1 /** 2 * @file daemon/opd_pipe.c 3 * Functions handling the $SESSIONDIR/opd_pipe FIFO special file. 4 * NOTE: This code is dealing with potentially insecure input. 5 * 6 * @remark Copyright 2008 OProfile authors 7 * @remark Read the file COPYING 8 * 9 * @author Daniel Hansel 10 */ 11 12 #include "opd_pipe.h" 13 #include "opd_printf.h" 14 #include "op_config.h" 15 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 #include <fcntl.h> 20 #include <unistd.h> 21 #include <errno.h> 22 #include <sys/stat.h> 23 24 static int fifo; 25 static FILE * fifo_fd = NULL; 26 opd_create_pipe(void)27void opd_create_pipe(void) 28 { 29 mode_t orig_umask = umask(0111); 30 if (mkfifo(op_pipe_file, 0666) == -1) { 31 if (errno != EEXIST) { 32 perror("oprofiled: couldn't create pipe: "); 33 exit(EXIT_FAILURE); 34 } 35 } 36 umask(orig_umask); 37 } 38 39 opd_open_pipe(void)40void opd_open_pipe(void) 41 { 42 fifo = open(op_pipe_file, O_RDONLY | O_NONBLOCK); 43 if (fifo == -1) { 44 perror("oprofiled: couldn't open pipe: "); 45 exit(EXIT_FAILURE); 46 } 47 } 48 49 opd_close_pipe(void)50void opd_close_pipe(void) 51 { 52 if (fifo_fd) 53 fclose(fifo_fd); 54 close(fifo); 55 } 56 57 is_jitconv_requested(void)58int is_jitconv_requested(void) 59 { 60 /* number of dropped (unknown) requests */ 61 static long nr_drops = 0; 62 /* modulus to output only a few warnings to avoid flooding oprofiled.log */ 63 static int mod_cnt_drops = 1; 64 char line[256]; 65 int i, ret = 0; 66 67 /* get a file descriptor to the pipe */ 68 if (!fifo_fd) 69 fifo_fd = fdopen(fifo, "r"); 70 71 if (fifo_fd == NULL) { 72 perror("oprofiled: couldn't create file descriptor: "); 73 exit(EXIT_FAILURE); 74 } 75 76 /* read up to 99 lines to check for 'do_jitconv' */ 77 for (i = 0; i < 99; i++) { 78 /* just break if no new line is found */ 79 if (fgets(line, 256, fifo_fd) == NULL) 80 break; 81 line[strlen(line) - 1] = '\0'; 82 83 if (strstr(line, "do_jitconv") != NULL) { 84 ret = 1; 85 } else { 86 nr_drops++; 87 88 if (nr_drops % mod_cnt_drops == 0) { 89 printf( 90 "Warning: invalid pipe request received (dropped request(s): %ld)\n", 91 nr_drops); 92 /* increase modulus to avoid flooding log file */ 93 mod_cnt_drops *= 5; 94 } 95 } 96 } 97 98 return ret; 99 } 100