Re: [PATCH] net/slirp: Use newer slirp_*_hostxfwd API

[Nicholas Ngai]

Hi,

Sorry for the duplicate email. The cc’s for the maintainers on the email 
didn’t go through the first time.

Nicholas Ngai

On 9/25/21 2:48 PM, Nicholas Ngai wrote:
libslirp provides a newer slirp_*_hostxfwd API meant for
address-agnostic forwarding instead of the is_udp parameter which is
limited to just TCP/UDP.

Signed-off-by: Nicholas Ngai <nicho...@ngai.me>
---
  net/slirp.c | 64 +++++++++++++++++++++++++++++++++++------------------
  1 file changed, 42 insertions(+), 22 deletions(-)

diff --git a/net/slirp.c b/net/slirp.c
index ad3a838e0b..49ae01a2f0 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -643,12 +643,17 @@ static SlirpState *slirp_lookup(Monitor *mon, const char 
*id)
  
  void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
  {
-    struct in_addr host_addr = { .s_addr = INADDR_ANY };
-    int host_port;
+    struct sockaddr_in host_addr = {
+        .sin_family = AF_INET,
+        .sin_addr = {
+            .s_addr = INADDR_ANY,
+        },
+    };
+    int port;
+    int flags = 0;
      char buf[256];
      const char *src_str, *p;
      SlirpState *s;
-    int is_udp = 0;
      int err;
      const char *arg1 = qdict_get_str(qdict, "arg1");
      const char *arg2 = qdict_get_try_str(qdict, "arg2");
@@ -670,9 +675,9 @@ void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
      }
  
      if (!strcmp(buf, "tcp") || buf[0] == '\0') {
-        is_udp = 0;
+        /* Do nothing; already TCP. */
      } else if (!strcmp(buf, "udp")) {
-        is_udp = 1;
+        flags |= SLIRP_HOSTFWD_UDP;
      } else {
          goto fail_syntax;
      }
@@ -680,15 +685,17 @@ void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
      if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
          goto fail_syntax;
      }
-    if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
+    if (buf[0] != '\0' && !inet_aton(buf, &host_addr.sin_addr)) {
          goto fail_syntax;
      }
  
-    if (qemu_strtoi(p, NULL, 10, &host_port)) {
+    if (qemu_strtoi(p, NULL, 10, &port)) {
          goto fail_syntax;
      }
+    host_addr.sin_port = htons(port);
  
-    err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
+    err = slirp_remove_hostxfwd(s->slirp, (struct sockaddr *) &host_addr,
+            sizeof(host_addr), flags);
  
      monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
                     err ? "not found" : "removed");
@@ -700,12 +707,22 @@ void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
  
  static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
  {
-    struct in_addr host_addr = { .s_addr = INADDR_ANY };
-    struct in_addr guest_addr = { .s_addr = 0 };
-    int host_port, guest_port;
+    struct sockaddr_in host_addr = {
+        .sin_family = AF_INET,
+        .sin_addr = {
+            .s_addr = INADDR_ANY,
+        },
+    };
+    struct sockaddr_in guest_addr = {
+        .sin_family = AF_INET,
+        .sin_addr = {
+            .s_addr = 0,
+        },
+    };
+    int flags = 0;
+    int port;
      const char *p;
      char buf[256];
-    int is_udp;
      char *end;
      const char *fail_reason = "Unknown reason";
  
@@ -715,9 +732,9 @@ static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
          goto fail_syntax;
      }
      if (!strcmp(buf, "tcp") || buf[0] == '\0') {
-        is_udp = 0;
+        /* Do nothing; already TCP. */
      } else if (!strcmp(buf, "udp")) {
-        is_udp = 1;
+        flags |= SLIRP_HOSTFWD_UDP;
      } else {
          fail_reason = "Bad protocol name";
          goto fail_syntax;
@@ -727,7 +744,7 @@ static int slirp_hostfwd(SlirpState *s, const char 
*redir_str, Error **errp)
          fail_reason = "Missing : separator";
          goto fail_syntax;
      }
-    if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
+    if (buf[0] != '\0' && !inet_aton(buf, &host_addr.sin_addr)) {
          fail_reason = "Bad host address";
          goto fail_syntax;
      }
@@ -736,29 +753,32 @@ static int slirp_hostfwd(SlirpState *s, const char 
*redir_str, Error **errp)
          fail_reason = "Bad host port separator";
          goto fail_syntax;
      }
-    host_port = strtol(buf, &end, 0);
-    if (*end != '\0' || host_port < 0 || host_port > 65535) {
+    port = strtol(buf, &end, 0);
+    if (*end != '\0' || port < 0 || port > 65535) {
          fail_reason = "Bad host port";
          goto fail_syntax;
      }
+    host_addr.sin_port = htons(port);
  
      if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
          fail_reason = "Missing guest address";
          goto fail_syntax;
      }
-    if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
+    if (buf[0] != '\0' && !inet_aton(buf, &guest_addr.sin_addr)) {
          fail_reason = "Bad guest address";
          goto fail_syntax;
      }
  
-    guest_port = strtol(p, &end, 0);
-    if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
+    port = strtol(p, &end, 0);
+    if (*end != '\0' || port < 1 || port > 65535) {
          fail_reason = "Bad guest port";
          goto fail_syntax;
      }
+    guest_addr.sin_port = htons(port);
  
-    if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
-                          guest_port) < 0) {
+    if (slirp_add_hostxfwd(s->slirp, (struct sockaddr *) &host_addr,
+                           sizeof(host_addr), (struct sockaddr *) &guest_addr,
+                           sizeof(guest_addr), flags) < 0) {
          error_setg(errp, "Could not set up host forwarding rule '%s'",
                     redir_str);
          return -1;