ip: nexthop: parse attributes into nh entry structure before printing

Factor out the nexthop attribute parsing and parse attributes into a
nexthop entry structure which is then used to print.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/ip/ipnexthop.c b/ip/ipnexthop.c
index 7094d6cbb5e65dbfb9d410ec5ed6f9269dbc6a91..0edb3c265b6f9ef88f4afff51c70719f22ea58e6 100644 (file)
--- a/ip/ipnexthop.c
+++ b/ip/ipnexthop.c
@@ -213,28 +213,29 @@ out:
        return rc;
 }
 
-static void print_nh_group(FILE *fp, const struct rtattr *grps_attr)
+static bool __valid_nh_group_attr(const struct rtattr *g_attr)
 {
-       struct nexthop_grp *nhg = RTA_DATA(grps_attr);
-       int num = RTA_PAYLOAD(grps_attr) / sizeof(*nhg);
-       int i;
+       int num = RTA_PAYLOAD(g_attr) / sizeof(struct nexthop_grp);
 
-       if (!num || num * sizeof(*nhg) != RTA_PAYLOAD(grps_attr)) {
-               fprintf(fp, "<invalid nexthop group>");
-               return;
-       }
+       return num && num * sizeof(struct nexthop_grp) == RTA_PAYLOAD(g_attr);
+}
+
+static void print_nh_group(const struct nh_entry *nhe)
+{
+       int i;
 
        open_json_array(PRINT_JSON, "group");
        print_string(PRINT_FP, NULL, "%s", "group ");
-       for (i = 0; i < num; ++i) {
+       for (i = 0; i < nhe->nh_groups_cnt; ++i) {
                open_json_object(NULL);
 
                if (i)
                        print_string(PRINT_FP, NULL, "%s", "/");
 
-               print_uint(PRINT_ANY, "id", "%u", nhg[i].id);
-               if (nhg[i].weight)
-                       print_uint(PRINT_ANY, "weight", ",%u", nhg[i].weight + 1);
+               print_uint(PRINT_ANY, "id", "%u", nhe->nh_groups[i].id);
+               if (nhe->nh_groups[i].weight)
+                       print_uint(PRINT_ANY, "weight", ",%u",
+                                  nhe->nh_groups[i].weight + 1);
 
                close_json_object();
        }
@@ -254,15 +255,13 @@ static const char *nh_group_type_name(__u16 type)
        }
 }
 
-static void print_nh_group_type(FILE *fp, const struct rtattr *grp_type_attr)
+static void print_nh_group_type(__u16 nh_grp_type)
 {
-       __u16 type = rta_getattr_u16(grp_type_attr);
-
-       if (type == NEXTHOP_GRP_TYPE_MPATH)
+       if (nh_grp_type == NEXTHOP_GRP_TYPE_MPATH)
                /* Do not print type in order not to break existing output. */
                return;
 
-       print_string(PRINT_ANY, "type", "type %s ", nh_group_type_name(type));
+       print_string(PRINT_ANY, "type", "type %s ", nh_group_type_name(nh_grp_type));
 }
 
 static void parse_nh_res_group_rta(const struct rtattr *res_grp_attr,
@@ -340,12 +339,104 @@ static void print_nh_res_bucket(FILE *fp, const struct rtattr *res_bucket_attr)
        close_json_object();
 }
 
