prepare for different payload dissectors

4 files changed, 125 insertions, 67 deletions

diff --git a/Makefile b/Makefile
index 4ff2901..9978e73 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 LIB_SRCS = utils.c sock_events.c libc_overrides.c
+CFLAGS = -Wall
 
 
 default: libudtrace.so
diff --git a/sock_events.c b/sock_events.c
index 523f45a..9340d7d 100644
--- a/sock_events.c
+++ b/sock_events.c
@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
+#include <sys/un.h>
 #include <unistd.h>
 
 #ifdef __ANDROID__
@@ -25,13 +26,6 @@
 #define IS_OUT	true
 #define IS_IN	false
 
-static void trace_data(int fd, bool is_out, const char *fn, const uint8_t *data, unsigned int len)
-{
-	if (!data || !len)
-		return;
-	fprintf(stderr, "%d %s %c %s\n", fd, fn, is_out ? 'W' : 'R', udtrace_hexdump(data, len, ""));
-}
-
 static void trace_iov(int fd, bool is_out, const char *fn, int ret,
 		      const struct iovec *iovec, int iovec_count)
 {
@@ -46,7 +40,7 @@ static void trace_iov(int fd, bool is_out, const char *fn, int ret,
 		if (remain < vec->iov_len)
 			written_len = remain;
 
-		trace_data(fd, is_out, fn, vec->iov_base, written_len);
+		udtrace_data(fd, is_out, fn, vec->iov_base, written_len);
 
 		remain -= written_len;
 	}
@@ -60,16 +54,26 @@ void sock_ev_socket(int fd, int domain, int type, int protocol)
 {
 	if (domain != AF_UNIX)
 		return;
-	add_fd(fd);
+	udtrace_add_fd(fd);
 }
 
 void sock_ev_bind(int fd, int ret, int err, const struct sockaddr *addr, socklen_t len)
 {
+	const struct sockaddr_un *sun = (const struct sockaddr_un *) addr;
+	if (ret < 0)
+		return;
+	LOG("bind(%d, \"%s\")\n", fd, sun->sun_path);
+	udtrace_fd_set_path(fd, sun->sun_path);
 }
 
 void sock_ev_connect(int fd, int ret, int err, const struct sockaddr *addr,
                      socklen_t len)
 {
+	const struct sockaddr_un *sun = (const struct sockaddr_un *) addr;
+	if (ret < 0)
+		return;
+	LOG("connect(%d, \"%s\")\n", fd, sun->sun_path);
+	udtrace_fd_set_path(fd, sun->sun_path);
 }
 
 void sock_ev_listen(int fd, int ret, int err, int backlog)
@@ -81,7 +85,7 @@ void sock_ev_accept(int fd, int ret, int err, struct sockaddr *addr,
 {
 	if (ret < 0)
 		return;
-	add_fd(ret);
+	udtrace_add_fd(ret);
 }
 
 void sock_ev_accept4(int fd, int ret, int err, struct sockaddr *addr,
@@ -89,7 +93,7 @@ void sock_ev_accept4(int fd, int ret, int err, struct sockaddr *addr,
 {
 	if (ret < 0)
 		return;
-	add_fd(ret);
+	udtrace_add_fd(ret);
 }
 
 void sock_ev_send(int fd, int ret, int err, const void *buf, size_t bytes,
@@ -97,14 +101,14 @@ void sock_ev_send(int fd, int ret, int err, const void *buf, size_t bytes,
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_OUT, "send", buf, ret);
+	udtrace_data(fd, IS_OUT, "send", buf, ret);
 }
 
 void sock_ev_recv(int fd, int ret, int err, void *buf, size_t bytes, int flags)
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_IN, "recv", buf, ret);
+	udtrace_data(fd, IS_IN, "recv", buf, ret);
 }
 
 void sock_ev_sendto(int fd, int ret, int err, const void *buf, size_t bytes,
@@ -112,7 +116,7 @@ void sock_ev_sendto(int fd, int ret, int err, const void *buf, size_t bytes,
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_OUT, "sendto", buf, ret);
+	udtrace_data(fd, IS_OUT, "sendto", buf, ret);
 }
 
