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-rw-r--r--src/peekfd.c466
1 files changed, 466 insertions, 0 deletions
diff --git a/src/peekfd.c b/src/peekfd.c
new file mode 100644
index 0000000..36dff04
--- /dev/null
+++ b/src/peekfd.c
@@ -0,0 +1,466 @@
+/*
+ * peekfd.c - Intercept file descriptor read and writes
+ *
+ * Copyright (C) 2007 Trent Waddington <trent.waddington@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/syscall.h>
+#include <asm/ptrace.h>
+#include <byteswap.h>
+#include <endian.h>
+#include <sys/user.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <stdint.h>
+#include <errno.h>
+#include <string.h>
+
+#include "i18n.h"
+
+#ifdef ARM64
+#include <sys/uio.h>
+#include <linux/elf.h>
+#endif
+
+#ifdef I386
+ #define REG_ORIG_ACCUM orig_eax
+ #define REG_ACCUM eax
+ #define REG_PARAM1 ebx
+ #define REG_PARAM2 ecx
+ #define REG_PARAM3 edx
+#elif X86_64
+ #define REG_ORIG_ACCUM orig_rax
+ #define REG_ACCUM rax
+ #define REG_PARAM1 rdi
+ #define REG_PARAM2 rsi
+ #define REG_PARAM3 rdx
+#elif PPC
+ #if !defined(__WORDSIZE)
+ #include <bits/reg.h>
+ #endif
+
+ #define REG_ORIG_ACCUM gpr[0]
+ #define REG_ACCUM gpr[3]
+ #define REG_PARAM1 orig_gpr3
+ #define REG_PARAM2 gpr[4]
+ #define REG_PARAM3 gpr[5]
+#ifndef PT_ORIG_R3
+ #define PT_ORIG_R3 34
+#endif
+#elif defined(ARM)
+#ifndef __ARM_EABI__
+#error arm oabi not supported
+#endif
+ #define REG_ORIG_ACCUM ARM_r7
+ #define REG_ACCUM ARM_r0
+ #define REG_PARAM1 ARM_ORIG_r0
+ #define REG_PARAM2 ARM_r1
+ #define REG_PARAM3 ARM_r2
+
+#elif defined(ARM64)
+ #define REG_ORIG_ACCUM regs[8]
+ #define REG_ACCUM regs[0]
+ #define REG_PARAM1 regs[0]
+ #define REG_PARAM2 regs[1]
+ #define REG_PARAM3 regs[2]
+
+
+
+#elif defined(MIPS)
+#ifndef MIPSEL
+#error only little endian supported
+#endif
+ #define REG_ORIG_ACCUM regs[3]
+ #define REG_ACCUM regs[2]
+ #define REG_PARAM1 regs[4]
+ #define REG_PARAM2 regs[5]
+ #define REG_PARAM3 regs[6]
+#elif defined(M68K)
+ #define REG_ORIG_ACCUM orig_d0
+ #define REG_ACCUM d0
+ #define REG_PARAM1 d1
+ #define REG_PARAM2 d2
+ #define REG_PARAM3 d3
+#endif
+
+#define MAX_ATTACHED_PIDS 1024
+int num_attached_pids = 0;
+pid_t attached_pids[MAX_ATTACHED_PIDS];
+int *fds = NULL;
+
+#ifdef ARM64
+struct user_pt_regs_node {
+ struct user_pt_regs regs;
+ struct user_pt_regs_node *user_pt_regs_next;
+};
+
+void user_pt_regs_insert(struct user_pt_regs_node** user_pt_regs_head, struct user_pt_regs *regs)
+{
+ struct user_pt_regs_node* new_node =
+ (struct user_pt_regs_node*) malloc(sizeof(struct user_pt_regs_node));
+
+ memcpy(&new_node->regs, regs, sizeof(struct user_pt_regs));
+ new_node->user_pt_regs_next = (*user_pt_regs_head);
+ (*user_pt_regs_head) = new_node;
+}
+
+struct user_pt_regs * user_pt_regs_search(struct user_pt_regs_node** user_pt_regs_head, struct user_pt_regs *regs)
+{
