From 1ef6da7de4fdec69fbe44d8bdc28cb8acb2df2eb Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Thu, 13 Jan 2022 12:55:27 +0100
Subject: [PATCH] sys/net/sock_util: add sock_tl_name2ep()

---
 sys/include/net/sock/util.h | 16 ++++++++++++++
 sys/net/sock/sock_util.c    | 42 +++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/sys/include/net/sock/util.h b/sys/include/net/sock/util.h
index 9f5336a34b..68d87d25df 100644
--- a/sys/include/net/sock/util.h
+++ b/sys/include/net/sock/util.h
@@ -116,6 +116,22 @@ int sock_urlsplit(const char *url, char *hostport, char *urlpath);
  */
 int sock_tl_str2ep(struct _sock_tl_ep *ep_out, const char *str);
 
+/**
+ * @brief   Convert string to common IP-based transport layer endpoint
+ *          If the `sock_dns` module is used, this will do a DNS lookup
+ *          if @p str is not an IP address.
+ *
+ * Takes eg., "riot-os.org:1234" and converts it into the corresponding
+ * endpoint structure.
+ *
+ * @param[out]  ep_out  endpoint structure to fill
+ * @param[in]   str     string to read from
+ *
+ * @returns     0 on success
+ * @returns     <0 otherwise
+ */
+int sock_tl_name2ep(struct _sock_tl_ep *ep_out, const char *str);
+
 /**
  * @brief    Convert string to TCP endpoint
  *
diff --git a/sys/net/sock/sock_util.c b/sys/net/sock/sock_util.c
index 1fb496a4eb..3bd760c066 100644
--- a/sys/net/sock/sock_util.c
+++ b/sys/net/sock/sock_util.c
@@ -28,6 +28,9 @@
 
 #include "net/sock/udp.h"
 #include "net/sock/util.h"
+#ifdef MODULE_SOCK_DNS
+#include "net/sock/dns.h"
+#endif
 
 #ifdef MODULE_FMT
 #include "fmt.h"
@@ -254,6 +257,45 @@ int sock_tl_str2ep(struct _sock_tl_ep *ep_out, const char *str)
     return -EINVAL;
 }
 
+int sock_tl_name2ep(struct _sock_tl_ep *ep_out, const char *str)
+{
+    int res = sock_tl_str2ep(ep_out, str);
+    if (res == 0) {
+        return 0;
+    }
+
+#if defined(MODULE_SOCK_DNS)
+    char hostbuf[CONFIG_SOCK_HOSTPORT_MAXLEN];
+    const char *host;
+    char *hostend = strchr(str, ':');
+    if (hostend == NULL) {
+        host = str;
+        ep_out->port = 0;
+    } else {
+        size_t host_len = hostend - str;
+        if (host_len >= sizeof(hostbuf)) {
+            return -EINVAL;
+        }
+        memcpy(hostbuf, str, host_len);
+        hostbuf[host_len] = 0;
+        host = hostbuf;
+        ep_out->port = atoi(hostend + 1);;
+    }
+
+    switch (sock_dns_query(host, &ep_out->addr, AF_UNSPEC)) {
+    case 4:
+        ep_out->family = AF_INET;
+        return 0;
+    case 16:
+        ep_out->family = AF_INET6;
+        return 0;
+    default:
+        return -EINVAL;
+    }
+#endif
+    return res;
+}
+
 bool sock_tl_ep_equal(const struct _sock_tl_ep *a,
                       const struct _sock_tl_ep *b)
 {