 void sock_ev_recvfrom(int fd, int ret, int err, void *buf, size_t bytes,
@@ -120,7 +124,7 @@ void sock_ev_recvfrom(int fd, int ret, int err, void *buf, size_t bytes,
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_IN, "recvfrom", buf, ret);
+	udtrace_data(fd, IS_IN, "recvfrom", buf, ret);
 }
 
 void sock_ev_sendmsg(int fd, int ret, int err, const struct msghdr *msg,
@@ -168,40 +172,40 @@ void sock_ev_write(int fd, int ret, int err, const void *buf, size_t bytes)
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_OUT, "write", buf, ret);
+	udtrace_data(fd, IS_OUT, "write", buf, ret);
 }
 
 void sock_ev_read(int fd, int ret, int err, void *buf, size_t bytes)
 {
 	if (ret <= 0)
 		return;
-	trace_data(fd, IS_IN, "read", buf, ret);
+	udtrace_data(fd, IS_IN, "read", buf, ret);
 }
 
 void sock_ev_close(int fd, int ret, int err)
 {
-	del_fd(fd);
+	udtrace_del_fd(fd);
 }
 
 void sock_ev_dup(int fd, int ret, int err)
 {
 	if (ret >= 0)
-		add_fd(ret);
+		udtrace_add_fd(ret);
 }
 
 void sock_ev_dup2(int fd, int ret, int err, int newfd)
 {
 	if (ret >= 0) {
-		del_fd(newfd);
-		add_fd(ret);
+		udtrace_del_fd(newfd);
+		udtrace_add_fd(ret);
 	}
 }
 
 void sock_ev_dup3(int fd, int ret, int err, int newfd, int flags)
 {
 	if (ret >= 0) {
-		del_fd(newfd);
-		add_fd(ret);
+		udtrace_del_fd(newfd);
+		udtrace_add_fd(ret);
 	}
 }
 
diff --git a/utils.c b/utils.c
index 0c763bc..55499af 100644
--- a/utils.c
+++ b/utils.c
@@ -3,36 +3,77 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 
 #include "utils.h"
 
 #define MAX_UNIX_FDS	32
 
-#define LOG(fmt, args ...) \
-	fprintf(stderr, ">>> UDTRACE: " fmt, ## args)
-
 /***********************************************************************
  * Utility functions
  ***********************************************************************/
 
-static int unix_fds[MAX_UNIX_FDS];
+/* taken from libosmocore */
+static char hexd_buff[4096];
+static const char hex_chars[] = "0123456789abcdef";
+static char *hexdump(const unsigned char *buf, int len, char *delim)
+{
+	int i;
+	char *cur = hexd_buff;
 
-__attribute__ ((constructor)) static void udtrace_init(void) {
+	hexd_buff[0] = 0;
+	for (i = 0; i < len; i++) {
+		const char *delimp = delim;
+		int len_remain = sizeof(hexd_buff) - (cur - hexd_buff);
+		if (len_remain < 3)
+			break;
+
+		*cur++ = hex_chars[buf[i] >> 4];
+		*cur++ = hex_chars[buf[i] & 0xf];
+
+		while (len_remain > 1 && *delimp) {
+			*cur++ = *delimp++;
+			len_remain--;
+		}
+
+		*cur = 0;
+	}
+	hexd_buff[sizeof(hexd_buff)-1] = 0;
+	return hexd_buff;
+}
+
+typedef void (*udtrace_dissector)(int fd, bool is_out, const char *fn, const uint8_t *data, unsigned int len);
+
+static void default_dissector(int fd, bool is_out, const char *fn, const uint8_t *data, unsigned int len)
+{
+	fprintf(stderr, "%d %s %c %s\n", fd, fn, is_out ? 'W' : 'R', hexdump(data, len, ""));
+}
+
+struct sock_state {
+	int fd;
+	const char *path;
+	udtrace_dissector dissector;
+};
+
+static struct sock_state unix_fds[MAX_UNIX_FDS];
+
+__attribute__ ((constructor)) static void udtrace_init(void)
+{
 	int i;
 	LOG("Unix Domain Socket Trace initialized\n");
 	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
-		unix_fds[i] = -1;
+		unix_fds[i] = (struct sock_state) { -1, NULL, NULL };
 	}
 }
 