+ struct user_pt_regs_node* current = *user_pt_regs_head;
+ while (current != NULL)
+ {
+ if ((current->regs.REG_ORIG_ACCUM == regs->REG_ORIG_ACCUM) && (current->regs.REG_PARAM2 == regs->REG_PARAM2))
+ return &current->regs;
+ current = current->user_pt_regs_next;
+ }
+ return NULL;
+}
+
+
+int user_pt_regs_delete(struct user_pt_regs_node** user_pt_regs_head, struct user_pt_regs *regs)
+{
+ struct user_pt_regs_node* temp = *user_pt_regs_head, *prev;
+
+ if (temp != NULL && (&temp->regs == regs))
+ {
+ *user_pt_regs_head = temp->user_pt_regs_next;
+ free(temp);
+ return 0;
+ }
+
+ while (temp != NULL && (&temp->regs != regs))
+ {
+ prev = temp;
+ temp = temp->user_pt_regs_next;
+ }
+
+ if (temp == NULL) return -1;
+ prev->user_pt_regs_next = temp->user_pt_regs_next;
+ free(temp);
+ return 0;
+}
+#endif
+
+void detach(int signum) {
+ int i;
+ for (i = 0; i < num_attached_pids; i++)
+ ptrace(PTRACE_DETACH, attached_pids[i], 0, 0);
+ if (fds)
+ free(fds);
+ signal(SIGINT, SIG_DFL);
+ raise(SIGINT);
+}
+
+void attach(pid_t pid) {
+ if (num_attached_pids >= MAX_ATTACHED_PIDS)
+ return;
+ attached_pids[num_attached_pids] = pid;
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+ fprintf(stderr, _("Error attaching to pid %i\n"), pid);
+ return;
+ }
+ num_attached_pids++;
+}
+
+void print_version()
+{
+ fprintf(stderr, _("peekfd (PSmisc) %s\n"), VERSION);
+ fprintf(stderr, _(
+ "Copyright (C) 2007 Trent Waddington\n\n"));
+ fprintf(stderr, _(
+ "PSmisc comes with ABSOLUTELY NO WARRANTY.\n"
+ "This is free software, and you are welcome to redistribute it under\n"
+ "the terms of the GNU General Public License.\n"
+ "For more information about these matters, see the files named COPYING.\n"));
+}
+
+void usage() {
+ fprintf(stderr, _(
+ "Usage: peekfd [-8] [-n] [-c] [-d] [-V] [-h] <pid> [<fd> ..]\n"
+ " -8, --eight-bit-clean output 8 bit clean streams.\n"
+ " -n, --no-headers don't display read/write from fd headers.\n"
+ " -c, --follow peek at any new child processes too.\n"
+ " -t, --tgid peek at all threads where tgid equals <pid>.\n"
+ " -d, --duplicates-removed remove duplicate read/writes from the output.\n"
+ " -V, --version prints version info.\n"
+ " -h, --help prints this help.\n"
+ "\n"
+ " Press CTRL-C to end output.\n"));
+}
+
+int bufdiff(pid_t pid, unsigned char *lastbuf, unsigned long addr, unsigned long len) {
+ unsigned long i;
+ for (i = 0; i < len; i++)
+ if (lastbuf[i] != (ptrace(PTRACE_PEEKTEXT, pid, addr + i, 0) & 0xff))
+ return 1;
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int eight_bit_clean = 0;
+ int no_headers = 0;
+ int follow_forks = 0;
+ int follow_clones = 0;
+ int tgid = 0;
+ int remove_duplicates = 0;
+ int optc;
+ int target_pid = 0;
+ int numfds = 0;
+ int i;
+ unsigned long j;
+
+ struct option options[] = {
+ {"eight-bit-clean", 0, NULL, '8'},
