Commit 2ec80ad928 for qemu.org

commit 2ec80ad92840df9750e9ad5beed494cb0b202ba9
Author: Michael Tokarev <mjt@tls.msk.ru>
Date:   Tue Mar 17 11:27:18 2026 +0300

    net/slirp: allow hostfwd socket paths with dashes

    The format of hostfwd parameter is:
      hostfwd=hostpart-guestaddr:guestport
    so a minus sign can not be part of the hostpart.
    If hostpart specifies a unix socket path, this becomes problematic.

    To solve this, look for the LAST minus/dash char in the string,
    not first.

    Unfortunately, [-guestaddr] is optional (defaults to 10.0.0.15),
    so we still can't parse the thing in an uniform way.

    Extend get_str_sep() to accept negative separator to indicate searching
    from the end of buffer, to find the last occurence.  Update slirp_hostfwd
    to search for the last separator when parsing unix domain socket path.

    Inspired-by: Christopher Palmer-Richez <crichez@pm.me>
    Resolves: https://gitlab.com/qemu-project/qemu/-/issues/347
    Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/net/slirp.c b/net/slirp.c
index a00e0a9651..9e9941fe73 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -54,7 +54,8 @@ static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
     const char *p, *p1;
     int len;
     p = *pp;
-    p1 = strchr(p, sep);
+    /* negative sep means to search -sep from the end of buf */
+    p1 = sep >= 0 ? strchr(p, sep) : strrchr(p, -sep);
     if (!p1)
         return -1;
     len = p1 - p;
@@ -848,7 +849,7 @@ static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)

 #if !defined(WIN32) && SLIRP_CHECK_VERSION(4, 7, 0)
     if (is_unix) {
-        if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
+        if (get_str_sep(buf, sizeof(buf), &p, 0 - '-') < 0) {
             fail_reason = "Missing - separator";
             goto fail_syntax;
         }