iproute_lwtunnel: csum_mode value checking was ineffective

ila_csum_name2mode() returning -1 on error but being declared as
returning __u8 doesn't make much sense. Change the code to correctly
detect this issue. Checking for __u8 overruns shouldn't be necessary
though since ila_csum_name2mode() return values are well-defined.

Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/ip/iproute_lwtunnel.c b/ip/iproute_lwtunnel.c
index e8cd505abab2b6f2b6436da555f3903ee6d9eb09..1a3dc4d4c0ed96003afccb91d56986b02cb2c601 100644 (file)
--- a/ip/iproute_lwtunnel.c
+++ b/ip/iproute_lwtunnel.c
@@ -171,7 +171,7 @@ static char *ila_csum_mode2name(__u8 csum_mode)
        }
 }
 
-static __u8 ila_csum_name2mode(char *name)
+static int ila_csum_name2mode(char *name)
 {
        if (strcmp(name, "adj-transport") == 0)
                return ILA_CSUM_ADJUST_TRANSPORT;
@@ -517,7 +517,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
 
        while (argc > 0) {
                if (strcmp(*argv, "csum-mode") == 0) {
-                       __u8 csum_mode;
+                       int csum_mode;
 
                        NEXT_ARG();
 
@@ -526,7 +526,8 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
                                invarg("\"csum-mode\" value is invalid\n",
                                       *argv);
 
-                       rta_addattr8(rta, 1024, ILA_ATTR_CSUM_MODE, csum_mode);
+                       rta_addattr8(rta, 1024, ILA_ATTR_CSUM_MODE,
+                                    (__u8)csum_mode);
 
                        argc--; argv++;
                } else {