 /* add a file descriptor from the list of to-be-traced ones */
-void add_fd(int fd)
+void udtrace_add_fd(int fd)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
-		if (unix_fds[i] == -1) {
+		if (unix_fds[i].fd == -1) {
 			LOG("Adding FD %d\n", fd);
-			unix_fds[i] = fd;
+			unix_fds[i].fd = fd;
 			return;
 		}
 	}
@@ -40,56 +81,62 @@ void add_fd(int fd)
 }
 
 /* delete a file descriptor from the list of to-be-traced ones */
-void del_fd(int fd)
+void udtrace_del_fd(int fd)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
-		if (unix_fds[i] == fd) {
+		if (unix_fds[i].fd == fd) {
 			LOG("Removing FD %d\n", fd);
-			unix_fds[i] = -1;
+			free((void *) unix_fds[i].path);
+			unix_fds[i] = (struct sock_state) { -1, NULL, NULL };
 			return;
 		}
 	}
 	LOG("Couldn't delete UNIX FD %d (no such FD)\n", fd);
 }
 
-/* is the given file descriptor part of the to-be-traced unix domain fd's? */
-bool is_unix_socket(int fd)
+static void udtrace_resolve_dissector(struct sock_state *ss)
+{
+	/* FIXME: actual useful dissectors resovled by path */
+	ss->dissector = &default_dissector;
+}
+
+/* set the path of a given fd */
+void udtrace_fd_set_path(int fd, const char *path)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
-		if (unix_fds[i] == fd)
-			return true;
+		if (unix_fds[i].fd == fd) {
+			unix_fds[i].path = strdup(path);
+			udtrace_resolve_dissector(&unix_fds[i]);
+			return;
+		}
 	}
-	return false;
 }
 
-
-/* taken from libosmocore */
-static char hexd_buff[4096];
-static const char hex_chars[] = "0123456789abcdef";
-char *udtrace_hexdump(const unsigned char *buf, int len, char *delim)
+const struct sock_state *udtrace_sstate_by_fd(int fd)
 {
 	int i;
-	char *cur = hexd_buff;
-
-	hexd_buff[0] = 0;
-	for (i = 0; i < len; i++) {
-		const char *delimp = delim;
-		int len_remain = sizeof(hexd_buff) - (cur - hexd_buff);
-		if (len_remain < 3)
-			break;
-
-		*cur++ = hex_chars[buf[i] >> 4];
-		*cur++ = hex_chars[buf[i] & 0xf];
+	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
+		if (unix_fds[i].fd == fd)
+			return &unix_fds[i];
+	}
+	return NULL;
+}
 
-		while (len_remain > 1 && *delimp) {
-			*cur++ = *delimp++;
-			len_remain--;
-		}
+/* is the given file descriptor part of the to-be-traced unix domain fd's? */
+bool is_unix_socket(int fd)
+{
+	if (udtrace_sstate_by_fd(fd))
+		return true;
+	else
+		return false;
+}
 
-		*cur = 0;
-	}
-	hexd_buff[sizeof(hexd_buff)-1] = 0;
-	return hexd_buff;
+void udtrace_data(int fd, bool is_out, const char *fn, const uint8_t *data, unsigned int len)
+{
+	const struct sock_state *ss = udtrace_sstate_by_fd(fd);
+	if (!data || !len || !ss)
+		return;
+	ss->dissector(fd, is_out, fn, data, len);
 }
diff --git a/utils.h b/utils.h
index 8148518..f1f52f4 100644
--- a/utils.h
+++ b/utils.h
@@ -3,13 +3,19 @@
 /*! Determine number of elements in an array of static size */
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
+#define LOG(fmt, args ...) \
+	fprintf(stderr, ">>> UDTRACE: " fmt, ## args)
+
 /* add a file descriptor from the list of to-be-traced ones */
-void add_fd(int fd);
+void udtrace_add_fd(int fd);
 
 /* delete a file descriptor from the list of to-be-traced ones */
-void del_fd(int fd);
+void udtrace_del_fd(int fd);
+
+/* set the path of a given fd */
+void udtrace_fd_set_path(int fd, const char *path);
 
 /* is the given file descriptor part of the to-be-traced unix domain fd's? */
 bool is_unix_socket(int fd);
 
-char *udtrace_hexdump(const unsigned char *buf, int len, char *delim);
+void udtrace_data(int fd, bool is_out, const char *fn, const uint8_t *data, unsigned int len);