HXBC.us - 竹難月金

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> debug.c:
> 
>     #include <glib.h>
>     
>     #include <arpa/inet.h>
>     #include <stdio.h>
>     #include <string.h>
>     #include <sys/socket.h>
>     #include <sys/types.h>
>     
>     void ld_attach() __attribute((constructor));
>     static gboolean ld_read_cb(GIOChannel *source, GIOCondition cond,
>                                gpointer data);
>     static gboolean ld_conn_cb(GIOChannel *source, GIOCondition cond,
>                                gpointer data);
>     static int ld_create_socket();
>     
>     static guint source_id = -1;
>     
>     void
>     ld_attach()
>     {
>         int fd = ld_create_socket();
>     
>         if (fd == -1) {
>             return;
>         }
>     
>         GIOChannel *channel = g_io_channel_unix_new(fd);
>     
>         source_id = g_io_add_watch(channel, G_IO_IN | G_IO_HUP, ld_conn_cb, NULL);
>     }
>     
>     static gboolean
>     ld_conn_cb(GIOChannel *channel, GIOCondition cond, gpointer data)
>     {
>         struct sockaddr_in in_addr;
>         socklen_t size = -1;
>     
>         if (cond == G_IO_IN) {
>             int fd = g_io_channel_unix_get_fd(channel);
>             int new_fd = -1;
>     
>             size = sizeof(in_addr);
>             if ((new_fd = accept(fd, (struct sockaddr *)&in_addr, &size)) == -1) {
>                 perror("accept");
>                 return TRUE;
>             }
>     
>             GIOChannel *channel2 = g_io_channel_unix_new(new_fd);
>             source_id = g_io_add_watch(channel2, G_IO_IN | G_IO_HUP, ld_read_cb,
>                                        NULL);
>         }
>     
>         return TRUE;
>     }
>     
>     static gboolean
>     ld_read_cb(GIOChannel *channel, GIOCondition cond, gpointer data)
>     {
>         int addr = 0;
>         char *line = NULL;
>     
>         if (cond == G_IO_IN) {
>             while (g_io_channel_read_line(channel, &line, NULL, NULL, NULL) == 
>                    G_IO_STATUS_NORMAL) {
>                 if (sscanf(line, "%x\n", &addr) == 1) {
>                     char *ptr = GINT_TO_POINTER(addr);
>                     int i = 0;
>     
>                     printf("Reading address %p: ", ptr);
>     
>                     for (i = 0; i < 10 && *ptr; i++, ptr++) {
>                         printf("%c", *ptr);
>                     }
>     
>                     printf("\n");
>                 }
>             }
>         } else if (cond == G_IO_ERR || cond == G_IO_HUP) {
>             g_io_channel_shutdown(channel, FALSE, NULL);
>         }
>     
>         return TRUE;
>     }
>     
>     static int
>     ld_create_socket()
>     {
>         int fd = -1;
>         struct sockaddr_in addr;
>     
>         if ((fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
>             perror("socket");
>             return -1;
>         }
>     
>         memset(&addr, 0, sizeof(addr));
>         addr.sin_family = AF_INET;
>         addr.sin_addr.s_addr = INADDR_ANY;
>         addr.sin_port = htons(34567);
>     
>         if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
>             perror("bind");
>             return -1;
>         }
>     
>         if (listen(fd, 0) == -1) {
>             perror("listen");
>             return -1;
>         }
>     
>         return fd;
>     }
>     
> main.c:
> 
>     #include <stdio.h>
>     #include <glib.h>
>     
>     int
>     main(int argc, char **argv)
>     {
>         GMainLoop *mainloop = g_main_loop_new(NULL, FALSE);
>         printf("%p: %s\n", argv[0], argv[0]);
>     
>         g_main_loop_run(mainloop);
>     
>         return 0;
>     }
> 
> Makefile:
> 
>     LSRC=											\
>     	debug.c										\
>     
>     
>     SRC=											\
>     	main.c										\
>     
>     
>     LOBJ = $(LSRC:.c=.o)
>     
>     OBJ = $(SRC:.c=.o)
>     
>     CFLAGS += -Wall -g -Werror -Wextra -Wfloat-equal -Wbad-function-cast -Wcast-qual -Winline -Wno-unused-parameter
>     CFLAGS += `pkg-config --cflags glib-2.0` -I$(PWD)
>     LFLAGS += `pkg-config --libs glib-2.0`
>     
>     LIBOUT = libdebug.so
>     
>     OUT = test
>     
>     all: $(LIBOUT) $(OUT)
>     
>     $(OUT): $(OBJ)
>     	$(CC) $(CFLAGS) $(LFLAGS) $(OBJ) -L$(PWD) -o $(OUT)
>     
>     $(LIBOUT): $(LOBJ)
>     	$(CC) -shared -Wl,-soname,$(LIBOUT) $(CFLAGS) $(LFLAGS) $(LOBJ) -o $(LIBOUT)
>     
>     $(OBJ): %.o: %.c
>     	$(CC) $(CFLAGS) -c $< -o $@
>     
>     $(LOBJ): %.o: %.c
>     	$(CC) -fPIC $(CFLAGS) -c $< -o $@
>     
>     clean:
>     	$(RM) $(LOBJ) $(LIBOUT) $(OUT) $(OBJ)
> 
> To run:
> 
>     $ make
>     $ LD_PRELOAD=./libdebug.so ./test
>     0xbfc5b9b7: ./test
> 
> Then in another terminal:
> 
>     $ telnet 127.0.0.1 34567
>     Trying 127.0.0.1...
>     Connected to 127.0.0.1.
>     Escape character is '^]'.
>     0xbfc5b9b7
> 
> You should see this printed out in the original terminal:
> 
>     $ LD_PRELOAD=./libdebug.so ./test
>     0xbfc5b9b7: ./test
>     Reading address 0xbfc5b9b7: ./test
> 
> Printing the result in the telnet window is left as an exercise for the reader.