ios: Migrate //ios/third_party/fishhook from a DEP to a local fork.

fishhook is a small and rarely updated dependency. To easy the rapid
updates needed roughly once a year, move this to a local fork.

Bug: 1217674
Change-Id: I90bacf6d3eb8d64ee4cd9e5268f73fd82a5d68c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2949849
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#892254}

.gitignore

@@ -218,7 +218,6 @@ vs-chromium-project.txt
 /ios/third_party/earl_grey/src
 /ios/third_party/earl_grey2/src
 /ios/third_party/edo/src
-/ios/third_party/fishhook/src
 /ios/third_party/gcdwebserver/src
 /ios/third_party/gtx/src
 /ios/third_party/material_components_ios/src

DEPS

@@ -570,11 +570,6 @@ deps = {
       'condition': 'checkout_ios',
   },
 
-  'src/ios/third_party/fishhook/src': {
-      'url': Var('chromium_git') + '/external/github.com/facebook/fishhook.git' + '@' + '66315a9c251edfe92f669ae2deeac0d75374c948',
-      'condition': 'checkout_ios',
-  },
-
   'src/ios/third_party/gcdwebserver/src': {
       'url': Var('chromium_git') + '/external/github.com/swisspol/GCDWebServer.git' + '@' + '43555c66627f6ed44817855a0f6d465f559d30e0',
       'condition': 'checkout_ios',

ios/third_party/fishhook/BUILD.gn

@@ -3,15 +3,15 @@
 # found in the LICENSE file.
 
 config("fishhook_config") {
-  include_dirs = [ "src" ]
+  include_dirs = [ "." ]
   visibility = [ ":fishhook" ]
 }
 
 source_set("fishhook") {
   testonly = true
   sources = [
-    "src/fishhook.c",
-    "src/fishhook.h",
+    "fishhook.c",
+    "fishhook.h",
   ]
 
   public_configs = [ ":fishhook_config" ]

ios/third_party/fishhook/README.chromium

@@ -2,6 +2,7 @@ Name: fishhook
 Short Name: fishhook
 URL: https://github.com/facebook/fishhook
 Version: 0.2
+Revision: 8ef82f0711494ecc78d16bf6ce76f5ad92e5f67b
 License: BSD
 License File: NOT_SHIPPED
 Security Critical: no
@@ -9,3 +10,7 @@ Security Critical: no
 Description:
 Fishhook is a library that enables dynamically rebinding symbols in Mach-O
 binaries running on iOS.
+
+Local Modifications:
+2021.06.09: https://github.com/facebook/fishhook/pull/84/files:  If hooking in
+__DATA_CONST or __AUTH_CONST, promise writable before trying to write.

