Implement the FDR forwarder proxy service used during restore of recent iOS versions.

1 files changed, 392 insertions, 0 deletions

diff --git a/src/socket.c b/src/socket.c
new file mode 100644
index 0000000..c35de33
--- /dev/null
+++ b/src/socket.c
@@ -0,0 +1,392 @@
+/*
+ * socket.c
+ *
+ * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
+ * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#ifdef WIN32
+#include <winsock2.h>
+#include <windows.h>
+static int wsa_init = 0;
+#else
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#endif
+#include "socket.h"
+
+#define RECV_TIMEOUT 20000
+
+static int verbose = 0;
+
+void socket_set_verbose(int level)
+{
+	verbose = level;
+}
+
+#ifndef WIN32
+int socket_create_unix(const char *filename)
+{
+	struct sockaddr_un name;
+	int sock;
+	size_t size;
+
+	// remove if still present
+	unlink(filename);
+
+	/* Create the socket. */
+	sock = socket(PF_LOCAL, SOCK_STREAM, 0);
+	if (sock < 0) {
+		perror("socket");
+		return -1;
+	}
+
+	/* Bind a name to the socket. */
+	name.sun_family = AF_LOCAL;
+	strncpy(name.sun_path, filename, sizeof(name.sun_path));
+	name.sun_path[sizeof(name.sun_path) - 1] = '\0';
+
+	/* The size of the address is
+	   the offset of the start of the filename,
+	   plus its length,
+	   plus one for the terminating null byte.
+	   Alternatively you can just do:
+	   size = SUN_LEN (&name);
+	 */
+	size = (offsetof(struct sockaddr_un, sun_path)
+			+ strlen(name.sun_path) + 1);
+
+	if (bind(sock, (struct sockaddr *) &name, size) < 0) {
+		perror("bind");
+		socket_close(sock);
+		return -1;
+	}
+
+	if (listen(sock, 10) < 0) {
+		perror("listen");
+		socket_close(sock);
+		return -1;
+	}
+
+	return sock;
+}
+
+int socket_connect_unix(const char *filename)
+{
+	struct sockaddr_un name;
+	int sfd = -1;
+	size_t size;
+	struct stat fst;
+
+	// check if socket file exists...
+	if (stat(filename, &fst) != 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: stat '%s': %s\n", __func__, filename,
+					strerror(errno));
+		return -1;
+	}
+	// ... and if it is a unix domain socket
+	if (!S_ISSOCK(fst.st_mode)) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: File '%s' is not a socket!\n", __func__,
+					filename);
+		return -1;
+	}
+	// make a new socket
+	if ((sfd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
+		return -1;
+	}
+	// and connect to 'filename'
+	name.sun_family = AF_LOCAL;
+	strncpy(name.sun_path, filename, sizeof(name.sun_path));
+	name.sun_path[sizeof(name.sun_path) - 1] = 0;
+
+	size = (offsetof(struct sockaddr_un, sun_path)
+			+ strlen(name.sun_path) + 1);
+
+	if (connect(sfd, (struct sockaddr *) &name, size) < 0) {
+		socket_close(sfd);
+		if (verbose >= 2)
+			fprintf(stderr, "%s: connect: %s\n", __func__,
+					strerror(errno));
+		return -1;
+	}
+
+	return sfd;
+}
+#endif
+
+int socket_create(uint16_t port)
+{
+	int sfd = -1;
+	int yes = 1;
+#ifdef WIN32
+	WSADATA wsa_data;
+	if (!wsa_init) {
+		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
+			fprintf(stderr, "WSAStartup failed!\n");
+			ExitProcess(-1);
+		}
+		wsa_init = 1;
+	}
+#endif
+	struct sockaddr_in saddr;
+
+	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
+		perror("socket()");
+		return -1;
+	}
+
+	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	memset((void *) &saddr, 0, sizeof(saddr));
+	saddr.sin_family = AF_INET;
+	saddr.sin_addr.s_addr = htonl(INADDR_ANY);
+	saddr.sin_port = htons(port);
+
+	if (0 > bind(sfd, (struct sockaddr *) &saddr, sizeof(saddr))) {
+		perror("bind()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	if (listen(sfd, 1) == -1) {
+		perror("listen()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	return sfd;
+}
+
+int socket_connect(const char *addr, uint16_t port)
+{
+	int sfd = -1;
+	int yes = 1;
+	struct hostent *hp;
+	struct sockaddr_in saddr;