+ {"no-headers", 0, NULL, 'n'},
+ {"follow", 0, NULL, 'c'},
+ {"tgid", 0, NULL, 't'},
+ {"duplicates-removed", 0, NULL, 'd'},
+ {"help", 0, NULL, 'h'},
+ {"version", 0, NULL, 'V'},
+ };
+
+ /* Setup the i18n */
+#ifdef ENABLE_NLS
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+#endif
+
+ if (argc < 2) {
+ usage();
+ return 1;
+ }
+
+ while ((optc = getopt_long(argc, argv, "8nctdhV", options, NULL)) != -1) {
+ switch(optc) {
+ case '8':
+ eight_bit_clean = 1;
+ break;
+ case 'n':
+ no_headers = 1;
+ break;
+ case 'c':
+ follow_forks = 1;
+ follow_clones = 1;
+ break;
+ case 't':
+ tgid = 1;
+ follow_clones = 1;
+ break;
+ case 'd':
+ remove_duplicates = 1;
+ break;
+ case 'V':
+ print_version();
+ return 1;
+ case 'h':
+ case '?':
+ usage();
+ return 1;
+ }
+ }
+ /* First arg off the options is the PID to see */
+ if (optind >= argc) {
+ usage();
+ return -1;
+ }
+ target_pid = atoi(argv[optind++]);
+
+ if (optind < argc) {
+ numfds = argc - optind;
+ fds = malloc(sizeof(int) * numfds);
+ for (i = 0; i < numfds; i++)
+ fds[i] = atoi(argv[optind + i]);
+ }
+
+ attach(target_pid);
+
+ if (tgid) {
+ DIR *taskdir;
+ struct dirent *dt;
+ char taskpath[24];
+
+ snprintf(taskpath, 24, "/proc/%d/task", target_pid);
+
+ if ((taskdir = opendir(taskpath)) != 0) {
+ while ((dt = readdir(taskdir)) != NULL) {
+ int thread = atoi(dt->d_name);
+ if ((thread != 0) && (thread != target_pid))
+ attach(thread);
+ }
+ closedir(taskdir);
+ }
+ }
+
+ if (num_attached_pids == 0)
+ return 1;
+
+ signal(SIGINT, detach);
+
+ for (i = 0; i < num_attached_pids; i++)
+ ptrace(PTRACE_SYSCALL, attached_pids[i], 0, 0);
+
+ /*int count = 0;*/
+ int lastfd = numfds > 0 ? fds[0] : 0;
+ int lastdir = 3;
+ unsigned char *lastbuf = NULL;
+ unsigned long last_buf_size = -1;
+
+#ifdef ARM64
+ struct user_pt_regs_node* user_pt_regs_head = NULL;
+#endif
+
+ for(;;) {
+ int status;
+ pid_t pid = wait(&status);
+ if (WIFSTOPPED(status)) {
+#ifdef PPC
+ struct pt_regs regs;
+ regs.gpr[0] = ptrace(PTRACE_PEEKUSER, pid, __WORDSIZE/8 * PT_R0, 0);
+ regs.gpr[3] = ptrace(PTRACE_PEEKUSER, pid, __WORDSIZE/8 * PT_R3, 0);
+ regs.gpr[4] = ptrace(PTRACE_PEEKUSER, pid, __WORDSIZE/8 * PT_R4, 0);
+ regs.gpr[5] = ptrace(PTRACE_PEEKUSER, pid, __WORDSIZE/8 * PT_R5, 0);
+ regs.orig_gpr3 = ptrace(PTRACE_PEEKUSER, pid, __WORDSIZE/8 * PT_ORIG_R3, 0);
+#elif defined(ARM)
+ struct pt_regs regs;
+ ptrace(PTRACE_GETREGS, pid, 0, &regs);
+
+#elif defined(ARM64)
+ struct user_pt_regs regs, *old_regs;
+ struct iovec io;
+ io.iov_base = &regs;
+ io.iov_len = sizeof(regs);
+
+ if (ptrace(PTRACE_GETREGSET, pid, (void*) NT_PRSTATUS, (void*) &io) == -1) {
+ printf("ARM64: PTRACE_GETREGSET: %s\n", strerror(errno));
+ return errno;
+ }
+
+#elif defined(MIPS)
+ struct pt_regs regs;
+ long pc = ptrace(PTRACE_PEEKUSER, pid, 64, 0);
+ regs.regs[2] = ptrace(PTRACE_PEEKUSER,pid,2,0);
