process_iterator_mac.cc revision 868fa2fe829687343ffae624259930155e16dbd8 
1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/process/process_iterator.h"
6
7#include <errno.h>
8#include <sys/sysctl.h>
9#include <sys/types.h>
10
11#include "base/logging.h"
12#include "base/strings/string_util.h"
13
14namespace base {
15
16ProcessIterator::ProcessIterator(const ProcessFilter* filter)
17    : index_of_kinfo_proc_(0),
18      filter_(filter) {
19  // Get a snapshot of all of my processes (yes, as we loop it can go stale, but
20  // but trying to find where we were in a constantly changing list is basically
21  // impossible.
22
23  int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_UID, geteuid() };
24
25  // Since more processes could start between when we get the size and when
26  // we get the list, we do a loop to keep trying until we get it.
27  bool done = false;
28  int try_num = 1;
29  const int max_tries = 10;
30  do {
31    // Get the size of the buffer
32    size_t len = 0;
33    if (sysctl(mib, arraysize(mib), NULL, &len, NULL, 0) < 0) {
34      DLOG(ERROR) << "failed to get the size needed for the process list";
35      kinfo_procs_.resize(0);
36      done = true;
37    } else {
38      size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
39      // Leave some spare room for process table growth (more could show up
40      // between when we check and now)
41      num_of_kinfo_proc += 16;
42      kinfo_procs_.resize(num_of_kinfo_proc);
43      len = num_of_kinfo_proc * sizeof(struct kinfo_proc);
44      // Load the list of processes
45      if (sysctl(mib, arraysize(mib), &kinfo_procs_[0], &len, NULL, 0) < 0) {
46        // If we get a mem error, it just means we need a bigger buffer, so
47        // loop around again.  Anything else is a real error and give up.
48        if (errno != ENOMEM) {
49          DLOG(ERROR) << "failed to get the process list";
50          kinfo_procs_.resize(0);
51          done = true;
52        }
53      } else {
54        // Got the list, just make sure we're sized exactly right
55        size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
56        kinfo_procs_.resize(num_of_kinfo_proc);
57        done = true;
58      }
59    }
60  } while (!done && (try_num++ < max_tries));
61
62  if (!done) {
63    DLOG(ERROR) << "failed to collect the process list in a few tries";
64    kinfo_procs_.resize(0);
65  }
66}
67
68ProcessIterator::~ProcessIterator() {
69}
70
71bool ProcessIterator::CheckForNextProcess() {
72  std::string data;
73  for (; index_of_kinfo_proc_ < kinfo_procs_.size(); ++index_of_kinfo_proc_) {
74    kinfo_proc& kinfo = kinfo_procs_[index_of_kinfo_proc_];
75
76    // Skip processes just awaiting collection
77    if ((kinfo.kp_proc.p_pid > 0) && (kinfo.kp_proc.p_stat == SZOMB))
78      continue;
79
80    int mib[] = { CTL_KERN, KERN_PROCARGS, kinfo.kp_proc.p_pid };
81
82    // Find out what size buffer we need.
83    size_t data_len = 0;
84    if (sysctl(mib, arraysize(mib), NULL, &data_len, NULL, 0) < 0) {
85      DVPLOG(1) << "failed to figure out the buffer size for a commandline";
86      continue;
87    }
88
89    data.resize(data_len);
90    if (sysctl(mib, arraysize(mib), &data[0], &data_len, NULL, 0) < 0) {
91      DVPLOG(1) << "failed to fetch a commandline";
92      continue;
93    }
94
95    // |data| contains all the command line parameters of the process, separated
96    // by blocks of one or more null characters. We tokenize |data| into a
97    // vector of strings using '\0' as a delimiter and populate
98    // |entry_.cmd_line_args_|.
99    std::string delimiters;
100    delimiters.push_back('\0');
101    Tokenize(data, delimiters, &entry_.cmd_line_args_);
102
103    // |data| starts with the full executable path followed by a null character.
104    // We search for the first instance of '\0' and extract everything before it
105    // to populate |entry_.exe_file_|.
106    size_t exec_name_end = data.find('\0');
107    if (exec_name_end == std::string::npos) {
108      DLOG(ERROR) << "command line data didn't match expected format";
109      continue;
110    }
111
112    entry_.pid_ = kinfo.kp_proc.p_pid;
113    entry_.ppid_ = kinfo.kp_eproc.e_ppid;
114    entry_.gid_ = kinfo.kp_eproc.e_pgid;
115    size_t last_slash = data.rfind('/', exec_name_end);
116    if (last_slash == std::string::npos)
117      entry_.exe_file_.assign(data, 0, exec_name_end);
118    else
119      entry_.exe_file_.assign(data, last_slash + 1,
120                              exec_name_end - last_slash - 1);
121    // Start w/ the next entry next time through
122    ++index_of_kinfo_proc_;
123    // Done
124    return true;
125  }
126  return false;
127}
128
129bool NamedProcessIterator::IncludeEntry() {
130  return (executable_name_ == entry().exe_file() &&
131          ProcessIterator::IncludeEntry());
132}
133
134}  // namespace base
135