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