+ regs.regs[3] = ptrace(PTRACE_PEEKTEXT, pid, pc - 8, 0) & 0xffff;
+ regs.regs[4] = ptrace(PTRACE_PEEKUSER,pid,4,0);
+ regs.regs[5] = ptrace(PTRACE_PEEKUSER,pid,5,0);
+ regs.regs[6] = ptrace(PTRACE_PEEKUSER,pid,6,0);
+#else
+ struct user_regs_struct regs;
+ ptrace(PTRACE_GETREGS, pid, 0, &regs);
+#endif
+ /*unsigned int b = ptrace(PTRACE_PEEKTEXT, pid, regs.eip, 0);*/
+
+#if defined(ARM64)
+ if (follow_forks && regs.REG_ORIG_ACCUM == SYS_clone) {
+#else
+ if ((follow_forks && regs.REG_ORIG_ACCUM == SYS_fork)
+ || (follow_clones && regs.REG_ORIG_ACCUM == SYS_clone)) {
+#endif
+ if (regs.REG_ACCUM > 0)
+ attach(regs.REG_ACCUM);
+ }
+ if ((regs.REG_ORIG_ACCUM == SYS_read || regs.REG_ORIG_ACCUM == SYS_write) && (regs.REG_PARAM3 == regs.REG_ACCUM)) {
+#ifdef ARM64
+ /* ARM64 doesn't expose orig_x0 to user space,
+ so retrive orig_x0 from older user pt regs */
+ old_regs = user_pt_regs_search(&user_pt_regs_head, &regs);
+ if (old_regs != NULL) {
+ regs.REG_PARAM1 = old_regs->REG_PARAM1;
+ user_pt_regs_delete(&user_pt_regs_head, old_regs);
+ }
+#endif
+ for (i = 0; i < numfds; i++)
+ if (fds[i] == (int)regs.REG_PARAM1)
+ break;
+ if (i != numfds || numfds == 0) {
+ if ((int)regs.REG_PARAM1 != lastfd || (int)regs.REG_ORIG_ACCUM != lastdir) {
+ lastfd = regs.REG_PARAM1;
+ lastdir = regs.REG_ORIG_ACCUM;
+ if (!no_headers) {
+ printf("\n%sing fd %i", regs.REG_ORIG_ACCUM == SYS_read ? "read" : "writ", lastfd);
+ if (tgid)
+ printf(" (thread %d)", pid);
+ printf(":\n");
+ }
+ }
+ if (!remove_duplicates || lastbuf == NULL
+ || last_buf_size != regs.REG_PARAM3 ||
+ bufdiff(pid, lastbuf, regs.REG_PARAM2, regs.REG_PARAM3)) {
+
+ if (remove_duplicates) {
+ if (lastbuf)
+ free(lastbuf);
+ if ( NULL == (lastbuf = malloc(regs.REG_PARAM3))) {
+ perror("lastbuf malloc");
+ exit(1);
+ }
+ last_buf_size = regs.REG_PARAM3;
+ }
+
+ for (j = 0; j < regs.REG_PARAM3; j++) {
+#if BYTE_ORDER == BIG_ENDIAN
+#if __WORDSIZE == 64
+ unsigned int a = bswap_64(ptrace(PTRACE_PEEKTEXT, pid, regs.REG_PARAM2 + j, 0));
+#else
+ unsigned int a = bswap_32(ptrace(PTRACE_PEEKTEXT, pid, regs.REG_PARAM2 + j, 0));
+#endif
+#else
+ unsigned int a = ptrace(PTRACE_PEEKTEXT, pid, regs.REG_PARAM2 + j, 0);
+#endif
+ if (remove_duplicates)
+ lastbuf[j] = a & 0xff;
+
+ if (eight_bit_clean)
+ putchar(a & 0xff);
+ else {
+ if (isprint(a & 0xff) || (a & 0xff) == '\n')
+ printf("%c", a & 0xff);
+ else if ((a & 0xff) == 0x0d)
+ printf("\n");
+ else if ((a & 0xff) == 0x7f)
+ printf("\b");
+ else if (a & 0xff)
+ printf(" [%02x] ", a & 0xff);
+ }
+ }
+ }
+ fflush(stdout);
+ }
+ }
+#ifdef ARM64
+ else if (regs.REG_ORIG_ACCUM == SYS_read || regs.REG_ORIG_ACCUM == SYS_write)
+ {
+ user_pt_regs_insert(&user_pt_regs_head,&regs);
+ }
+#endif
+ ptrace(PTRACE_SYSCALL, pid, 0, 0);
+ }
+ }
+
+ return 0;
+}
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