Add a "fork" of musl as //fusl.

fusl/src/network/lookup_serv.c

+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <ctype.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include "lookup.h"
+#include "stdio_impl.h"
+
+int __lookup_serv(struct service buf[static MAXSERVS], const char *name, int proto, int socktype, int flags)
+{
+        char line[128];
+        int cnt = 0;
+        char *p, *z = "";
+        unsigned long port = 0;
+
+        switch (socktype) {
+        case SOCK_STREAM:
+                switch (proto) {
+                case 0:
+                        proto = IPPROTO_TCP;
+                case IPPROTO_TCP:
+                        break;
+                default:
+                        return EAI_SERVICE;
+                }
+                break;
+        case SOCK_DGRAM:
+                switch (proto) {
+                case 0:
+                        proto = IPPROTO_UDP;
+                case IPPROTO_UDP:
+                        break;
+                default:
+                        return EAI_SERVICE;
+                }
+        case 0:
+                break;
+        default:
+                if (name) return EAI_SERVICE;
+                buf[0].port = 0;
+                buf[0].proto = proto;
+                buf[0].socktype = socktype;
+                return 1;
+        }
+
+        if (name) {
+                if (!*name) return EAI_SERVICE;
+                port = strtoul(name, &z, 10);
+        }
+        if (!*z) {
+                if (port > 65535) return EAI_SERVICE;
+                if (proto != IPPROTO_UDP) {
+                        buf[cnt].port = port;
+                        buf[cnt].socktype = SOCK_STREAM;
+                        buf[cnt++].proto = IPPROTO_TCP;
+                }
+                if (proto != IPPROTO_TCP) {
+                        buf[cnt].port = port;
+                        buf[cnt].socktype = SOCK_DGRAM;
+                        buf[cnt++].proto = IPPROTO_UDP;
+                }
+                return cnt;
+        }
+
+        if (flags & AI_NUMERICSERV) return EAI_SERVICE;
+
+        size_t l = strlen(name);
+
+        unsigned char _buf[1032];
+        FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
+        if (!f) switch (errno) {
+        case ENOENT:
+        case ENOTDIR:
+        case EACCES:
+                return EAI_SERVICE;
+        default:
+                return EAI_SYSTEM;
+        }
+
+        while (fgets(line, sizeof line, f) && cnt < MAXSERVS) {
+                if ((p=strchr(line, '#'))) *p++='\n', *p=0;
+
+                /* Find service name */
+                for(p=line; (p=strstr(p, name)); p++) {
+                        if (p>line && !isspace(p[-1])) continue;
+                        if (p[l] && !isspace(p[l])) continue;
+                        break;
+                }
+                if (!p) continue;
+
+                /* Skip past canonical name at beginning of line */
+                for (p=line; *p && !isspace(*p); p++);
+
+                port = strtoul(p, &z, 10);
+                if (port > 65535 || z==p) continue;
+                if (!strncmp(z, "/udp", 4)) {
+                        if (proto == IPPROTO_TCP) continue;
+                        buf[cnt].port = port;
+                        buf[cnt].socktype = SOCK_DGRAM;
+                        buf[cnt++].proto = IPPROTO_UDP;
+                }
+                if (!strncmp(z, "/tcp", 4)) {
+                        if (proto == IPPROTO_UDP) continue;
+                        buf[cnt].port = port;
+                        buf[cnt].socktype = SOCK_STREAM;
+                        buf[cnt++].proto = IPPROTO_TCP;
+                }
+        }
+        __fclose_ca(f);
+        return cnt > 0 ? cnt : EAI_SERVICE;
+}