user/libc: reorganize net stuff, basic hosts-only gethostbyname()

/usr/share/hosts because i don't have /etc/ yet and i don't feel like creating it.

1 files changed, 51 insertions, 0 deletions

diff --git a/src/libc/net/gethostbyname.c b/src/libc/net/gethostbyname.c
new file mode 100644
index 0000000..f2b59c1
--- /dev/null
+++ b/src/libc/net/gethostbyname.c
@@ -0,0 +1,51 @@
+#include <arpa/inet.h>
+#include <ctype.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct hostent *gethostbyname(const char *name) {
+	// TODO ipv4 addresses should just get copied
+	static struct hostent he;
+	static struct in_addr addr;
+	static void *addrs[2] = {NULL, NULL};
+	bool found = false;
+	char buf[256];
+	FILE *fp;
+
+	if (he.h_name) {
+		free(he.h_name);
+		he.h_name = NULL;
+	}
+
+	if ((fp = fopen("/usr/share/hosts", "r")) == NULL) {
+		return NULL;
+	}
+	while (!found && fgets(buf, sizeof buf, fp)) {
+		char *s;
+		if (!isdigit(buf[0])) continue;
+		s = strtok(buf, " \t\n");
+		if (!inet_aton(s, &addr)) continue;
+		while ((s = strtok(NULL, " \t\n"))) {
+			if (strcmp(s, name) == 0) {
+				found = true;
+				break;
+			}
+		}
+	}
+	fclose(fp);
+	if (!found) {
+		return NULL;
+	}
+
+	he.h_name = strdup(name);
+	he.h_aliases = NULL;
+	he.h_addrtype = AF_INET;
+	he.h_length = 4;
+	he.h_addr_list = (void*)&addrs;
+	addrs[0] = &addr.s_addr;
+	return &he;
+}