From b918c07567cfe73ca8598bc8e94a743c3991f933 Mon Sep 17 00:00:00 2001
From: Tomas Paukrt <44699103+tpaukrt@users.noreply.github.com>
Date: Tue, 10 Sep 2024 12:13:59 +0200
Subject: [PATCH] pppd: Add ip-pre-up-script option (#510)

This option allows a user to specify the path to the script
usually located at /etc/ppp/ip-pre-up, similarly to the
existing ip-up-script and ip-down-script options.

Signed-off-by: Tomas Paukrt <tomaspaukrt@email.cz>
---
 pppd/ipcp.c         | 4 ++--
 pppd/main.c         | 1 +
 pppd/options.c      | 4 ++++
 pppd/pppd-private.h | 1 +
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/pppd/ipcp.c b/pppd/ipcp.c
index 850e8cc89..06dfd8940 100644
--- a/pppd/ipcp.c
+++ b/pppd/ipcp.c
@@ -1766,7 +1766,7 @@ ip_demand_conf(int u)
     }
     if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
 	return 0;
-    ipcp_script(PPP_PATH_IPPREUP, 1);
+    ipcp_script(path_ippreup, 1);
     if (!sifup(u))
 	return 0;
     if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
@@ -1932,7 +1932,7 @@ ipcp_up(fsm *f)
 	ifindex = if_nametoindex(ifname);
 
 	/* run the pre-up script, if any, and wait for it to finish */
-	ipcp_script(PPP_PATH_IPPREUP, 1);
+	ipcp_script(path_ippreup, 1);
 
 	/* check if preup script renamed the interface */
 	if (!if_indextoname(ifindex, ifname)) {
diff --git a/pppd/main.c b/pppd/main.c
index b68917ff6..d8d62fe5f 100644
--- a/pppd/main.c
+++ b/pppd/main.c
@@ -365,6 +365,7 @@ main(int argc, char *argv[])
 
     strlcpy(path_ipup, PPP_PATH_IPUP, MAXPATHLEN);
     strlcpy(path_ipdown, PPP_PATH_IPDOWN, MAXPATHLEN);
+    strlcpy(path_ippreup, PPP_PATH_IPPREUP, MAXPATHLEN);
 
 #ifdef PPP_WITH_IPV6CP
     strlcpy(path_ipv6up, PPP_PATH_IPV6UP, MAXPATHLEN);
diff --git a/pppd/options.c b/pppd/options.c
index 227e615c9..2cdfaf271 100644
--- a/pppd/options.c
+++ b/pppd/options.c
@@ -123,6 +123,7 @@ int	connect_delay = 1000;	/* wait this many ms after connect script */
 int	req_unit = -1;		/* requested interface unit */
 char	path_ipup[MAXPATHLEN];	/* pathname of ip-up script */
 char	path_ipdown[MAXPATHLEN];/* pathname of ip-down script */
+char	path_ippreup[MAXPATHLEN]; /* pathname of ip-pre-up script */
 char	req_ifname[IFNAMSIZ];	/* requested interface name */
 bool	multilink = 0;		/* Enable multilink operation */
 char	*bundle_name = NULL;	/* bundle name for multilink */
@@ -337,6 +338,9 @@ struct option general_options[] = {
     { "ip-down-script", o_string, path_ipdown,
       "Set pathname of ip-down script",
       OPT_PRIV|OPT_STATIC, NULL, MAXPATHLEN },
+    { "ip-pre-up-script", o_string, path_ippreup,
+      "Set pathname of ip-pre-up script",
+      OPT_PRIV|OPT_STATIC, NULL, MAXPATHLEN },
 
 #ifdef PPP_WITH_IPV6CP
     { "ipv6-up-script", o_string, path_ipv6up,
diff --git a/pppd/pppd-private.h b/pppd/pppd-private.h
index 46ce0c8bd..a38f58a09 100644
--- a/pppd/pppd-private.h
+++ b/pppd/pppd-private.h
@@ -194,6 +194,7 @@ extern int	max_data_rate;	/* max bytes/sec through charshunt */
 extern int	req_unit;	/* interface unit number to use */
 extern char	path_ipup[]; 	/* pathname of ip-up script */
 extern char	path_ipdown[];	/* pathname of ip-down script */
+extern char	path_ippreup[];	/* pathname of ip-pre-up script */
 extern char	req_ifname[]; /* interface name to use (IFNAMSIZ) */
 extern bool	multilink;	/* enable multilink operation (options.c) */
 extern bool	noendpoint;	/* don't send or accept endpt. discrim. */