libslirp 4.7 introduces a CFI-friendly version of the .timer_new callback.
The new callback replaces the function pointer with an enum; invoking the
callback is done with a new function slirp_handle_timer.

Support the new API so that CFI can be made compatible with using a system
libslirp.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 net/slirp.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/net/slirp.c b/net/slirp.c
index b3a92d6e38..57af42299d 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -184,10 +184,43 @@ static int64_t net_slirp_clock_get_ns(void *opaque)
     return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 }
 
+typedef struct SlirpTimer SlirpTimer;
 struct SlirpTimer {
     QEMUTimer timer;
+#if SLIRP_CHECK_VERSION(4,7,0)
+    Slirp *slirp;
+    SlirpTimerId id;
+    void *cb_opaque;
+#endif
+};
+
+#if SLIRP_CHECK_VERSION(4,7,0)
+static void net_slirp_init_completed(Slirp *slirp, void *opaque)
+{
+    SlirpState *s = opaque;
+    s->slirp = slirp;
 }
 
+static void net_slirp_timer_cb(void *opaque)
+{
+    SlirpTimer *t = opaque;
+    slirp_handle_timer(t->slirp, t->id, t->cb_opaque);
+}
+
+static void *net_slirp_timer_new_opaque(SlirpTimerId id,
+                                        void *cb_opaque, void *opaque)
+{
+    SlirpState *s = opaque;
+    SlirpTimer *t = g_new(SlirpTimer, 1);
+    t->slirp = s->slirp;
+    t->id = id;
+    t->cb_opaque = cb_opaque;
+    timer_init_full(&t->timer, NULL, QEMU_CLOCK_VIRTUAL,
+                    SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
+                    net_slirp_timer_cb, t);
+    return t;
+}
+#else
 static void *net_slirp_timer_new(SlirpTimerCb cb,
                                  void *cb_opaque, void *opaque)
 {
@@ -197,6 +230,7 @@ static void *net_slirp_timer_new(SlirpTimerCb cb,
                     cb, cb_opaque);
     return t;
 }
+#endif
 
 static void net_slirp_timer_free(void *timer, void *opaque)
 {
@@ -231,7 +265,12 @@ static const SlirpCb slirp_cb = {
     .send_packet = net_slirp_send_packet,
     .guest_error = net_slirp_guest_error,
     .clock_get_ns = net_slirp_clock_get_ns,
+#if SLIRP_CHECK_VERSION(4,7,0)
+    .init_completed = net_slirp_init_completed,
+    .timer_new_opaque = net_slirp_timer_new_opaque,
+#else
     .timer_new = net_slirp_timer_new,
+#endif
     .timer_free = net_slirp_timer_free,
     .timer_mod = net_slirp_timer_mod,
     .register_poll_fd = net_slirp_register_poll_fd,
@@ -578,7 +617,7 @@ static int net_slirp_init(NetClientState *peer, const char *model,
 
     s = DO_UPCAST(SlirpState, nc, nc);
 
-    cfg.version = 3;
+    cfg.version = SLIRP_CHECK_VERSION(4,7,0) ? 4 : 3;
     cfg.restricted = restricted;
     cfg.in_enabled = ipv4;
     cfg.vnetwork = net;
-- 
2.35.1

Paolo Bonzini, le mar. 12 avril 2022 14:13:36 +0200, a ecrit:
> libslirp 4.7 introduces a CFI-friendly version of the .timer_new callback.
> The new callback replaces the function pointer with an enum; invoking the
> callback is done with a new function slirp_handle_timer.
> 
> Support the new API so that CFI can be made compatible with using a system
> libslirp.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
>  net/slirp.c | 41 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 40 insertions(+), 1 deletion(-)
> 
> diff --git a/net/slirp.c b/net/slirp.c
> index b3a92d6e38..57af42299d 100644
> --- a/net/slirp.c
> +++ b/net/slirp.c
> @@ -184,10 +184,43 @@ static int64_t net_slirp_clock_get_ns(void *opaque)
>      return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
>  }
>  
> +typedef struct SlirpTimer SlirpTimer;
>  struct SlirpTimer {
>      QEMUTimer timer;
> +#if SLIRP_CHECK_VERSION(4,7,0)
> +    Slirp *slirp;
> +    SlirpTimerId id;
> +    void *cb_opaque;
> +#endif
> +};
> +
> +#if SLIRP_CHECK_VERSION(4,7,0)
> +static void net_slirp_init_completed(Slirp *slirp, void *opaque)
> +{
> +    SlirpState *s = opaque;
> +    s->slirp = slirp;
>  }
>  
> +static void net_slirp_timer_cb(void *opaque)
> +{
> +    SlirpTimer *t = opaque;
> +    slirp_handle_timer(t->slirp, t->id, t->cb_opaque);
> +}
> +
> +static void *net_slirp_timer_new_opaque(SlirpTimerId id,
> +                                        void *cb_opaque, void *opaque)
> +{
> +    SlirpState *s = opaque;
> +    SlirpTimer *t = g_new(SlirpTimer, 1);
> +    t->slirp = s->slirp;
> +    t->id = id;
> +    t->cb_opaque = cb_opaque;
> +    timer_init_full(&t->timer, NULL, QEMU_CLOCK_VIRTUAL,
> +                    SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
> +                    net_slirp_timer_cb, t);
> +    return t;
> +}
> +#else
>  static void *net_slirp_timer_new(SlirpTimerCb cb,
>                                   void *cb_opaque, void *opaque)
>  {
> @@ -197,6 +230,7 @@ static void *net_slirp_timer_new(SlirpTimerCb cb,
>                      cb, cb_opaque);
>      return t;
>  }
> +#endif
>  
>  static void net_slirp_timer_free(void *timer, void *opaque)
>  {
> @@ -231,7 +265,12 @@ static const SlirpCb slirp_cb = {
>      .send_packet = net_slirp_send_packet,
>      .guest_error = net_slirp_guest_error,
>      .clock_get_ns = net_slirp_clock_get_ns,
> +#if SLIRP_CHECK_VERSION(4,7,0)
> +    .init_completed = net_slirp_init_completed,
> +    .timer_new_opaque = net_slirp_timer_new_opaque,
> +#else
>      .timer_new = net_slirp_timer_new,
> +#endif
>      .timer_free = net_slirp_timer_free,
>      .timer_mod = net_slirp_timer_mod,
>      .register_poll_fd = net_slirp_register_poll_fd,
> @@ -578,7 +617,7 @@ static int net_slirp_init(NetClientState *peer, const char *model,
>  
>      s = DO_UPCAST(SlirpState, nc, nc);
>  
> -    cfg.version = 3;
> +    cfg.version = SLIRP_CHECK_VERSION(4,7,0) ? 4 : 3;
>      cfg.restricted = restricted;
>      cfg.in_enabled = ipv4;
>      cfg.vnetwork = net;
> -- 
> 2.35.1
> 
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.