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

[Nicholas Ngai <nicholas@ngai.me>]

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 <nicholas@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;