ios/third_party/fishhook/fishhook.c

@@ -0,0 +1,271 @@
+// Copyright (c) 2013, Facebook, Inc.
+// All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name Facebook nor the names of its contributors may be used to
+//     endorse or promote products derived from this software without specific
+//     prior written permission.
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "fishhook.h"
+
+#include <dlfcn.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <mach/mach.h>
+#include <mach/vm_map.h>
+#include <mach/vm_region.h>
+#include <mach-o/dyld.h>
+#include <mach-o/loader.h>
+#include <mach-o/nlist.h>
+#include <pthread.h>
+
+#ifdef __LP64__
+typedef struct mach_header_64 mach_header_t;
+typedef struct segment_command_64 segment_command_t;
+typedef struct section_64 section_t;
+typedef struct nlist_64 nlist_t;
+#define LC_SEGMENT_ARCH_DEPENDENT LC_SEGMENT_64
+#else
+typedef struct mach_header mach_header_t;
+typedef struct segment_command segment_command_t;
+typedef struct section section_t;
+typedef struct nlist nlist_t;
+#define LC_SEGMENT_ARCH_DEPENDENT LC_SEGMENT
+#endif
+
+#ifndef SEG_DATA_CONST
+#define SEG_DATA_CONST  "__DATA_CONST"
+#endif
+
+#ifndef SEG_AUTH_CONST
+#define SEG_AUTH_CONST  "__AUTH_CONST"
+#endif
+
+struct rebindings_entry {
+  struct rebinding *rebindings;
+  size_t rebindings_nel;
+  struct rebindings_entry *next;
+};
+
+static struct rebindings_entry *_rebindings_head;
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static int prepend_rebindings(struct rebindings_entry **rebindings_head,
+                              struct rebinding rebindings[],
+                              size_t nel) {
+  struct rebindings_entry *new_entry = (struct rebindings_entry *) malloc(sizeof(struct rebindings_entry));
+  if (!new_entry) {
+    return -1;
+  }
+  new_entry->rebindings = (struct rebinding *) malloc(sizeof(struct rebinding) * nel);
+  if (!new_entry->rebindings) {
+    free(new_entry);
+    return -1;
+  }
+  memcpy(new_entry->rebindings, rebindings, sizeof(struct rebinding) * nel);
+  new_entry->rebindings_nel = nel;
+  new_entry->next = *rebindings_head;
+  *rebindings_head = new_entry;
+  return 0;
+}
+
+static vm_prot_t get_protection(void *sectionStart) {
+  mach_port_t task = mach_task_self();
+  vm_size_t size = 0;
+  vm_address_t address = (vm_address_t)sectionStart;
+  memory_object_name_t object;
+#if __LP64__
+  mach_msg_type_number_t count = VM_REGION_BASIC_INFO_COUNT_64;
+  vm_region_basic_info_data_64_t info;
+  kern_return_t info_ret = vm_region_64(
+      task, &address, &size, VM_REGION_BASIC_INFO_64, (vm_region_info_64_t)&info, &count, &object);
+#else
+  mach_msg_type_number_t count = VM_REGION_BASIC_INFO_COUNT;
+  vm_region_basic_info_data_t info;
+  kern_return_t info_ret = vm_region(task, &address, &size, VM_REGION_BASIC_INFO, (vm_region_info_t)&info, &count, &object);
+#endif
+  if (info_ret == KERN_SUCCESS) {
+    return info.protection;
+  } else {
+    return VM_PROT_READ;
+  }
+}
+static void perform_rebinding_with_section(struct rebindings_entry *rebindings,
+                                           section_t *section,
+                                           intptr_t slide,
+                                           nlist_t *symtab,
+                                           char *strtab,
+                                           uint32_t *indirect_symtab) {
+  const bool isDataConst = strcmp(section->segname, SEG_DATA_CONST) == 0;
+  const bool isAuthConst = strcmp(section->segname, SEG_AUTH_CONST) == 0;
+  uint32_t *indirect_symbol_indices = indirect_symtab + section->reserved1;
+  void **indirect_symbol_bindings = (void **)((uintptr_t)slide + section->addr);
+  vm_prot_t oldProtection = VM_PROT_READ;
+  vm_size_t trunc_address = (vm_size_t)indirect_symbol_bindings;
+  vm_size_t trunc_size = 0;
+  if (isDataConst || isAuthConst) {
+    trunc_address = trunc_page((vm_size_t)indirect_symbol_bindings);
+    trunc_size =(vm_size_t)indirect_symbol_bindings -trunc_address;
+    pthread_mutex_lock(&mutex);
+    oldProtection = get_protection((void *)trunc_address);
+    mprotect((void *)trunc_address, section->size+trunc_size, PROT_READ | PROT_WRITE);
+  }
+  for (uint i = 0; i < section->size / sizeof(void *); i++) {
+    uint32_t symtab_index = indirect_symbol_indices[i];
+    if (symtab_index == INDIRECT_SYMBOL_ABS || symtab_index == INDIRECT_SYMBOL_LOCAL ||
+        symtab_index == (INDIRECT_SYMBOL_LOCAL | INDIRECT_SYMBOL_ABS)) {
+      continue;
+    }
+    uint32_t strtab_offset = symtab[symtab_index].n_un.n_strx;
+    char *symbol_name = strtab + strtab_offset;
+    bool symbol_name_longer_than_1 = symbol_name[0] && symbol_name[1];
+    struct rebindings_entry *cur = rebindings;
+    while (cur) {
+      for (uint j = 0; j < cur->rebindings_nel; j++) {
+        if (symbol_name_longer_than_1 &&
