base/process/process_iterator_mac.cc

   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 #include <unistd.h>
  11
  12 #include "base/logging.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_util.h"
  15
  16 namespace base {
  17
  18 ProcessIterator::ProcessIterator(const ProcessFilter* filter)
  19     : index_of_kinfo_proc_(0),
  20       filter_(filter) {
  21   // Get a snapshot of all of my processes (yes, as we loop it can go stale, but
  22   // but trying to find where we were in a constantly changing list is basically
  23   // impossible.
  24
  25   int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_UID,
  26                 static_cast<int>(geteuid()) };
  27
  28   // Since more processes could start between when we get the size and when
  29   // we get the list, we do a loop to keep trying until we get it.
  30   bool done = false;
  31   int try_num = 1;
  32   const int max_tries = 10;
  33   do {
  34     // Get the size of the buffer
  35     size_t len = 0;
  36     if (sysctl(mib, arraysize(mib), NULL, &len, NULL, 0) < 0) {
  37       DLOG(ERROR) << "failed to get the size needed for the process list";
  38       kinfo_procs_.resize(0);
  39       done = true;
  40     } else {
  41       size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
  42       // Leave some spare room for process table growth (more could show up
  43       // between when we check and now)
  44       num_of_kinfo_proc += 16;
  45       kinfo_procs_.resize(num_of_kinfo_proc);
  46       len = num_of_kinfo_proc * sizeof(struct kinfo_proc);
  47       // Load the list of processes
  48       if (sysctl(mib, arraysize(mib), &kinfo_procs_[0], &len, NULL, 0) < 0) {
  49         // If we get a mem error, it just means we need a bigger buffer, so
  50         // loop around again.  Anything else is a real error and give up.
  51         if (errno != ENOMEM) {
  52           DLOG(ERROR) << "failed to get the process list";
  53           kinfo_procs_.resize(0);
  54           done = true;
  55         }
  56       } else {
  57         // Got the list, just make sure we're sized exactly right
  58         size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
  59         kinfo_procs_.resize(num_of_kinfo_proc);
  60         done = true;
  61       }
  62     }
  63   } while (!done && (try_num++ < max_tries));
  64
  65   if (!done) {
  66     DLOG(ERROR) << "failed to collect the process list in a few tries";
  67     kinfo_procs_.resize(0);
  68   }
  69 }
  70
  71 ProcessIterator::~ProcessIterator() {
  72 }
  73
  74 bool ProcessIterator::CheckForNextProcess() {
  75   std::string data;
  76   for (; index_of_kinfo_proc_ < kinfo_procs_.size(); ++index_of_kinfo_proc_) {
  77     kinfo_proc& kinfo = kinfo_procs_[index_of_kinfo_proc_];
  78
  79     // Skip processes just awaiting collection
  80     if ((kinfo.kp_proc.p_pid > 0) && (kinfo.kp_proc.p_stat == SZOMB))
  81       continue;
  82
  83     int mib[] = { CTL_KERN, KERN_PROCARGS, kinfo.kp_proc.p_pid };
  84
  85     // Find out what size buffer we need.
  86     size_t data_len = 0;
  87     if (sysctl(mib, arraysize(mib), NULL, &data_len, NULL, 0) < 0) {
  88       DVPLOG(1) << "failed to figure out the buffer size for a commandline";
  89       continue;
  90     }
  91
  92     data.resize(data_len);
  93     if (sysctl(mib, arraysize(mib), &data[0], &data_len, NULL, 0) < 0) {
  94       DVPLOG(1) << "failed to fetch a commandline";
  95       continue;
  96     }
  97
  98     // |data| contains all the command line parameters of the process, separated
  99     // by blocks of one or more null characters. We tokenize |data| into a
 100     // vector of strings using '\0' as a delimiter and populate
 101     // |entry_.cmd_line_args_|.
 102     std::string delimiters;
 103     delimiters.push_back('\0');
 104     entry_.cmd_line_args_ = SplitString(data, delimiters,
 105                                         KEEP_WHITESPACE, SPLIT_WANT_NONEMPTY);
 106
 107     // |data| starts with the full executable path followed by a null character.
 108     // We search for the first instance of '\0' and extract everything before it
 109     // to populate |entry_.exe_file_|.
 110     size_t exec_name_end = data.find('\0');
 111     if (exec_name_end == std::string::npos) {
 112       DLOG(ERROR) << "command line data didn't match expected format";
 113       continue;
 114     }
 115
 116     entry_.pid_ = kinfo.kp_proc.p_pid;
 117     entry_.ppid_ = kinfo.kp_eproc.e_ppid;
 118     entry_.gid_ = kinfo.kp_eproc.e_pgid;
 119     size_t last_slash = data.rfind('/', exec_name_end);
 120     if (last_slash == std::string::npos)
 121       entry_.exe_file_.assign(data, 0, exec_name_end);
 122     else
 123       entry_.exe_file_.assign(data, last_slash + 1,
 124                               exec_name_end - last_slash - 1);
 125     // Start w/ the next entry next time through
 126     ++index_of_kinfo_proc_;
 127     // Done
 128     return true;
 129   }
 130   return false;
 131 }
 132
 133 bool NamedProcessIterator::IncludeEntry() {
 134   return (executable_name_ == entry().exe_file() &&
 135           ProcessIterator::IncludeEntry());
 136 }
 137
 138 }  // namespace base