diff options
Diffstat (limited to 'lib/libproc/proc_create.c')
| -rw-r--r-- | lib/libproc/proc_create.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/lib/libproc/proc_create.c b/lib/libproc/proc_create.c new file mode 100644 index 0000000..8648999 --- /dev/null +++ b/lib/libproc/proc_create.c @@ -0,0 +1,159 @@ +/*- + * Copyright (c) 2008 John Birrell (jb@freebsd.org) + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include "_libproc.h" +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/wait.h> + +int +proc_attach(pid_t pid, int flags, struct proc_handle **pphdl) +{ + struct proc_handle *phdl; + struct kevent kev; + int error = 0; + int status; + + if (pid == 0 || pphdl == NULL) + return (EINVAL); + + /* + * Allocate memory for the process handle, a structure containing + * all things related to the process. + */ + if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) + return (ENOMEM); + + memset(phdl, 0, sizeof(struct proc_handle)); + phdl->pid = pid; + phdl->flags = flags; + phdl->status = PS_RUN; + + EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, + 0, NULL); + + if ((phdl->kq = kqueue()) == -1) + err(1, "ERROR: cannot create kernel evet queue"); + + if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0) + err(2, "ERROR: cannot monitor child process %d", pid); + + if (ptrace(PT_ATTACH, phdl->pid, NULL, 0) != 0) + error = errno; + + /* Wait for the child process to stop. */ + else if (waitpid(pid, &status, WUNTRACED) == -1) + err(3, "ERROR: child process %d didn't stop as expected", pid); + + /* Check for an unexpected status. */ + else if (WIFSTOPPED(status) == 0) + err(4, "ERROR: child process %d status 0x%x", pid, status); + else + phdl->status = PS_STOP; + + if (error) + proc_free(phdl); + else + *pphdl = phdl; + + return (error); +} + +int +proc_create(const char *file, char * const *argv, struct proc_handle **pphdl) +{ + struct proc_handle *phdl; + struct kevent kev; + int error = 0; + int status; + pid_t pid; + + /* + * Allocate memory for the process handle, a structure containing + * all things related to the process. + */ + if ((phdl = malloc(sizeof(struct proc_handle))) == NULL) + return (ENOMEM); + + /* Fork a new process. */ + if ((pid = fork()) == -1) + error = errno; + else if (pid == 0) { + /* The child expects to be traced. */ + if (ptrace(PT_TRACE_ME, 0, 0, 0) != 0) + _exit(1); + + /* Execute the specified file: */ + execvp(file, argv); + + /* Couldn't execute the file. */ + _exit(2); + } else { + /* The parent owns the process handle. */ + memset(phdl, 0, sizeof(struct proc_handle)); + phdl->pid = pid; + phdl->status = PS_IDLE; + + EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, + 0, NULL); + + if ((phdl->kq = kqueue()) == -1) + err(1, "ERROR: cannot create kernel evet queue"); + + if (kevent(phdl->kq, &kev, 1, NULL, 0, NULL) < 0) + err(2, "ERROR: cannot monitor child process %d", pid); + + /* Wait for the child process to stop. */ + if (waitpid(pid, &status, WUNTRACED) == -1) + err(3, "ERROR: child process %d didn't stop as expected", pid); + + /* Check for an unexpected status. */ + if (WIFSTOPPED(status) == 0) + err(4, "ERROR: child process %d status 0x%x", pid, status); + else + phdl->status = PS_STOP; + } + + if (error) + proc_free(phdl); + else + *pphdl = phdl; + + return (error); +} + +void +proc_free(struct proc_handle *phdl) +{ + free(phdl); +} |
