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
  11 #include "base/logging.h"
  12 #include "base/strings/string_util.h"
  13
  14 namespace base {
  15
  16 ProcessIterator::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
  68 ProcessIterator::~ProcessIterator() {
  69 }
  70
  71 bool 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
 129 bool NamedProcessIterator::IncludeEntry() {
 130   return (executable_name_ == entry().exe_file() &&
 131           ProcessIterator::IncludeEntry());
 132 }
 133
 134 }  // namespace base