+            strcmp(&symbol_name[1], cur->rebindings[j].name) == 0) {
+          if (cur->rebindings[j].replaced != NULL &&
+              indirect_symbol_bindings[i] != cur->rebindings[j].replacement) {
+            *(cur->rebindings[j].replaced) = indirect_symbol_bindings[i];
+          }
+          indirect_symbol_bindings[i] = cur->rebindings[j].replacement;
+          goto symbol_loop;
+        }
+      }
+      cur = cur->next;
+    }
+  symbol_loop:;
+  }
+  if (isDataConst || isAuthConst) {
+    int protection = 0;
+    if (oldProtection & VM_PROT_READ) {
+      protection |= PROT_READ;
+    }
+    if (oldProtection & VM_PROT_WRITE) {
+      protection |= PROT_WRITE;
+    }
+    if (oldProtection & VM_PROT_EXECUTE) {
+      protection |= PROT_EXEC;
+    }
+    mprotect((void *)trunc_address, section->size+trunc_size, protection);
+    pthread_mutex_unlock(&mutex);
+  }
+}
+
+static void rebind_symbols_for_image(struct rebindings_entry *rebindings,
+                                     const struct mach_header *header,
+                                     intptr_t slide) {
+  Dl_info info;
+  if (dladdr(header, &info) == 0) {
+    return;
+  }
+
+  segment_command_t *cur_seg_cmd;
+  segment_command_t *linkedit_segment = NULL;
+  struct symtab_command* symtab_cmd = NULL;
+  struct dysymtab_command* dysymtab_cmd = NULL;
+
+  uintptr_t cur = (uintptr_t)header + sizeof(mach_header_t);
+  for (uint i = 0; i < header->ncmds; i++, cur += cur_seg_cmd->cmdsize) {
+    cur_seg_cmd = (segment_command_t *)cur;
+    if (cur_seg_cmd->cmd == LC_SEGMENT_ARCH_DEPENDENT) {
+      if (strcmp(cur_seg_cmd->segname, SEG_LINKEDIT) == 0) {
+        linkedit_segment = cur_seg_cmd;
+      }
+    } else if (cur_seg_cmd->cmd == LC_SYMTAB) {
+      symtab_cmd = (struct symtab_command*)cur_seg_cmd;
+    } else if (cur_seg_cmd->cmd == LC_DYSYMTAB) {
+      dysymtab_cmd = (struct dysymtab_command*)cur_seg_cmd;
+    }
+  }
+
+  if (!symtab_cmd || !dysymtab_cmd || !linkedit_segment ||
+      !dysymtab_cmd->nindirectsyms) {
+    return;
+  }
+
+  // Find base symbol/string table addresses
+  uintptr_t linkedit_base = (uintptr_t)slide + linkedit_segment->vmaddr - linkedit_segment->fileoff;
+  nlist_t *symtab = (nlist_t *)(linkedit_base + symtab_cmd->symoff);
+  char *strtab = (char *)(linkedit_base + symtab_cmd->stroff);
+
+  // Get indirect symbol table (array of uint32_t indices into symbol table)
+  uint32_t *indirect_symtab = (uint32_t *)(linkedit_base + dysymtab_cmd->indirectsymoff);
+
+  cur = (uintptr_t)header + sizeof(mach_header_t);
+  for (uint i = 0; i < header->ncmds; i++, cur += cur_seg_cmd->cmdsize) {
+    cur_seg_cmd = (segment_command_t *)cur;
+    if (cur_seg_cmd->cmd == LC_SEGMENT_ARCH_DEPENDENT) {
+      if (strcmp(cur_seg_cmd->segname, SEG_DATA) != 0 &&
+          strcmp(cur_seg_cmd->segname, SEG_DATA_CONST) != 0 &&
+          strcmp(cur_seg_cmd->segname, SEG_AUTH_CONST) != 0) {
+        continue;
+      }
+      for (uint j = 0; j < cur_seg_cmd->nsects; j++) {
+        section_t *sect =
+          (section_t *)(cur + sizeof(segment_command_t)) + j;
+        if ((sect->flags & SECTION_TYPE) == S_LAZY_SYMBOL_POINTERS) {
+          perform_rebinding_with_section(rebindings, sect, slide, symtab, strtab, indirect_symtab);
+        }
+        if ((sect->flags & SECTION_TYPE) == S_NON_LAZY_SYMBOL_POINTERS) {
+          perform_rebinding_with_section(rebindings, sect, slide, symtab, strtab, indirect_symtab);
+        }
+      }
+    }
+  }
+}
+
+static void _rebind_symbols_for_image(const struct mach_header *header,
+                                      intptr_t slide) {
+    rebind_symbols_for_image(_rebindings_head, header, slide);
+}
+
+int rebind_symbols_image(void *header,
+                         intptr_t slide,
+                         struct rebinding rebindings[],
+                         size_t rebindings_nel) {
+    struct rebindings_entry *rebindings_head = NULL;
+    int retval = prepend_rebindings(&rebindings_head, rebindings, rebindings_nel);
+    rebind_symbols_for_image(rebindings_head, (const struct mach_header *) header, slide);
+    if (rebindings_head) {
+      free(rebindings_head->rebindings);
+    }
+    free(rebindings_head);
+    return retval;
+}
+
+int rebind_symbols(struct rebinding rebindings[], size_t rebindings_nel) {
+  int retval = prepend_rebindings(&_rebindings_head, rebindings, rebindings_nel);
+  if (retval < 0) {
+    return retval;
+  }
+  // If this was the first call, register callback for image additions (which is also invoked for
+  // existing images, otherwise, just run on existing images
+  if (!_rebindings_head->next) {
+    _dyld_register_func_for_add_image(_rebind_symbols_for_image);
+  } else {
+    uint32_t c = _dyld_image_count();
+    for (uint32_t i = 0; i < c; i++) {
+      _rebind_symbols_for_image(_dyld_get_image_header(i), _dyld_get_image_vmaddr_slide(i));
+    }
+  }
+  return retval;
+}

