transmission: add seccomp filter and improve jail

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

net/transmission/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=transmission
 PKG_VERSION:=2.94
-PKG_RELEASE:=8
+PKG_RELEASE:=9
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@GITHUB/transmission/transmission-releases/master
@@ -24,6 +24,7 @@ PKG_INSTALL:=1
 PKG_BUILD_PARALLEL:=1
 
 include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/package-seccomp.mk
 
 define Package/transmission/template
   SUBMENU:=BitTorrent
@@ -150,6 +151,7 @@ define Package/transmission-daemon-openssl/install
 	$(INSTALL_CONF) files/transmission.config $(1)/etc/config/transmission
 	$(INSTALL_DIR) $(1)/etc/sysctl.d/
 	$(INSTALL_CONF) files/transmission.sysctl $(1)/etc/sysctl.d/20-transmission.conf
+	$(call InstallSeccomp,$(1),./files/transmission-daemon.json)
 endef
 Package/transmission-daemon-mbedtls/install = $(Package/transmission-daemon-openssl/install)
 

net/transmission/files/transmission-daemon.json

@@ -0,0 +1,74 @@
+{
+	"whitelist": [
+		"accept4",
+		"access",
+		"arm_fadvise64_64",
+		"bind",
+		"brk",
+		"clock_gettime",
+		"clone",
+		"close",
+		"connect",
+		"epoll_create1",
+		"epoll_ctl",
+		"epoll_pwait",
+		"exit",
+		"exit_group",
+		"fadvise64",
+		"fallocate",
+		"fcntl",
+		"fcntl64",
+		"fstat",
+		"fstat64",
+		"fsync",
+		"futex",
+		"getdents64",
+		"getpeername",
+		"getpid",
+		"getsockname",
+		"getsockopt",
+		"ioctl",
+		"listen",
+		"_llseek",
+		"lseek",
+		"madvise",
+		"membarrier",
+		"mkdir",
+		"mmap",
+		"mmap2",
+		"mprotect",
+		"munmap",
+		"nanosleep",
+		"_newselect",
+		"open",
+		"pipe",
+		"pipe2",
+		"poll",
+		"pread64",
+		"prlimit64",
+		"pwrite64",
+		"read",
+		"readlink",
+		"readv",
+		"recvfrom",
+		"rename",
+		"rmdir",
+		"rt_sigaction",
+		"rt_sigprocmask",
+		"rt_sigreturn",
+		"select",
+		"sendto",
+		"setsockopt",
+		"shutdown",
+		"sigreturn",
+		"socket",
+		"stat",
+		"stat64",
+		"umask",
+		"uname",
+		"unlink",
+		"write",
+		"writev"
+	],
+	"policy": 1
+}

net/transmission/files/transmission.init

@@ -48,7 +48,7 @@ transmission() {
 	local user
 	local group
 	local config_overwrite
-	local download_dir config_dir
+	local download_dir config_dir incomplete_dir incomplete_dir_enabled
 	local mem_percentage
 	local nice
 	local web_home
@@ -59,6 +59,8 @@ transmission() {
 	config_get user "$cfg" 'user'
 	config_get group "$cfg" 'group'
 	config_get download_dir "$cfg" 'download_dir' '/var/etc/transmission'
+	config_get incomplete_dir "$cfg" 'incomplete_dir' '/var/etc/transmission'
+	config_get incomplete_dir_enabled "$cfg" 'incomplete_dir_enabled' 0
 	config_get mem_percentage "$cfg" 'mem_percentage' '50'
 	config_get config_overwrite "$cfg" config_overwrite 1
 	config_get nice "$cfg" nice 0
@@ -71,11 +73,27 @@ transmission() {
 		USE=$((MEM * mem_percentage * 10))
 	fi
 
+	[ -d "$download_dir" ] || {
+		mkdir -p "$download_dir"
+		chmod 0755 "$download_dir"
+		[ -z "$user" ] || chown -R "$user:$group" "$download_dir"
+	}
+
+	[ "$incomplete_dir_enabled" = "0" ] || [ -d "$incomplete_dir" ] || {
+		mkdir -p "$incomplete_dir"
+		chmod 0755 "$incomplete_dir"
+		[ -z "$user" ] || chown -R "$user:$group" "$incomplete_dir"
+	}
+
 	config_file="$config_dir/settings.json"
 	[ -d "$config_dir" ] || {
 		mkdir -p "$config_dir"
 		chmod 0755 "$config_dir"
 		touch "$config_file"
+		mkdir -p "$config_dir/resume"
+		mkdir -p "$config_dir/torrents"
+		mkdir -p "$config_dir/blocklists"
+		[ -e "$config_dir/stats.json" ] || touch "$config_dir/stats.json"
 		[ -z "$user" ] || chown -R "$user:$group" "$config_dir"
 	}
 
@@ -120,6 +138,7 @@ transmission() {
 	procd_set_param nice "$nice"
 	procd_set_param stderr 1
 	procd_set_param respawn
+	procd_set_param seccomp "/etc/seccomp/transmission-daemon.json"
 
 	if [ -z "$USE" ]; then
 		procd_set_param limits core="0 0"
@@ -134,6 +153,10 @@ transmission() {
 
 	procd_add_jail transmission log
 	procd_add_jail_mount "$config_file"
+	procd_add_jail_mount_rw "$config_dir/resume"
+	procd_add_jail_mount_rw "$config_dir/torrents"
+	procd_add_jail_mount rw "$config_dir/blocklists"
+	procd_add_jail_mount_rw "$config_dir/stats.json"
 	procd_add_jail_mount_rw "$download_dir"
 	procd_close_instance
 }