Factorizing out function split_host_port.

1 files changed, 58 insertions, 0 deletions

diff --git a/src/core/support/host_port.c b/src/core/support/host_port.c
index 379d30b045..fa49f1a33a 100644
--- a/src/core/support/host_port.c
+++ b/src/core/support/host_port.c
@@ -36,6 +36,7 @@
 #include <string.h>
 
 #include "src/core/support/string.h"
+#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
 int gpr_join_host_port(char **out, const char *host, int port) {
@@ -47,3 +48,60 @@ int gpr_join_host_port(char **out, const char *host, int port) {
     return gpr_asprintf(out, "%s:%d", host, port);
   }
 }
+
+void gpr_split_host_port(const char *name, char **host, char **port) {
+  const char *host_start;
+  size_t host_len;
+  const char *port_start;
+
+  *host = NULL;
+  *port = NULL;
+
+  if (name[0] == '[') {
+    /* Parse a bracketed host, typically an IPv6 literal. */
+    const char *rbracket = strchr(name, ']');
+    if (rbracket == NULL) {
+      /* Unmatched [ */
+      return;
+    }
+    if (rbracket[1] == '\0') {
+      /* ]<end> */
+      port_start = NULL;
+    } else if (rbracket[1] == ':') {
+      /* ]:<port?> */
+      port_start = rbracket + 2;
+    } else {
+      /* ]<invalid> */
+      return;
+    }
+    host_start = name + 1;
+    host_len = rbracket - host_start;
+    if (memchr(host_start, ':', host_len) == NULL) {
+      /* Require all bracketed hosts to contain a colon, because a hostname or
+      IPv4 address should never use brackets. */
+      return;
+    }
+  } else {
+    const char *colon = strchr(name, ':');
+    if (colon != NULL && strchr(colon + 1, ':') == NULL) {
+      /* Exactly 1 colon.  Split into host:port. */
+      host_start = name;
+      host_len = colon - name;
+      port_start = colon + 1;
+    } else {
+      /* 0 or 2+ colons.  Bare hostname or IPv6 litearal. */
+      host_start = name;
+      host_len = strlen(name);
+      port_start = NULL;
+    }
+  }
+
+  /* Allocate return values. */
+  *host = gpr_malloc(host_len + 1);
+  memcpy(*host, host_start, host_len);
+  (*host)[host_len] = '\0';
+
+  if (port_start != NULL) {
+    *port = gpr_strdup(port_start);
+  }
+}