From ef76dff225a00008fe0edd1f528c9096f1a91179 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 6 May 2016 20:58:32 +0200 Subject: util-lib: add new ifname_valid() call that validates interface names Make use of this in nspawn at a couple of places. A later commit should port more code over to this, including networkd. --- src/basic/socket-util.c | 38 ++++++++++++++++++++++++++++++++++++++ src/basic/socket-util.h | 2 ++ src/nspawn/nspawn-network.c | 6 ++++-- src/nspawn/nspawn.c | 24 ++++++++++++++++++++++++ src/test/test-socket-util.c | 25 +++++++++++++++++++++++++ 5 files changed, 93 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c index c634f1d564..c8769a54f4 100644 --- a/src/basic/socket-util.c +++ b/src/basic/socket-util.c @@ -43,7 +43,9 @@ #include "socket-util.h" #include "string-table.h" #include "string-util.h" +#include "strv.h" #include "user-util.h" +#include "utf8.h" #include "util.h" int socket_address_parse(SocketAddress *a, const char *s) { @@ -795,6 +797,42 @@ static const char* const ip_tos_table[] = { DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff); +bool ifname_valid(const char *p) { + bool numeric = true; + + /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources + * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We + * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */ + + if (isempty(p)) + return false; + + if (strlen(p) >= IFNAMSIZ) + return false; + + if (STR_IN_SET(p, ".", "..")) + return false; + + while (*p) { + if ((unsigned char) *p >= 127U) + return false; + + if ((unsigned char) *p <= 32U) + return false; + + if (*p == ':' || *p == '/') + return false; + + numeric = numeric && (*p >= '0' && *p <= '9'); + p++; + } + + if (numeric) + return false; + + return true; +} + int getpeercred(int fd, struct ucred *ucred) { socklen_t n = sizeof(struct ucred); struct ucred u; diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h index 160f7c484b..e9230e4a9f 100644 --- a/src/basic/socket-util.h +++ b/src/basic/socket-util.h @@ -123,6 +123,8 @@ int fd_inc_rcvbuf(int fd, size_t n); int ip_tos_to_string_alloc(int i, char **s); int ip_tos_from_string(const char *s); +bool ifname_valid(const char *p); + int getpeercred(int fd, struct ucred *ucred); int getpeersec(int fd, char **ret); diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c index f2b7e4dd79..9938fce503 100644 --- a/src/nspawn/nspawn-network.c +++ b/src/nspawn/nspawn-network.c @@ -29,6 +29,8 @@ #include "netlink-util.h" #include "nspawn-network.h" #include "siphash24.h" +#include "socket-util.h" +#include "stat-util.h" #include "string-util.h" #include "udev-util.h" #include "util.h" @@ -515,13 +517,13 @@ int veth_extra_parse(char ***l, const char *p) { r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS); if (r < 0) return r; - if (r == 0 || isempty(a)) + if (r == 0 || !ifname_valid(a)) return -EINVAL; r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS); if (r < 0) return r; - if (r == 0 || isempty(b)) { + if (r == 0 || !ifname_valid(b)) { free(b); b = strdup(a); if (!b) diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index 3fc6cc955c..643f459851 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -467,6 +467,12 @@ static int parse_argv(int argc, char *argv[]) { break; case ARG_NETWORK_BRIDGE: + + if (!ifname_valid(optarg)) { + log_error("Bridge interface name not valid: %s", optarg); + return -EINVAL; + } + r = free_and_strdup(&arg_network_bridge, optarg); if (r < 0) return log_oom(); @@ -489,6 +495,12 @@ static int parse_argv(int argc, char *argv[]) { break; case ARG_NETWORK_INTERFACE: + + if (!ifname_valid(optarg)) { + log_error("Network interface name not valid: %s", optarg); + return -EINVAL; + } + if (strv_extend(&arg_network_interfaces, optarg) < 0) return log_oom(); @@ -497,6 +509,12 @@ static int parse_argv(int argc, char *argv[]) { break; case ARG_NETWORK_MACVLAN: + + if (!ifname_valid(optarg)) { + log_error("MACVLAN network interface name not valid: %s", optarg); + return -EINVAL; + } + if (strv_extend(&arg_network_macvlan, optarg) < 0) return log_oom(); @@ -505,6 +523,12 @@ static int parse_argv(int argc, char *argv[]) { break; case ARG_NETWORK_IPVLAN: + + if (!ifname_valid(optarg)) { + log_error("IPVLAN network interface name not valid: %s", optarg); + return -EINVAL; + } + if (strv_extend(&arg_network_ipvlan, optarg) < 0) return log_oom(); diff --git a/src/test/test-socket-util.c b/src/test/test-socket-util.c index 9e01f3afd4..b480fdaa9c 100644 --- a/src/test/test-socket-util.c +++ b/src/test/test-socket-util.c @@ -27,6 +27,29 @@ #include "string-util.h" #include "util.h" +static void test_ifname_valid(void) { + assert(ifname_valid("foo")); + assert(ifname_valid("eth0")); + + assert(!ifname_valid("0")); + assert(!ifname_valid("99")); + assert(ifname_valid("a99")); + assert(ifname_valid("99a")); + + assert(!ifname_valid(NULL)); + assert(!ifname_valid("")); + assert(!ifname_valid(" ")); + assert(!ifname_valid(" foo")); + assert(!ifname_valid("bar\n")); + assert(!ifname_valid(".")); + assert(!ifname_valid("..")); + assert(ifname_valid("foo.bar")); + assert(!ifname_valid("x:y")); + + assert(ifname_valid("xxxxxxxxxxxxxxx")); + assert(!ifname_valid("xxxxxxxxxxxxxxxx")); +} + static void test_socket_address_parse(void) { SocketAddress a; @@ -362,6 +385,8 @@ int main(int argc, char *argv[]) { log_set_max_level(LOG_DEBUG); + test_ifname_valid(); + test_socket_address_parse(); test_socket_address_parse_netlink(); test_socket_address_equal(); -- cgit v1.2.3-54-g00ecf