lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 222 insertions, 0 deletions

diff --git a/lib/mlibc/options/posix/generic/services.cpp b/lib/mlibc/options/posix/generic/services.cpp
new file mode 100644
index 0000000..8ae0656
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/services.cpp
@@ -0,0 +1,222 @@
+#include <mlibc/services.hpp>
+#include <netdb.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <mlibc/debug.hpp>
+
+namespace mlibc {
+
+static int parse_rest(service_buf &buf, char *end, int proto) {
+	if (!strncmp(end, "/udp", 4)) {
+		if (proto == IPPROTO_TCP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_UDP;
+		buf.socktype = SOCK_DGRAM;
+	} else if (!strncmp(end, "/tcp", 4)) {
+		if (proto == IPPROTO_UDP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_TCP;
+		buf.socktype = SOCK_STREAM;
+	} else {
+		return 0;
+	}
+
+	//TODO(geert): also parse aliases.
+
+	return 1;
+}
+
+static int lookup_serv_file_port(service_result &buf, int proto, int port) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line_buf[129] = {0};
+	char *line = line_buf + 1;
+	while(fgets(line, 128, file)) {
+		int name_length = 0;
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		char *end = NULL;
+		for (pos = line; *pos; pos++) {
+			for (; isalpha(*pos); pos++);
+			int rport = strtoul(pos, &end, 10);
+			if (rport != port || rport > 65535) {
+				pos = end;
+				continue;
+			}
+
+			// We have found the port, time to rewind to the start
+			// of the line.
+			for (; pos[-1]; pos--)
+				if(!isspace(pos[-1]))
+					name_length++;
+			break;
+		}
+
+		if (!pos)
+			continue;
+
+		if (!name_length)
+			continue;
+
+		auto name = frg::string<MemoryAllocator>(pos, name_length,
+				getAllocator());
+
+		struct service_buf sbuf = {};
+		sbuf.port = port;
+		sbuf.name = std::move(name);
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+		buf.push_back(std::move(sbuf));
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+static int lookup_serv_file_name(service_result &buf, const char *name,
+		int proto) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line[128];
+	int name_length = strlen(name);
+	while(fgets(line, 128, file)) {
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		for (pos = line; (pos = strstr(pos, name)); pos++) {
+			// the name must start and end with a space
+			if (pos > line && !isspace(pos[-1]))
+				continue;
+			if (pos[name_length] && !isspace(pos[name_length]))
+				continue;
+			break;
+		}
+		if (!pos)
+			continue;
+
+		// Skip the name at the beginning of the line.
+		for(pos = line; *pos && !isspace(*pos); pos++)
+			;
+
+		char *end = NULL;
+		int port = strtoul(pos, &end, 10);
+		if (port > 65535 || end == pos)
+			continue;
+
+		struct service_buf sbuf;
+		sbuf.port = port;
+		sbuf.name = frg::string<MemoryAllocator>(name, getAllocator());
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+
+		buf.push_back(sbuf);
+
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+
+// This function returns a negative error code, since a positive
+// return code means success.
+int lookup_serv_by_name(service_result &buf, const char *name, int proto,
+		int socktype, int flags) {
+	switch(socktype) {
+		case SOCK_STREAM:
+			if (!proto)
+				proto = IPPROTO_TCP;
+			else if (proto != IPPROTO_TCP)
+				return -EAI_SERVICE;
+			break;
+		case SOCK_DGRAM:
+			if (!proto)
+				proto = IPPROTO_UDP;
+			else if (proto != IPPROTO_UDP)
+				return -EAI_SERVICE;
+			break;
+		case 0:
+			break;
+		default:
+			if (name)
+				return -EAI_SERVICE;
+			buf[0].port = 0;
+			buf[0].socktype = socktype;
+			buf[0].protocol = proto;
+			return 1;
+	}
+
+	char *end = nullptr;
+	unsigned int port = 0;
+	int count = 0;
+
+	if (name) {
+		if (!*name)
+			return -EAI_SERVICE;
+		port = strtoul(name, &end, 10);
+	}
+	// The end pointer is a null pointer so the name was a port
+	// or the name was not specified.
+	if (!end || !*end) {
+		if (proto != IPPROTO_UDP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_TCP;
+			buf[count].socktype = SOCK_STREAM;
+			count++;
+		}
+		if (proto != IPPROTO_TCP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_UDP;
+			buf[count].socktype = SOCK_DGRAM;
+			count++;
+		}
+		return count;
+	}
+
+	if (flags & AI_NUMERICSERV)
+		return -EAI_NONAME;
+
+	return lookup_serv_file_name(buf, name, proto);
+}
+
+int lookup_serv_by_port(service_result &buf, int proto, int port) {
+	return lookup_serv_file_port(buf, proto, port);
+}
+
+} // namespace mlibc