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