slirp->if_batchq.qh_rlink;
+	     (struct quehead *) ifq != &slirp->if_batchq;
 	     ifq = ifq->ifq_prev) {
 		if (so == ifq->ifq_so) {
 			/* A match! */
@@ -86,7 +87,7 @@ if_output(struct socket *so, struct mbuf *ifm)
 
 	/* No match, check which queue to put it on */
 	if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
-		ifq = slirp->if_fastq.ifq_prev;
+		ifq = (struct mbuf *) slirp->if_fastq.qh_rlink;
 		on_fastq = 1;
 		/*
 		 * Check if this packet is a part of the last
@@ -98,9 +99,9 @@ if_output(struct socket *so, struct mbuf *ifm)
 			goto diddit;
 		}
         } else {
-		ifq = slirp->if_batchq.ifq_prev;
+		ifq = (struct mbuf *) slirp->if_batchq.qh_rlink;
                 /* Set next_m if the queue was empty so far */
-                if (slirp->next_m == &slirp->if_batchq) {
+                if ((struct quehead *) slirp->next_m == &slirp->if_batchq) {
                     slirp->next_m = ifm;
                 }
         }
@@ -166,10 +167,10 @@ void if_start(Slirp *slirp)
     }
     slirp->if_start_busy = true;
 
-    if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
-        ifm_next = slirp->if_fastq.ifq_next;
+    if (slirp->if_fastq.qh_link != &slirp->if_fastq) {
+        ifm_next = (struct mbuf *) slirp->if_fastq.qh_link;
         next_from_batchq = false;
-    } else if (slirp->next_m != &slirp->if_batchq) {
+    } else if ((struct quehead *) slirp->next_m != &slirp->if_batchq) {
         /* Nothing on fastq, pick up from batchq via next_m */
         ifm_next = slirp->next_m;
         next_from_batchq = true;
@@ -182,12 +183,12 @@ void if_start(Slirp *slirp)
         from_batchq = next_from_batchq;
 
         ifm_next = ifm->ifq_next;
-        if (ifm_next == &slirp->if_fastq) {
+        if ((struct quehead *) ifm_next == &slirp->if_fastq) {
             /* No more packets in fastq, switch to batchq */
             ifm_next = slirp->next_m;
             next_from_batchq = true;
         }
-        if (ifm_next == &slirp->if_batchq) {
+        if ((struct quehead *) ifm_next == &slirp->if_batchq) {
             /* end of batchq */
             ifm_next = NULL;
         }
@@ -218,7 +219,7 @@ void if_start(Slirp *slirp)
                 /* Next packet in fastq is from the same session */
                 ifm_next = next;
                 next_from_batchq = false;
-            } else if (slirp->next_m == &slirp->if_batchq) {
+            } else if ((struct quehead *) slirp->next_m == &slirp->if_batchq) {
                 /* Set next_m and ifm_next if the session packet is now the
                  * only one on batchq */
                 slirp->next_m = ifm_next = next;