Added hooks to libdesock

libdesock/include/hooks.h

@@ -0,0 +1,9 @@
+#ifndef HOOKS_H
+#define HOOKS_H
+
+#include <stdlib.h>
+
+ssize_t hook_input (char*, size_t);
+ssize_t hook_output (char*, size_t);
+
+#endif

libdesock/src/accept.c

@@ -7,8 +7,8 @@
 #include <string.h>
 #include <netinet/in.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 static int internal_accept (int fd, struct sockaddr* restrict addr, socklen_t * restrict len, int flag) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/bind.c

@@ -4,8 +4,8 @@
 #define _GNU_SOURCE
 #include <unistd.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 visible int bind (int fd, const struct sockaddr* addr, socklen_t len) {
     if (VALID_FD (fd) && DESOCK_FD (fd)) {

libdesock/src/close.c

@@ -3,8 +3,8 @@
 #include <errno.h>
 #include <semaphore.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 visible int close (int fd) {
     int r = 0;

libdesock/src/connect.c

@@ -3,8 +3,8 @@
 #include <unistd.h>
 #include <sys/socket.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 visible int connect (int fd, const struct sockaddr* addr, socklen_t len) {
     if (VALID_FD (fd) && DESOCK_FD (fd)) {

libdesock/src/desock.c

@@ -9,8 +9,8 @@
 #include <netinet/in.h>
 #include <sys/un.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 const struct sockaddr_in stub_sockaddr_in = {
     .sin_family = AF_INET,
@@ -26,6 +26,9 @@ const struct sockaddr_in6 stub_sockaddr_in6 = {
     .sin6_scope_id = 0
 };
 
+/* Given an fd that is being desocketed fill the given sockaddress structure
+   with the right sockaddr stub from above.
+ */
 void fill_sockaddr (int fd, struct sockaddr* addr, socklen_t * addr_len) {
     if (addr && addr_len) {
         switch (fd_table[fd].domain) {
@@ -71,9 +74,18 @@ void _error (char* fmt_string, ...) {
     abort ();
 }
 
+/* Highest file descriptor number seen so far */
 int max_fd = 0;
+
+/* Indicates whether the next call to accept() should block or not */
 int accept_block = 1;
+
+/* Table that holds metadata about desocketed file descriptors */
 struct fd_entry fd_table[FD_TABLE_SIZE];
+
+/* Semaphore for synchronization of the connection pool in multi-threaded
+   applications.
+ */
 sem_t sem;
 
 __attribute__ ((constructor))

libdesock/src/dup.c

@@ -2,8 +2,8 @@
 #include <unistd.h>
 #include <string.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 visible int dup (int fd) {
     int ret = syscall (SYS_dup, fd);

libdesock/src/epoll.c

@@ -6,8 +6,8 @@
 #include <semaphore.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 #ifdef DEBUG
 visible int epoll_create (int size) {

libdesock/src/getpeername.c

@@ -4,8 +4,8 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 visible int getpeername (int fd, struct sockaddr* restrict addr, socklen_t * restrict len) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/getsockname.c

@@ -3,8 +3,8 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 visible int getsockname (int fd, struct sockaddr* restrict addr, socklen_t * restrict len) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/hooks.c

@@ -0,0 +1,31 @@
+/* The default action for libdesock is to
+ * read from stdin / write to stdout
+ * but this behaviour can be changed with the
+ * following to functions.
+ * They have to behave like glibc functions:
+ * On success they must return a value >= 0 indicating
+ * how many bytes have been read / written.
+ * On failure they must return -1 with errno set to the
+ * corresponding error.
+ */
+
+#include "hooks.h"
+#include "syscall.h"
+
+/* This function is called whenever a read on a network
+ * connection occurs. Read from stdin instead.
+ */
+ssize_t hook_input (char* buf, size_t size) {
+    return syscall_cp(SYS_read, 0, buf, size);
+}
+
+/* This function is called whenever a write on a network
+ * connection occurs. Write to stdout instead.
+ */
+ssize_t hook_output (char* buf, size_t size) {
+#ifdef DEBUG
+    return syscall_cp(SYS_write, 1, buf, size);
+#else
+    return (ssize_t) size;
+#endif
+}

libdesock/src/listen.c

@@ -2,8 +2,8 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 visible int listen (int fd, int backlog) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/peekbuffer.c

@@ -4,9 +4,9 @@
 #include <errno.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
-#include <peekbuffer.h>
+#include "desock.h"
+#include "syscall.h"
+#include "peekbuffer.h"
 
 char static_buffer[STATIC_BUFFER_SIZE];
 

libdesock/src/poll.c

@@ -4,8 +4,8 @@
 #include <signal.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 static int internal_poll (struct pollfd* fds, nfds_t n) {
     DEBUG_LOG ("[%d] desock::internal_poll(%p, %d)", gettid (), fds, n);

libdesock/src/read.c

@@ -6,9 +6,10 @@
 #include <string.h>
 #include <errno.h>
 
-#include <syscall.h>
-#include <desock.h>
-#include <peekbuffer.h>
+#include "syscall.h"
+#include "desock.h"
+#include "peekbuffer.h"
+#include "hooks.h"
 
 static long internal_readv (struct iovec* iov, int len, int* full, int peek, int offset) {
     int read_in = 0;
@@ -30,7 +31,7 @@ static long internal_readv (struct iovec* iov, int len, int* full, int peek, int
 
