From: Daniil Tatianin <d-tatianin@yandex-team.ru>
Date: Thu, 27 Feb 2025 08:46:25 +0000 (+0300)
Subject: platform: introduce a way to hook new session start
X-Git-Tag: V_10_0_P1~25
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fdc4853c5b1567934d43ab13282f03033cc21325;p=thirdparty%2Fopenssh-portable.git

platform: introduce a way to hook new session start

Previously this was possible via post_fork_child, but ever since sshd
was split into multiple binaries, this is now no longer possible becase
of execv.
---

diff --git a/Makefile.in b/Makefile.in
index 974be207a..4617cebcd 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -140,7 +140,7 @@ SSHD_SESSION_OBJS=sshd-session.o auth-rhosts.o auth-passwd.o \
 	auth2-gss.o gss-serv.o gss-serv-krb5.o \
 	loginrec.o auth-pam.o auth-shadow.o auth-sia.o \
 	sftp-server.o sftp-common.o \
-	uidswap.o $(SKOBJS)
+	uidswap.o platform-listen.o $(SKOBJS)
 
 SSHD_AUTH_OBJS=sshd-auth.o \
 	auth2-methods.o \
diff --git a/platform-listen.c b/platform-listen.c
index 42c4040f0..4da2855ee 100644
--- a/platform-listen.c
+++ b/platform-listen.c
@@ -82,3 +82,6 @@ platform_post_fork_child(void)
 #endif
 }
 
+void platform_pre_session_start(void)
+{
+}
diff --git a/platform.h b/platform.h
index 5dec23276..08cbd225d 100644
--- a/platform.h
+++ b/platform.h
@@ -24,6 +24,7 @@ void platform_pre_restart(void);
 void platform_post_listen(void);
 void platform_post_fork_parent(pid_t child_pid);
 void platform_post_fork_child(void);
+void platform_pre_session_start(void);
 int  platform_privileged_uidswap(void);
 void platform_setusercontext(struct passwd *);
 void platform_setusercontext_post_groups(struct passwd *);
diff --git a/sshd-session.c b/sshd-session.c
index 1e2cee10f..c64eb29fc 100644
--- a/sshd-session.c
+++ b/sshd-session.c
@@ -999,6 +999,8 @@ main(int ac, char **av)
 
 	closefrom(REEXEC_MIN_FREE_FD);
 
+	platform_pre_session_start();
+
 	/* Reserve fds we'll need later for reexec things */
 	if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1)
 		fatal("open %s: %s", _PATH_DEVNULL, strerror(errno));