From: Roy Marples <roy@marples.name>
Date: Sun, 10 May 2020 11:19:59 +0000 (+0100)
Subject: privsep: Add function for indirect ioctl
X-Git-Tag: v9.1.0~82
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1608a3170735cc697625b2d472286ba95fc88a91;p=thirdparty%2Fdhcpcd.git

privsep: Add function for indirect ioctl
---

diff --git a/src/privsep-bsd.c b/src/privsep-bsd.c
index b64040d6..1a105b63 100644
--- a/src/privsep-bsd.c
+++ b/src/privsep-bsd.c
@@ -29,6 +29,7 @@
 #include <sys/ioctl.h>
 
 #include <errno.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "dhcpcd.h"
@@ -41,12 +42,30 @@ ps_root_doioctldom(int domain, unsigned long req, void *data, size_t len)
 	int s, err;
 
 	s = socket(domain, SOCK_DGRAM, 0);
-	if (s != -1)
-		err = ioctl(s, req, data, len);
-	else
-		err = -1;
-	if (s != -1)
-		close(s);
+	if (s == -1)
+		return -1;
+	err = ioctl(s, req, data, len);
+	close(s);
+	return err;
+}
+
+static ssize_t
+ps_root_doindirectioctl(unsigned long req, void *data, size_t len)
+{
+	char *p = data;
+	struct ifreq ifr = { .ifr_flags = 0 };
+	ssize_t err;
+
+	if (len < IFNAMSIZ) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	strlcpy(ifr.ifr_name, p, IFNAMSIZ);
+	ifr.ifr_data = p + IFNAMSIZ;
+	err = ps_root_doioctldom(PF_INET, req, &ifr, sizeof(ifr));
+	if (err != -1)
+		memmove(data, ifr.ifr_data, len - IFNAMSIZ);
 	return err;
 }
 
@@ -78,6 +97,8 @@ ps_root_os(struct ps_msghdr *psm, struct msghdr *msg)
 		return ps_root_doioctldom(PF_LINK, psm->ps_flags, data, len);
 	case PS_IOCTL6:
 		return ps_root_doioctldom(PF_INET6, psm->ps_flags, data, len);
+	case PS_IOCTLINDIRECT:
+		return ps_root_doindirectioctl(psm->ps_flags, data, len);
 	case PS_ROUTE:
 		return ps_root_doroute(data, len);
 	default:
@@ -113,6 +134,20 @@ ps_root_ioctl6(struct dhcpcd_ctx *ctx, unsigned long request,
 	return ps_root_ioctldom(ctx, PS_IOCTL6, request, data, len);
 }
 
+ssize_t
+ps_root_indirectioctl(struct dhcpcd_ctx *ctx, unsigned long request,
+    const char *ifname, void *data, size_t len)
+{
+	char buf[PS_BUFLEN];
+
+	strlcpy(buf, ifname, IFNAMSIZ);
+	memcpy(buf + IFNAMSIZ, data, len);
+	if (ps_sendcmd(ctx, ctx->ps_root_fd, PS_IOCTLINDIRECT,
+	    request, buf, IFNAMSIZ + len) == -1)
+		return -1;
+	return ps_root_readerror(ctx, data, len);
+}
+
 ssize_t
 ps_root_route(struct dhcpcd_ctx *ctx, void *data, size_t len)
 {
diff --git a/src/privsep-root.h b/src/privsep-root.h
index 46608792..27a481a6 100644
--- a/src/privsep-root.h
+++ b/src/privsep-root.h
@@ -44,6 +44,8 @@ ssize_t ps_root_os(struct ps_msghdr *, struct msghdr *);
 ssize_t ps_root_route(struct dhcpcd_ctx *, void *, size_t);
 ssize_t ps_root_ioctllink(struct dhcpcd_ctx *, unsigned long, void *, size_t);
 ssize_t ps_root_ioctl6(struct dhcpcd_ctx *, unsigned long, void *, size_t);
+ssize_t ps_root_indirectioctl(struct dhcpcd_ctx *, unsigned long, const char *,
+    void *, size_t);
 #endif
 #ifdef __linux__
 ssize_t ps_root_sendnetlink(struct dhcpcd_ctx *, int, struct msghdr *);
diff --git a/src/privsep.h b/src/privsep.h
index cb16ac1f..9d156e9e 100644
--- a/src/privsep.h
+++ b/src/privsep.h
@@ -52,9 +52,10 @@
 /* BSD Commands */
 #define	PS_IOCTLLINK		0x15
 #define	PS_IOCTL6		0x16
+#define	PS_IOCTLINDIRECT	0x17
 
 /* Linux commands */
-#define	PS_WRITEPATHUINT	0x17
+#define	PS_WRITEPATHUINT	0x18
 
 #define	PS_DELETE		0x20
 #define	PS_START		0x40