Add initial JID parsing

1 files changed, 57 insertions, 0 deletions

diff --git a/src/rexmpp_jid.c b/src/rexmpp_jid.c
new file mode 100644
index 0000000..44e2754
--- /dev/null
+++ b/src/rexmpp_jid.c
@@ -0,0 +1,57 @@
+/**
+   @file rexmpp_jid.c
+   @brief JID parsing and manipulation
+   @author defanor <defanor@uberspace.net>
+   @date 2020
+   @copyright MIT license.
+*/
+
+#include <stddef.h>
+#include <string.h>
+#include "rexmpp_jid.h"
+
+int rexmpp_jid_parse (const char *str, struct rexmpp_jid *jid) {
+  const char *resource = NULL, *domain = NULL;
+  size_t i;
+  size_t resource_len = 0, local_len = 0;
+  size_t domain_len, bare_len, full_len = strlen(str);
+  domain_len = full_len;
+  bare_len = full_len;
+
+  /* Find the separators. */
+  for (i = 0; i < full_len; i++) {
+    if (local_len == 0 && str[i] == '@') {
+      local_len = i;
+      domain_len -= local_len + 1;
+      domain = str + i + 1;
+    }
+    if (str[i] == '/') {
+      resource_len = full_len - i - 1;
+      domain_len -= resource_len + 1;
+      bare_len -= resource_len + 1;
+      resource = str + i + 1;
+      break;
+    }
+  }
+
+  /* Check all the lengths. */
+  if (full_len > 3071 || bare_len > 2047 ||
+      local_len > 1023 || resource_len > 1023 ||
+      domain_len > 1023 || domain_len < 1) {
+    return -1;
+  }
+
+  /* Copy all the parts. */
+  strncpy(jid->full, str, full_len);
+  jid->full[full_len] = '\0';
+  strncpy(jid->bare, str, bare_len);
+  jid->bare[bare_len] = '\0';
+  strncpy(jid->local, str, local_len);
+  jid->local[local_len] = '\0';
+  strncpy(jid->domain, domain, domain_len);
+  jid->domain[domain_len] = '\0';
+  strncpy(jid->resource, resource, resource_len);
+  jid->resource[resource_len] = '\0';
+
+  return 0;
+}