160 lines
3.6 KiB
C
160 lines
3.6 KiB
C
/* Pi-hole: A black hole for Internet advertisements
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* (c) 2021 Pi-hole, LLC (https://pi-hole.net)
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* Network-wide ad blocking via your own hardware.
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*
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* FTL Engine
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* /proc system subroutines
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*
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* This file is copyright under the latest version of the EUPL.
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* Please see LICENSE file for your rights under this license. */
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#include "FTL.h"
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#include "procps.h"
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#include "log.h"
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#include <dirent.h>
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// getpid()
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#include <unistd.h>
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#define PROCESS_NAME "pihole-FTL"
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static bool get_process_name(const pid_t pid, char name[16])
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{
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if(pid == 0)
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{
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strcpy(name, "init");
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return true;
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}
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// Try to open comm file
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char filename[sizeof("/proc/%u/task/%u/comm") + sizeof(int)*3 * 2];
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snprintf(filename, sizeof(filename), "/proc/%d/comm", pid);
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FILE *f = fopen(filename, "r");
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if(f == NULL)
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return false;
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// Read name from opened file
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if(fscanf(f, "%15s", name) != 1)
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false;
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fclose(f);
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return true;
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}
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static bool get_process_ppid(const pid_t pid, pid_t *ppid)
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{
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// Try to open status file
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char filename[sizeof("/proc/%u/task/%u/status") + sizeof(int)*3 * 2];
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snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
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FILE *f = fopen(filename, "r");
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if(f == NULL)
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return false;
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// Read comm from opened file
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char buffer[128];
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while(fgets(buffer, sizeof(buffer), f) != NULL)
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{
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if(sscanf(buffer, "PPid: %d\n", ppid) == 1)
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break;
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}
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fclose(f);
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return true;
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}
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static bool get_process_creation_time(const pid_t pid, char timestr[84])
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{
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// Try to open comm file
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char filename[sizeof("/proc/%u/task/%u/comm") + sizeof(int)*3 * 2];
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snprintf(filename, sizeof(filename), "/proc/%d/comm", pid);
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struct stat st;
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if(stat(filename, &st) < 0)
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return false;
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get_timestr(timestr, st.st_ctim.tv_sec, false);
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return true;
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}
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bool check_running_FTL(void)
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{
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DIR *dirPos;
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struct dirent *entry;
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const pid_t ourselves = getpid();
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bool process_running = false;
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// Open /proc
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errno = 0;
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if ((dirPos = opendir("/proc")) == NULL)
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{
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logg("Failed to access /proc: %s", strerror(errno));
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return false;
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}
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// Loop over entries in /proc
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// This is much more efficient than iterating over all possible PIDs
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pid_t last_pid = 0;
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size_t last_len = 0u;
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while ((entry = readdir(dirPos)) != NULL)
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{
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// We are only interested in subdirectories of /proc
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if(entry->d_type != DT_DIR)
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continue;
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// We are only interested in PID subdirectories
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if(entry->d_name[0] < '0' || entry->d_name[0] > '9')
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continue;
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// Extract PID
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const pid_t pid = strtol(entry->d_name, NULL, 10);
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// Skip our own process
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if(pid == ourselves)
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continue;
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// Get process name
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char name[16] = { 0 };
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if(!get_process_name(pid, name))
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continue;
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// Only process this is this is our own process
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if(strcasecmp(name, PROCESS_NAME) != 0)
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continue;
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// Get parent process ID (PPID)
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pid_t ppid;
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if(!get_process_ppid(pid, &ppid))
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continue;
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char ppid_name[16] = { 0 };
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if(!get_process_name(ppid, ppid_name))
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continue;
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char timestr[84] = { 0 };
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get_process_creation_time(pid, timestr);
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// If this is the first process we log, add a header
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if(!process_running)
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{
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process_running = true;
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logg("HINT: %s is already running!", PROCESS_NAME);
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}
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if(last_pid != ppid)
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{
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// Independent process, may be child of init/systemd
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logg("%s (%d) ──> %s (PID %d, started %s)",
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ppid_name, ppid, name, pid, timestr);
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last_pid = pid;
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last_len = snprintf(NULL, 0, "%s (%d) ──> ", ppid_name, ppid);
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}
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else
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{
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// Process parented by the one we analyzed before,
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// highlight their relationship
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logg("%*s └─> %s (PID %d, started %s)",
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(int)last_len, "", name, pid, timestr);
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}
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}
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closedir(dirPos);
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return process_running;
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}
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