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