Set CLOEXEC flag on files we open.

When running programs in server mode, connect stdin and stdout to /dev/null
This commit is contained in:
Dianne Skoll
2024-02-29 09:22:15 -05:00
parent 8efde3e9af
commit 0f782f7697
5 changed files with 64 additions and 11 deletions

View File

@@ -1151,7 +1151,7 @@ int TriggerReminder(ParsePtr p, Trigger *t, TimeTrig *tim, int dse, int is_queue
case MSG_TYPE:
case PASSTHRU_TYPE:
if (msg_command) {
DoMsgCommand(msg_command, DBufValue(&buf));
DoMsgCommand(msg_command, DBufValue(&buf), is_queued);
} else {
if (output) {
DBufPuts(output, DBufValue(&buf));
@@ -1171,7 +1171,7 @@ int TriggerReminder(ParsePtr p, Trigger *t, TimeTrig *tim, int dse, int is_queue
break;
case RUN_TYPE:
System(DBufValue(&buf));
System(DBufValue(&buf), is_queued);
break;
default: /* Unknown/illegal type? */
@@ -1398,7 +1398,7 @@ static int ParsePriority(ParsePtr s, Trigger *t)
/* Execute the '-k' command, escaping shell chars in message. */
/* */
/***************************************************************/
int DoMsgCommand(char const *cmd, char const *msg)
int DoMsgCommand(char const *cmd, char const *msg, int is_queued)
{
int r;
int i, l;
@@ -1435,7 +1435,7 @@ int DoMsgCommand(char const *cmd, char const *msg)
}
r = OK;
System(DBufValue(&execBuffer));
System(DBufValue(&execBuffer), is_queued);
finished:
DBufFree(&buf);

View File

@@ -15,7 +15,7 @@
#include "config.h"
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
@@ -100,6 +100,18 @@ static int CheckSafety (void);
static int CheckSafetyAux (struct stat *statbuf);
static int PopFile (void);
static int IncludeCmd(char const *);
void set_cloexec(int fd)
{
int flags;
flags = fcntl(fd, F_GETFD);
if (flags >= 0) {
flags |= FD_CLOEXEC;
fcntl(fd, F_SETFD, flags);
}
}
static void OpenPurgeFile(char const *fname, char const *mode)
{
DynamicBuffer fname_buf;
@@ -123,6 +135,7 @@ static void OpenPurgeFile(char const *fname, char const *mode)
if (!PurgeFP) {
fprintf(ErrFp, "Cannot open `%s' for writing: %s\n", DBufValue(&fname_buf), strerror(errno));
}
set_cloexec(fileno(PurgeFP));
DBufFree(&fname_buf);
}
@@ -327,6 +340,7 @@ int OpenFile(char const *fname)
}
} else {
fp = fopen(fname, "r");
if (fp) set_cloexec(fileno(fp));
if (DebugFlag & DB_TRACE_FILES) {
fprintf(ErrFp, "Reading `%s': Opening file on disk\n", fname);
}
@@ -346,6 +360,7 @@ int OpenFile(char const *fname)
if (strcmp(fname, "-")) {
fp = fopen(fname, "r");
if (!fp || !CheckSafety()) return E_CANT_OPEN;
set_cloexec(fileno(fp));
if (PurgeMode) OpenPurgeFile(fname, "w");
} else {
fp = stdin;
@@ -542,6 +557,7 @@ static int PopFile(void)
if (strcmp(i->filename, "-")) {
fp = fopen(i->filename, "r");
if (!fp || !CheckSafety()) return E_CANT_OPEN;
set_cloexec(fileno(fp));
if (PurgeMode) OpenPurgeFile(i->filename, "a");
} else {
fp = stdin;

View File

@@ -14,6 +14,8 @@
#define _XOPEN_SOURCE 600
#include "config.h"
#include <fcntl.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
@@ -1654,11 +1656,45 @@ SaveLastTimeTrig(TimeTrig const *t)
memcpy(&LastTimeTrig, t, sizeof(LastTimeTrig));
}
/* Wrapper to ignore warnings about ignoring return value of system() */
/* Wrapper to ignore warnings about ignoring return value of system()
Also redirects stdin and stdout to /dev/null for queued reminders */
void
System(char const *cmd)
System(char const *cmd, int is_queued)
{
int r;
pid_t kid;
int fd;
int status;
if (is_queued && IsServerMode()) {
/* Server mode... redirect stdin and stdout to /dev/null */
kid = fork();
if (kid == (pid_t) -1) {
/* Fork failed... nothing we can do */
return;
} else if (kid == 0) {
/* In the child */
(void) close(STDIN_FILENO);
(void) close(STDOUT_FILENO);
fd = open("/dev/null", O_RDONLY);
if (fd >= 0 && fd != STDIN_FILENO) {
dup2(fd, STDIN_FILENO);
close(STDIN_FILENO);
}
fd = open("/dev/null", O_WRONLY);
if (fd >= 0 && fd != STDOUT_FILENO) {
dup2(fd, STDOUT_FILENO);
close(STDOUT_FILENO);
}
} else {
/* In the parent */
while (waitpid(kid, &status, 0) != kid) {
continue;
}
return;
}
}
/* This is the child process */
r = system(cmd);
if (r == 0) {
return;

View File

@@ -118,7 +118,7 @@ void DestroyVars (int all);
int PreserveVar (char const *name);
int DoPreserve (Parser *p);
int DoSatRemind (Trigger *trig, TimeTrig *tt, ParsePtr p);
int DoMsgCommand (char const *cmd, char const *msg);
int DoMsgCommand (char const *cmd, char const *msg, int is_queued);
int ParseNonSpaceChar (ParsePtr p, int *err, int peek);
unsigned int HashVal (char const *str);
int DateOK (int y, int m, int d);
@@ -168,7 +168,7 @@ void PrintJSONKeyPairString(char const *name, char const *val);
void PrintJSONKeyPairDate(char const *name, int dse);
void PrintJSONKeyPairDateTime(char const *name, int dt);
void PrintJSONKeyPairTime(char const *name, int t);
void System(char const *cmd);
void System(char const *cmd, int queued);
int ShellEscape(char const *in, DynamicBuffer *out);
int AddGlobalOmit(int dse);
void set_lat_and_long_from_components(void);
@@ -179,6 +179,7 @@ int GetTerminalBackground(void);
char const *get_day_name(int wkday);
char const *get_month_name(int mon);
void set_cloexec(int fd);
int push_call(char const *filename, char const *func, int lineno);
void clear_callstack(void);
int print_callstack(FILE *fp);

View File

@@ -136,7 +136,7 @@ void IssueSortedReminders(void)
switch(cur->typ) {
case MSG_TYPE:
if (MsgCommand && *MsgCommand) {
DoMsgCommand(MsgCommand, cur->text);
DoMsgCommand(MsgCommand, cur->text, 0);
} else {
if (cur->trigdate != olddate) {
IssueSortBanner(cur->trigdate);
@@ -155,7 +155,7 @@ void IssueSortedReminders(void)
break;
case RUN_TYPE:
System(cur->text);
System(cur->text, 0);
break;
}