+static void ipnh_destroy_entry(struct nh_entry *nhe)
+{
+       if (nhe->nh_encap)
+               free(nhe->nh_encap);
+       if (nhe->nh_groups)
+               free(nhe->nh_groups);
+}
+
+/* parse nhmsg into nexthop entry struct which must be destroyed by
+ * ipnh_destroy_enty when it's not needed anymore
+ */
+static int ipnh_parse_nhmsg(FILE *fp, const struct nhmsg *nhm, int len,
+                           struct nh_entry *nhe)
+{
+       struct rtattr *tb[NHA_MAX+1];
+       int err = 0;
+
+       memset(nhe, 0, sizeof(*nhe));
+       parse_rtattr_flags(tb, NHA_MAX, RTM_NHA(nhm), len, NLA_F_NESTED);
+
+       if (tb[NHA_ID])
+               nhe->nh_id = rta_getattr_u32(tb[NHA_ID]);
+
+       if (tb[NHA_OIF])
+               nhe->nh_oif = rta_getattr_u32(tb[NHA_OIF]);
+
+       if (tb[NHA_GROUP_TYPE])
+               nhe->nh_grp_type = rta_getattr_u16(tb[NHA_GROUP_TYPE]);
+
+       if (tb[NHA_GATEWAY]) {
+               if (RTA_PAYLOAD(tb[NHA_GATEWAY]) > sizeof(nhe->nh_gateway)) {
+                       fprintf(fp, "<nexthop id %u invalid gateway length %lu>\n",
+                               nhe->nh_id, RTA_PAYLOAD(tb[NHA_GATEWAY]));
+                       err = -EINVAL;
+                       goto out_err;
+               }
+               nhe->nh_gateway_len = RTA_PAYLOAD(tb[NHA_GATEWAY]);
+               memcpy(&nhe->nh_gateway, RTA_DATA(tb[NHA_GATEWAY]),
+                      RTA_PAYLOAD(tb[NHA_GATEWAY]));
+       }
+
+       if (tb[NHA_ENCAP]) {
+               nhe->nh_encap = malloc(RTA_LENGTH(RTA_PAYLOAD(tb[NHA_ENCAP])));
+               if (!nhe->nh_encap) {
+                       err = -ENOMEM;
+                       goto out_err;
+               }
+               memcpy(nhe->nh_encap, tb[NHA_ENCAP],
+                      RTA_LENGTH(RTA_PAYLOAD(tb[NHA_ENCAP])));
+               memcpy(&nhe->nh_encap_type, tb[NHA_ENCAP_TYPE],
+                      sizeof(nhe->nh_encap_type));
+       }
+
+       if (tb[NHA_GROUP]) {
+               if (!__valid_nh_group_attr(tb[NHA_GROUP])) {
+                       fprintf(fp, "<nexthop id %u invalid nexthop group>",
+                               nhe->nh_id);
+                       err = -EINVAL;
+                       goto out_err;
+               }
+
+               nhe->nh_groups = malloc(RTA_PAYLOAD(tb[NHA_GROUP]));
+               if (!nhe->nh_groups) {
+                       err = -ENOMEM;
+                       goto out_err;
+               }
+               nhe->nh_groups_cnt = RTA_PAYLOAD(tb[NHA_GROUP]) /
+                                    sizeof(struct nexthop_grp);
+               memcpy(nhe->nh_groups, RTA_DATA(tb[NHA_GROUP]),
+                      RTA_PAYLOAD(tb[NHA_GROUP]));
+       }
+
+       if (tb[NHA_RES_GROUP]) {
+               parse_nh_res_group_rta(tb[NHA_RES_GROUP], &nhe->nh_res_grp);
+               nhe->nh_has_res_grp = true;
+       }
+
+       nhe->nh_blackhole = !!tb[NHA_BLACKHOLE];
+       nhe->nh_fdb = !!tb[NHA_FDB];
+
+       nhe->nh_family = nhm->nh_family;
+       nhe->nh_protocol = nhm->nh_protocol;
+       nhe->nh_scope = nhm->nh_scope;
+       nhe->nh_flags = nhm->nh_flags;
+
+       return 0;
+
+out_err:
+       ipnh_destroy_entry(nhe);
+       return err;
+}
+
 int print_nexthop(struct nlmsghdr *n, void *arg)
 {
        struct nhmsg *nhm = NLMSG_DATA(n);
-       struct rtattr *tb[NHA_MAX+1];
        FILE *fp = (FILE *)arg;
-       int len;
+       struct nh_entry nhe;
+       int len, err;
 
        SPRINT_BUF(b1);
 
@@ -366,60 +457,61 @@ int print_nexthop(struct nlmsghdr *n, void *arg)
        if (filter.proto && filter.proto != nhm->nh_protocol)
                return 0;
 