ios/third_party/fishhook/fishhook.h

@@ -0,0 +1,76 @@
+// Copyright (c) 2013, Facebook, Inc.
+// All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name Facebook nor the names of its contributors may be used to
+//     endorse or promote products derived from this software without specific
+//     prior written permission.
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef fishhook_h
+#define fishhook_h
+
+#include <stddef.h>
+#include <stdint.h>
+
+#if !defined(FISHHOOK_EXPORT)
+#define FISHHOOK_VISIBILITY __attribute__((visibility("hidden")))
+#else
+#define FISHHOOK_VISIBILITY __attribute__((visibility("default")))
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif //__cplusplus
+
+/*
+ * A structure representing a particular intended rebinding from a symbol
+ * name to its replacement
+ */
+struct rebinding {
+  const char *name;
+  void *replacement;
+  void **replaced;
+};
+
+/*
+ * For each rebinding in rebindings, rebinds references to external, indirect
+ * symbols with the specified name to instead point at replacement for each
+ * image in the calling process as well as for all future images that are loaded
+ * by the process. If rebind_functions is called more than once, the symbols to
+ * rebind are added to the existing list of rebindings, and if a given symbol
+ * is rebound more than once, the later rebinding will take precedence.
+ */
+FISHHOOK_VISIBILITY
+int rebind_symbols(struct rebinding rebindings[], size_t rebindings_nel);
+
+/*
+ * Rebinds as above, but only in the specified image. The header should point
+ * to the mach-o header, the slide should be the slide offset. Others as above.
+ */
+FISHHOOK_VISIBILITY
+int rebind_symbols_image(void *header,
+                         intptr_t slide,
+                         struct rebinding rebindings[],
+                         size_t rebindings_nel);
+
+#ifdef __cplusplus
+}
+#endif //__cplusplus
+
+#endif //fishhook_h
+