             if (r < iov[i].iov_len) {
                 errno = 0;
-                r += syscall_cp (SYS_read, 0, (char *) iov[i].iov_base + r, iov[i].iov_len - r);
+                r += hook_input((char *) iov[i].iov_base + r, iov[i].iov_len - r);
 
                 if (errno) {
                     return -1;
@@ -64,7 +65,7 @@ visible ssize_t read (int fd, void* buf, size_t count) {
 
         if (offset < count) {
             errno = 0;
-            offset += syscall_cp (SYS_read, 0, (char *) buf + offset, count - offset);
+            offset += hook_input((char *) buf + offset, count - offset);
 
             if (errno) {
                 DEBUG_LOG (" = -1\n");
@@ -97,7 +98,7 @@ static ssize_t internal_recv (int fd, char* buf, size_t len, int flags) {
 
     if (offset < len) {
         errno = 0;
-        offset += (syscall_cp (SYS_read, 0, buf + offset, len - offset));
+        offset += hook_input(buf + offset, len - offset);
 
         if (errno) {
             return -1;

libdesock/src/select.c

@@ -6,8 +6,8 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 static int internal_select (int n, fd_set * rfds, fd_set * wfds, fd_set * efds) {
     DEBUG_LOG ("[%d] desock::internal_select(%d, %p, %p, %p)", gettid (), n, rfds, wfds, efds);

libdesock/src/sendfile.c

@@ -2,9 +2,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
-#include <musl-features.h>
+#include "desock.h"
+#include "syscall.h"
+#include "musl-features.h"
 
 visible ssize_t sendfile (int out_fd, int in_fd, off_t * ofs, size_t count) {
     if (VALID_FD (out_fd) && fd_table[out_fd].desock) {

libdesock/src/shutdown.c

@@ -3,8 +3,8 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 visible int shutdown (int fd, int how) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/socket.c

@@ -5,8 +5,8 @@
 #include <unistd.h>
 #include <string.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
 
 visible int socket (int domain, int type, int protocol) {
     DEBUG_LOG ("[%d] desock::socket(%d, %d, %d)", gettid (), domain, type, protocol);

libdesock/src/sockopt.c

@@ -3,8 +3,8 @@
 #include <string.h>
 #include <unistd.h>
 
-#include <desock.h>
-#include <syscall.h>
+#include "desock.h"
+#include "syscall.h"
 
 visible int setsockopt (int fd, int level, int optname, const void* optval, socklen_t optlen) {
     if (VALID_FD (fd) && fd_table[fd].desock) {

libdesock/src/syscall.c

@@ -1,5 +1,5 @@
 
-#include <syscall.h>
+#include "syscall.h"
 
 hidden long __syscall_cp_c ();
 

libdesock/src/write.c

@@ -4,18 +4,18 @@
 #include <errno.h>
 #include <sys/socket.h>
 
-#include <syscall.h>
-#include <desock.h>
+#include "syscall.h"
+#include "desock.h"
+#include "hooks.h"
 
 static long internal_writev (const struct iovec* iov, int len) {
     int written = 0;
 
     for (int i = 0; i < len; ++i) {
-#ifdef DEBUG
         int offset = 0, r;
 
         do {
-            r = syscall_cp (SYS_write, 1, (char *) iov[i].iov_base + offset, iov[i].iov_len - offset);
+            r = hook_output((char *) iov[i].iov_base + offset, iov[i].iov_len - offset);
 
             if (r == -1) {
                 return -1;
@@ -24,51 +24,36 @@ static long internal_writev (const struct iovec* iov, int len) {
             written += r;
             offset += r;
         } while (offset < iov[i].iov_len && r > 0);
-#else
-        written += iov[i].iov_len;
-#endif
     }
 
     return written;
 }
 
 visible ssize_t write (int fd, const void* buf, size_t count) {
     if (VALID_FD (fd) && fd_table[fd].desock) {
-#ifdef DEBUG
-        int r = syscall_cp (SYS_write, 1, buf, count);
+        int r = hook_output(buf, count);
         DEBUG_LOG ("[%d] desock::write(%d, %p, %lu) = %d\n", gettid (), fd, buf, count, r);
         return r;
-#else
-        return count;
-#endif
     } else {
         return syscall_cp (SYS_write, fd, buf, count);
     }
 }
 
 visible ssize_t send (int fd, const void* buf, size_t len, int flags) {
     if (VALID_FD (fd) && fd_table[fd].desock) {
-#ifdef DEBUG
-        int r = syscall_cp (SYS_write, 1, buf, len);
+        int r = hook_output(buf, len);
         DEBUG_LOG ("[%d] desock::send(%d, %p, %lu, %d) = %d\n", gettid (), fd, buf, len, flags, r);
         return r;
-#else
-        return len;
-#endif
     } else {
         return sendto (fd, buf, len, flags, 0, 0);
     }
 }
 
 visible ssize_t sendto (int fd, const void* buf, size_t len, int flags, const struct sockaddr* addr, socklen_t alen) {
     if (VALID_FD (fd) && fd_table[fd].desock) {
-#ifdef DEBUG
-        int r = syscall_cp (SYS_write, 1, buf, len);
+        int r = hook_output(buf, len);
         DEBUG_LOG ("[%d] desock::sendto(%d, %p, %lu, %d, %p, %lu) = %d\n", gettid (), fd, buf, len, flags, addr, alen, r);
         return r;
-#else
-        return len;
-#endif
     } else {
         return socketcall_cp (sendto, fd, buf, len, flags, addr, alen);
     }