1 /*- 2 * Copyright (c) 2008 John Birrell (jb@freebsd.org) 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include "_libproc.h" 30 #include <err.h> 31 #include <errno.h> 32 #include <fcntl.h> 33 #include <limits.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <unistd.h> 37 #include <sys/wait.h> 38 39 int 40 proc_attach(pid_t pid, int flags, struct proc_handle **pphdl) 41 { 42 struct proc_handle *phdl; 43 struct kevent kev; 44 int error = 0; 45 int status; 46 47 if (pid == 0 || pphdl == NULL) 48 return (EINVAL); 49 50 /* 51 * Allocate memory for the process handle, a structure containing 52 * all things related to the process. 53 */ 54 if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) 55 return (ENOMEM); 56 57 memset(phdl, 0, sizeof(struct proc_handle)); 58 phdl->pid = pid; 59 phdl->flags = flags; 60 phdl->status = PS_RUN; 61 62 EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, 63 0, NULL); 64 65 if ((phdl->kq = kqueue()) == -1) 66 err(1, "ERROR: cannot create kernel evet queue"); 67 68 if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0) 69 err(2, "ERROR: cannot monitor child process %d", pid); 70 71 if (ptrace(PT_ATTACH, phdl->pid, NULL, 0) != 0) 72 error = errno; 73 74 /* Wait for the child process to stop. */ 75 else if (waitpid(pid, &status, WUNTRACED) == -1) 76 err(3, "ERROR: child process %d didn't stop as expected", pid); 77 78 /* Check for an unexpected status. */ 79 else if (WIFSTOPPED(status) == 0) 80 err(4, "ERROR: child process %d status 0x%x", pid, status); 81 else 82 phdl->status = PS_STOP; 83 84 if (error) 85 proc_free(phdl); 86 else 87 *pphdl = phdl; 88 89 return (error); 90 } 91 92 int 93 proc_create(const char *file, char * const *argv, struct proc_handle **pphdl) 94 { 95 struct proc_handle *phdl; 96 struct kevent kev; 97 int error = 0; 98 int status; 99 pid_t pid; 100 101 /* 102 * Allocate memory for the process handle, a structure containing 103 * all things related to the process. 104 */ 105 if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) 106 return (ENOMEM); 107 108 /* Fork a new process. */ 109 if ((pid = fork()) == -1) 110 error = errno; 111 else if (pid == 0) { 112 /* The child expects to be traced. */ 113 if (ptrace(PT_TRACE_ME, 0, 0, 0) != 0) 114 _exit(1); 115 116 /* Execute the specified file: */ 117 execvp(file, argv); 118 119 /* Couldn't execute the file. */ 120 _exit(2); 121 } else { 122 /* The parent owns the process handle. */ 123 memset(phdl, 0, sizeof(struct proc_handle)); 124 phdl->pid = pid; 125 phdl->status = PS_IDLE; 126 127 EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, 128 0, NULL); 129 130 if ((phdl->kq = kqueue()) == -1) 131 err(1, "ERROR: cannot create kernel evet queue"); 132 133 if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0) 134 err(2, "ERROR: cannot monitor child process %d", pid); 135 136 /* Wait for the child process to stop. */ 137 if (waitpid(pid, &status, WUNTRACED) == -1) 138 err(3, "ERROR: child process %d didn't stop as expected", pid); 139 140 /* Check for an unexpected status. */ 141 if (WIFSTOPPED(status) == 0) 142 err(4, "ERROR: child process %d status 0x%x", pid, status); 143 else 144 phdl->status = PS_STOP; 145 } 146 147 if (error) 148 proc_free(phdl); 149 else 150 *pphdl = phdl; 151 152 return (error); 153 } 154 155 void 156 proc_free(struct proc_handle *phdl) 157 { 158 free(phdl); 159 } 160