+#ifdef WIN32
+	WSADATA wsa_data;
+	if (!wsa_init) {
+		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
+			fprintf(stderr, "WSAStartup failed!\n");
+			ExitProcess(-1);
+		}
+		wsa_init = 1;
+	}
+#endif
+
+	if (!addr) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if ((hp = gethostbyname(addr)) == NULL) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: unknown host '%s'\n", __func__, addr);
+		return -1;
+	}
+
+	if (!hp->h_addr) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: gethostbyname returned NULL address!\n",
+					__func__);
+		return -1;
+	}
+
+	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
+		perror("socket()");
+		return -1;
+	}
+
+	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	memset((void *) &saddr, 0, sizeof(saddr));
+	saddr.sin_family = AF_INET;
+	saddr.sin_addr.s_addr = *(uint32_t *) hp->h_addr;
+	saddr.sin_port = htons(port);
+
+	if (connect(sfd, (struct sockaddr *) &saddr, sizeof(saddr)) < 0) {
+		perror("connect");
+		socket_close(sfd);
+		return -2;
+	}
+
+	return sfd;
+}
+
+int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout)
+{
+	fd_set fds;
+	int sret;
+	int eagain;
+	struct timeval to;
+	struct timeval *pto;
+
+	if (fd <= 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "ERROR: invalid fd in check_fd %d\n", fd);
+		return -1;
+	}
+
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+
+	if (timeout > 0) {
+		to.tv_sec = (time_t) (timeout / 1000);
+		to.tv_usec = (time_t) ((timeout - (to.tv_sec * 1000)) * 1000);
+		pto = &to;
+	} else {
+		pto = NULL;
+	}
+
+	sret = -1;
+
+	do {
+		eagain = 0;
+		switch (fdm) {
+		case FDM_READ:
+			sret = select(fd + 1, &fds, NULL, NULL, pto);
+			break;
+		case FDM_WRITE:
+			sret = select(fd + 1, NULL, &fds, NULL, pto);
+			break;
+		case FDM_EXCEPT:
+			sret = select(fd + 1, NULL, NULL, &fds, pto);
+			break;
+		default:
+			return -1;
+		}
+
+		if (sret < 0) {
+			switch (errno) {
+			case EINTR:
+				// interrupt signal in select
+				if (verbose >= 2)
+					fprintf(stderr, "%s: EINTR\n", __func__);
+				eagain = 1;
+				break;
+			case EAGAIN:
+				if (verbose >= 2)
+					fprintf(stderr, "%s: EAGAIN\n", __func__);
+				break;
+			default:
+				if (verbose >= 2)
+					fprintf(stderr, "%s: select failed: %s\n", __func__,
+							strerror(errno));
+				return -1;
+			}
+		}
+	} while (eagain);
+
+	return sret;
+}
+
+int socket_accept(int fd, uint16_t port)
+{
+#ifdef WIN32
+	int addr_len;
+#else
+	socklen_t addr_len;
+#endif
+	int result;
+	struct sockaddr_in addr;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port = htons(port);
+
+	addr_len = sizeof(addr);
+	result = accept(fd, (struct sockaddr*)&addr, &addr_len);
+
+	return result;
+}
+
+int socket_shutdown(int fd, int how)
+{
+	return shutdown(fd, how);
+}
+
+int socket_close(int fd) {
+#ifdef WIN32
+	return closesocket(fd);
+#else
+	return close(fd);
+#endif
+}
+
+int socket_receive(int fd, void *data, size_t length)
+{
+	return socket_receive_timeout(fd, data, length, 0, RECV_TIMEOUT);
+}
+
+int socket_peek(int fd, void *data, size_t length)
+{
+	return socket_receive_timeout(fd, data, length, MSG_PEEK, RECV_TIMEOUT);
+}
+
+int socket_receive_timeout(int fd, void *data, size_t length, int flags,
+					 unsigned int timeout)
+{
+	int res;
+	int result;
+
+	// check if data is available
+	res = socket_check_fd(fd, FDM_READ, timeout);
+	if (res <= 0) {
+		return res;
+	}
+	// if we get here, there _is_ data available
+	result = recv(fd, data, length, flags);
+	if (res > 0 && result == 0) {
+		// but this is an error condition
+		if (verbose >= 3)
+			fprintf(stderr, "%s: fd=%d recv returned 0\n", __func__, fd);
+		return -EAGAIN;
+	}
+	if (result < 0) {
+		return -errno;
+	}
+	return result;
+}
+
+int socket_send(int fd, void *data, size_t length)
+{
+	return send(fd, data, length, 0);
+}