-       parse_rtattr_flags(tb, NHA_MAX, RTM_NHA(nhm), len, NLA_F_NESTED);
-
+       err = ipnh_parse_nhmsg(fp, nhm, len, &nhe);
+       if (err) {
+               close_json_object();
+               fprintf(stderr, "Error parsing nexthop: %s\n", strerror(-err));
+               return -1;
+       }
        open_json_object(NULL);
 
        if (n->nlmsg_type == RTM_DELNEXTHOP)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 
-       if (tb[NHA_ID])
-               print_uint(PRINT_ANY, "id", "id %u ",
-                          rta_getattr_u32(tb[NHA_ID]));
+       print_uint(PRINT_ANY, "id", "id %u ", nhe.nh_id);
 
-       if (tb[NHA_GROUP])
-               print_nh_group(fp, tb[NHA_GROUP]);
+       if (nhe.nh_groups)
+               print_nh_group(&nhe);
 
-       if (tb[NHA_GROUP_TYPE])
-               print_nh_group_type(fp, tb[NHA_GROUP_TYPE]);
+       print_nh_group_type(nhe.nh_grp_type);
 
-       if (tb[NHA_RES_GROUP]) {
-               struct nha_res_grp res_grp;
+       if (nhe.nh_has_res_grp)
+               print_nh_res_group(&nhe.nh_res_grp);
 
-               parse_nh_res_group_rta(tb[NHA_RES_GROUP], &res_grp);
-               print_nh_res_group(&res_grp);
-       }
+       if (nhe.nh_encap)
+               lwt_print_encap(fp, &nhe.nh_encap_type.rta, nhe.nh_encap);
 
-       if (tb[NHA_ENCAP])
-               lwt_print_encap(fp, tb[NHA_ENCAP_TYPE], tb[NHA_ENCAP]);
+       if (nhe.nh_gateway_len)
+               __print_rta_gateway(fp, nhe.nh_family,
+                                   format_host(nhe.nh_family,
+                                   nhe.nh_gateway_len,
+                                   &nhe.nh_gateway));
 
-       if (tb[NHA_GATEWAY])
-               print_rta_gateway(fp, nhm->nh_family, tb[NHA_GATEWAY]);
+       if (nhe.nh_oif)
+               print_rta_ifidx(fp, nhe.nh_oif, "dev");
 
-       if (tb[NHA_OIF])
-               print_rta_ifidx(fp, rta_getattr_u32(tb[NHA_OIF]), "dev");
-
-       if (nhm->nh_scope != RT_SCOPE_UNIVERSE || show_details > 0) {
+       if (nhe.nh_scope != RT_SCOPE_UNIVERSE || show_details > 0) {
                print_string(PRINT_ANY, "scope", "scope %s ",
-                            rtnl_rtscope_n2a(nhm->nh_scope, b1, sizeof(b1)));
+                            rtnl_rtscope_n2a(nhe.nh_scope, b1, sizeof(b1)));
        }
 
-       if (tb[NHA_BLACKHOLE])
+       if (nhe.nh_blackhole)
                print_null(PRINT_ANY, "blackhole", "blackhole ", NULL);
 
-       if (nhm->nh_protocol != RTPROT_UNSPEC || show_details > 0) {
+       if (nhe.nh_protocol != RTPROT_UNSPEC || show_details > 0) {
                print_string(PRINT_ANY, "protocol", "proto %s ",
-                            rtnl_rtprot_n2a(nhm->nh_protocol, b1, sizeof(b1)));
+                            rtnl_rtprot_n2a(nhe.nh_protocol, b1, sizeof(b1)));
        }
 
-       print_rt_flags(fp, nhm->nh_flags);
+       print_rt_flags(fp, nhe.nh_flags);
 
-       if (tb[NHA_FDB])
+       if (nhe.nh_fdb)
                print_null(PRINT_ANY, "fdb", "fdb", NULL);
 
        print_string(PRINT_FP, NULL, "%s", "\n");
        close_json_object();
        fflush(fp);
+       ipnh_destroy_entry(&nhe);
 
        return 0;
 }