diff options
| -rw-r--r-- | lib/intercept/intercept.cpp | 175 | ||||
| -rw-r--r-- | lib/intercept/intercept.h | 42 |
2 files changed, 217 insertions, 0 deletions
diff --git a/lib/intercept/intercept.cpp b/lib/intercept/intercept.cpp index 21220cc9..a4dfcc37 100644 --- a/lib/intercept/intercept.cpp +++ b/lib/intercept/intercept.cpp @@ -9,6 +9,8 @@ #include "Box.h" +#include "intercept.h" + #ifdef HAVE_SYS_SYSCALL_H #include <sys/syscall.h> #endif @@ -21,6 +23,10 @@ #include <errno.h> +#ifdef HAVE_DLFCN_H +#include <dlfcn.h> +#endif + #ifndef PLATFORM_CLIB_FNS_INTERCEPTION_IMPOSSIBLE #if !defined(HAVE_SYSCALL) && !defined(HAVE___SYSCALL) && !defined(HAVE___SYSCALL_NEED_DEFN) @@ -317,4 +323,173 @@ lseek(int fildes, off_t offset, int whence) return r; } +static opendir_t* opendir_real = NULL; +static readdir_t* readdir_real = NULL; +static readdir_t* readdir_hook = NULL; +static closedir_t* closedir_real = NULL; +static lstat_t* lstat_real = NULL; +static lstat_t* lstat_hook = NULL; +static const char* lstat_file = NULL; + +void intercept_setup_readdir_hook(const char *dirname, readdir_t hookfn) +{ + if (hookfn != NULL && dirname == NULL) + { + dirname = intercept_filename; + } + + if (hookfn != NULL) + { + TRACE2("readdir hooked to %p for %s\n", hookfn, dirname); + } + else + { + TRACE2("readdir unhooked from %p for %s\n", readdir_hook, + intercept_filename); + } + + intercept_filename = dirname; + readdir_hook = hookfn; +} + +void intercept_setup_lstat_hook(const char *filename, lstat_t hookfn) +{ + /* + if (hookfn != NULL) + { + TRACE2("lstat hooked to %p for %s\n", hookfn, filename); + } + else + { + TRACE2("lstat unhooked from %p for %s\n", lstat_hook, + lstat_file); + } + */ + + lstat_file = filename; + lstat_hook = hookfn; +} + +extern "C" +DIR *opendir(const char *dirname) +{ + if (opendir_real == NULL) + { + opendir_real = (opendir_t*)(dlsym(RTLD_NEXT, "opendir")); + } + + if (opendir_real == NULL) + { + perror("cannot find real opendir"); + return NULL; + } + + DIR* r = opendir_real(dirname); + + if(readdir_hook != NULL && intercept_filedes == -1 && + strcmp(intercept_filename, dirname) == 0) + { + intercept_filedes = dirfd(r); + //printf("Found file to intercept, h = %d\n", r); + } + + return r; +} + +extern "C" +struct dirent *readdir(DIR *dir) +{ + if (readdir_hook != NULL && dirfd(dir) == intercept_filedes) + { + return readdir_hook(dir); + } + + if (readdir_real == NULL) + { + #if readdir == readdir64 + readdir_real = (readdir_t*)(dlsym(RTLD_NEXT, "readdir64")); + #else + readdir_real = (readdir_t*)(dlsym(RTLD_NEXT, "readdir")); + #endif + } + + if (readdir_real == NULL) + { + perror("cannot find real readdir"); + return NULL; + } + + return readdir_real(dir); +} + +extern "C" +int closedir(DIR *dir) +{ + if (dirfd(dir) == intercept_filedes) + { + intercept_filedes = -1; + } + + if (closedir_real == NULL) + { + closedir_real = (closedir_t*)(dlsym(RTLD_NEXT, "closedir")); + } + + if (closedir_real == NULL) + { + perror("cannot find real closedir"); + errno = ENOSYS; + return -1; + } + + return closedir_real(dir); +} + +extern "C" int +#ifdef LINUX_WEIRD_LSTAT +__lxstat(int ver, const char *file_name, STAT_STRUCT *buf) +#else +lstat(const char *file_name, STAT_STRUCT *buf) +#endif +{ + if (lstat_real == NULL) + { + #ifdef LINUX_WEIRD_LSTAT + #if __lxstat == __lxstat64 + lstat_real = (lstat_t*)(dlsym(RTLD_NEXT, "__lxstat64")); + #else + lstat_real = (lstat_t*)(dlsym(RTLD_NEXT, "__lxstat")); + #endif + #else + #if lstat == lstat64 + lstat_real = (lstat_t*)(dlsym(RTLD_NEXT, "lstat64")); + #else + lstat_real = (lstat_t*)(dlsym(RTLD_NEXT, "lstat")); + #endif + #endif + } + + if (lstat_real == NULL) + { + perror("cannot find real lstat"); + errno = ENOSYS; + return -1; + } + + if (lstat_hook == NULL || strcmp(file_name, lstat_file) != 0) + { + #ifdef LINUX_WEIRD_LSTAT + return lstat_real(ver, file_name, buf); + #else + return lstat_real(file_name, buf); + #endif + } + + #ifdef LINUX_WEIRD_LSTAT + return lstat_hook(ver, file_name, buf); + #else + return lstat_hook(file_name, buf); + #endif +} + #endif // n PLATFORM_CLIB_FNS_INTERCEPTION_IMPOSSIBLE diff --git a/lib/intercept/intercept.h b/lib/intercept/intercept.h new file mode 100644 index 00000000..b1122434 --- /dev/null +++ b/lib/intercept/intercept.h @@ -0,0 +1,42 @@ +// -------------------------------------------------------------------------- +// +// File +// Name: intercept.h +// Purpose: Syscall interception code for unit tests +// Created: 2006/11/29 +// +// -------------------------------------------------------------------------- + +#ifndef INTERCEPT_H +#define INTERCEPT_H + +#include <dirent.h> + +#include <sys/types.h> +#include <sys/stat.h> + +extern "C" +{ + typedef DIR *(opendir_t) (const char *name); + typedef struct dirent *(readdir_t) (DIR *dir); + typedef struct dirent *(readdir_t) (DIR *dir); + typedef int (closedir_t)(DIR *dir); +#if defined __GNUC__ && __GNUC__ >= 2 +#define LINUX_WEIRD_LSTAT +#define STAT_STRUCT struct stat /* should be stat64 */ + typedef int (lstat_t) (int ver, const char *file_name, + STAT_STRUCT *buf); +#else +#define STAT_STRUCT struct stat + typedef int (lstat_t) (const char *file_name, + STAT_STRUCT *buf); +#endif +} + +void intercept_setup_error(const char *filename, unsigned int errorafter, + int errortoreturn, int syscalltoerror); + +void intercept_setup_readdir_hook(const char *dirname, readdir_t hookfn); +void intercept_setup_lstat_hook (const char *filename, lstat_t hookfn); + +#endif // !INTERCEPT_H |