Fix various socket header usages on MUSL.

Upstream-status: Cleanup needed
--- libparistraceroute-0.93.orig/libparistraceroute/protocols/ipv6.c
+++ libparistraceroute-0.93/libparistraceroute/protocols/ipv6.c
@@ -186,7 +186,7 @@
     // If at least one byte of the src_ip is not null, we suppose
     // that the src_ip has been set...
     for (i = 0; i < 8 && !do_update_src_ip; i++) {
-        if (iph->ip6_src.__in6_u.__u6_addr16[i] != 0) {
+        if (iph->ip6_src.__in6_union.__s6_addr16[i] != 0) {
             do_update_src_ip = false;
             break;
         }
--- libparistraceroute-0.93.orig/libparistraceroute/protocols/tcp.c
+++ libparistraceroute-0.93/libparistraceroute/protocols/tcp.c
@@ -77,6 +77,7 @@
 #define TCP_FIELD_OPTIONS              "options" // if data offset > 5, padded at the end with 0 if necessary
 
 // BSD/Linux abstraction
+#define __FAVOR_BSD
 #ifdef __FAVOR_BSD
 #    define SRC_PORT    th_sport
 #    define DST_PORT    th_dport
@@ -308,10 +309,10 @@
     memcpy(psh + size_ip, tcp_segment, size_tcp);
 
     // Overrides the TCP checksum in psh with zeros
-    memset(psh + size_ip + offsetof(struct tcphdr, check), 0, sizeof(uint16_t));
+    memset(psh + size_ip + offsetof(struct tcphdr, CHECKSUM), 0, sizeof(uint16_t));
 
     // Compute the checksum
-    tcp_header->check = csum((const uint16_t *) psh, size_psh);
+    tcp_header->CHECKSUM = csum((const uint16_t *) psh, size_psh);
     free(psh);
     return true;
 }
--- libparistraceroute-0.93.orig/libparistraceroute/protocols/udp.c
+++ libparistraceroute-0.93/libparistraceroute/protocols/udp.c
@@ -32,6 +32,7 @@
 // XXX UDP parsing missing
 
 // BSD/Linux abstraction
+#define __FAVOR_BSD
 #ifdef __FAVOR_BSD
 #    define SRC_PORT uh_sport
 #    define DST_PORT uh_dport
@@ -147,7 +148,7 @@
     memset(psh + size_ip + offsetof(struct udphdr, CHECKSUM), 0, sizeof(uint16_t));
 
     // Compute the checksum
-    udp_header->check = csum((const uint16_t *) psh, size_psh);
+    udp_header->CHECKSUM = csum((const uint16_t *) psh, size_psh);
     free(psh);
     return true;
 }