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.

6 files changed, 93 insertions, 25 deletions

diff --git a/src/cmd/netstack/util.c b/src/cmd/netstack/util.c
index 68092aa..093c5ac 100644
--- a/src/cmd/netstack/util.c
+++ b/src/cmd/netstack/util.c
@@ -43,6 +43,7 @@ uint16_t ip_checksumphdr(
 }
 
 int ip_parse(const char *s, uint32_t *dest) {
+	// TODO use inet_aton
 	if (!s) return -1;
 
 	uint32_t ip = strtol(s, (char**)&s, 0);
diff --git a/src/libc/arpainet.c b/src/libc/arpainet.c
deleted file mode 100644
index 125a855..0000000
--- a/src/libc/arpainet.c
+++ /dev/null
@@ -1,20 +0,0 @@
-#include <arpa/inet.h>
-
-uint32_t htonl(uint32_t n) {
-	return ((n & 0xFF000000) >> 24)
-	     | ((n & 0x00FF0000) >>  8)
-	     | ((n & 0x0000FF00) <<  8)
-	     | ((n & 0x000000FF) << 24);
-}
-
-uint16_t htons(uint16_t n) {
-	return (n >> 8) | (n << 8);
-}
-
-uint32_t ntohl(uint32_t n) {
-	return htonl(n);
-}
-
-uint16_t ntohs(uint16_t n) {
-	return htons(n);
-}
diff --git a/src/libc/include/arpa/inet.h b/src/libc/include/arpa/inet.h
index d372467..1e4f97e 100644
--- a/src/libc/include/arpa/inet.h
+++ b/src/libc/include/arpa/inet.h
@@ -1,4 +1,5 @@
 #pragma once
+#include <netinet/in.h>
 #include <stdint.h>
 
 uint32_t htonl(uint32_t n);
@@ -6,3 +7,5 @@ uint16_t htons(uint16_t n);
 
 uint32_t ntohl(uint32_t n);
 uint16_t ntohs(uint16_t n);
+
+int inet_aton(const char *s, struct in_addr *dest);
diff --git a/src/libc/net/arpainet.c b/src/libc/net/arpainet.c
new file mode 100644
index 0000000..62efb62
--- /dev/null
+++ b/src/libc/net/arpainet.c
@@ -0,0 +1,38 @@
+#include <arpa/inet.h>
+#include <stdlib.h>
+
+uint32_t htonl(uint32_t n) {
+	return ((n & 0xFF000000) >> 24)
+	     | ((n & 0x00FF0000) >>  8)
+	     | ((n & 0x0000FF00) <<  8)
+	     | ((n & 0x000000FF) << 24);
+}
+
+uint16_t htons(uint16_t n) {
+	return (n >> 8) | (n << 8);
+}
+
+uint32_t ntohl(uint32_t n) {
+	return htonl(n);
+}
+
+uint16_t ntohs(uint16_t n) {
+	return htons(n);
+}
+
+int inet_aton(const char *s, struct in_addr *dest) {
+	if (!s) return -1;
+
+	uint32_t ip = strtol(s, (char**)&s, 0);
+	int parts = 1;
+	for (; parts < 4; parts++) {
+		if (!*s) break;
+		if (*s++ != '.') return 0;
+		ip <<= 8;
+		ip += strtol(s, (char**)&s, 0);
+	}
+	if (parts > 1)
+		ip = ((ip & 0xFFFFFF00) << 8 * (4 - parts)) | (ip & 0xFF);
+	dest->s_addr = htonl(ip);
+	return 1;
+}
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;
+}
diff --git a/src/libc/socket.c b/src/libc/net/socket.c
index 5ea7266..9eacbe5 100644
--- a/src/libc/socket.c
+++ b/src/libc/net/socket.c
@@ -89,8 +89,3 @@ int getsockname(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
 	addr->sa_family = AF_UNSPEC;
 	return 0;
 }
-
-struct hostent *gethostbyname(const char *name) {
-	(void)name;
-	return NULL;
-}