[PATCH iproute2(-next) v2 1/1] ip: fix ip route show json output for multipath nexthops

[Julien Fortin]

From: Julien Fortin <jul...@cumulusnetworks.com>

print_rta_multipath doesn't support JSON output:

{
    "dst":"27.0.0.13",
    "protocol":"bgp",
    "metric":20,
    "flags":[],
    "gateway":"169.254.0.1"dev uplink-1 weight 1 ,
    "flags":["onlink"],
    "gateway":"169.254.0.1"dev uplink-2 weight 1 ,
    "flags":["onlink"]
},

since RTA_MULTIPATH has nested objects we should print them
in a json array.

With the path we have the following output:

{
    "flags": [],
    "dst": "36.0.0.13",
    "protocol": "bgp",
    "metric": 20,
    "nexthops": [
        {
            "weight": 1,
            "flags": [
                "onlink"
            ],
            "gateway": "169.254.0.1",
            "dev": "uplink-1"
        },
        {
            "weight": 1,
            "flags": [
                "onlink"
            ],
            "gateway": "169.254.0.1",
            "dev": "uplink-2"
        }
    ]
}

Fixes: 663c3cb23103f4 ("iproute: implement JSON and color output")

Signed-off-by: Julien Fortin <jul...@cumulusnetworks.com>
---
 ip/iproute.c | 46 ++++++++++++++++++++++++++++------------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/ip/iproute.c b/ip/iproute.c
index a4533851..32bb52df 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -649,24 +649,26 @@ static void print_rta_multipath(FILE *fp, const struct 
rtmsg *r,
        int len = RTA_PAYLOAD(rta);
        int first = 1;
 
+       open_json_array(PRINT_JSON, "nexthops");
+
        while (len >= sizeof(*nh)) {
                struct rtattr *tb[RTA_MAX + 1];
 
                if (nh->rtnh_len > len)
                        break;
 
-               if (!is_json_context()) {
-                       if ((r->rtm_flags & RTM_F_CLONED) &&
-                           r->rtm_type == RTN_MULTICAST) {
-                               if (first) {
-                                       fprintf(fp, "Oifs: ");
-                                       first = 0;
-                               } else {
-                                       fprintf(fp, " ");
-                               }
-                       } else
-                               fprintf(fp, "%s\tnexthop ", _SL_);
-               }
+               open_json_object(NULL);
+
+               if ((r->rtm_flags & RTM_F_CLONED) &&
+                   r->rtm_type == RTN_MULTICAST) {
+                       if (first) {
+                               print_string(PRINT_FP, NULL, "Oifs: ", NULL);
+                               first = 0;
+                       } else {
+                               print_string(PRINT_FP, NULL, " ", NULL);
+                       }
+               } else
+                       print_string(PRINT_FP, NULL, "%s\tnexthop ", _SL_);
 
                if (nh->rtnh_len > sizeof(*nh)) {
                        parse_rtattr(tb, RTA_MAX, RTNH_DATA(nh),
@@ -689,22 +691,30 @@ static void print_rta_multipath(FILE *fp, const struct 
rtmsg *r,
 
                if ((r->rtm_flags & RTM_F_CLONED) &&
                    r->rtm_type == RTN_MULTICAST) {
-                       fprintf(fp, "%s", ll_index_to_name(nh->rtnh_ifindex));
+                       print_string(PRINT_ANY, "dev",
+                                    "%s", ll_index_to_name(nh->rtnh_ifindex));
+
                        if (nh->rtnh_hops != 1)
-                               fprintf(fp, "(ttl>%d)", nh->rtnh_hops);
-                       fprintf(fp, " ");
+                               print_int(PRINT_ANY, "ttl", "(ttl>%d)", 
nh->rtnh_hops);
+
+                       print_string(PRINT_FP, NULL, " ", NULL);
                } else {
-                       fprintf(fp, "dev %s ", 
ll_index_to_name(nh->rtnh_ifindex));
+                       print_string(PRINT_ANY, "dev",
+                                    "dev %s ", 
ll_index_to_name(nh->rtnh_ifindex));
+
                        if (r->rtm_family != AF_MPLS)
-                               fprintf(fp, "weight %d ",
-                                       nh->rtnh_hops+1);
+                               print_int(PRINT_ANY, "weight",
+                                         "weight %d ", nh->rtnh_hops + 1);
                }
 
                print_rt_flags(fp, nh->rtnh_flags);
 
                len -= NLMSG_ALIGN(nh->rtnh_len);
                nh = RTNH_NEXT(nh);
+
+               close_json_object();
        }
+       close_json_array(PRINT_JSON, NULL);
 }
 
 int print_route(struct nlmsghdr *n, void *arg)
-- 
2.23.0