+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <err.h>
+#include <unistd.h>
+#include <poll.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <ccan/read_write_all/read_write_all.h>
+#include <ccan/failtest/failtest_proto.h>
+#include <ccan/failtest/failtest.h>
+
+bool (*failtest_hook)(struct failtest_call *history, unsigned num)
+= failtest_default_hook;
+
+unsigned int failtest_timeout_ms = 20000;
+
+const char *failpath;
+
+enum info_type {
+ WRITE,
+ FAILURE,
+ SUCCESS,
+ UNEXPECTED
+};
+
+struct write_info_hdr {
+ size_t len;
+ off_t offset;
+ int fd;
+};
+
+struct fd_orig {
+ int fd;
+ off_t offset;
+ size_t size;
+ bool dupped;
+};
+
+struct write_info {
+ struct write_info_hdr hdr;
+ char *data;
+ size_t oldlen;
+ char *olddata;
+};
+
+bool (*failtest_exit_check)(struct failtest_call *history, unsigned num);
+
+static struct failtest_call *history = NULL;
+static unsigned int history_num = 0;
+static int control_fd = -1;
+
+static struct write_info *writes = NULL;
+static unsigned int writes_num = 0;
+
+static struct write_info *child_writes = NULL;
+static unsigned int child_writes_num = 0;
+
+static struct fd_orig *fd_orig = NULL;
+static unsigned int fd_orig_num = 0;
+
+static const char info_to_arg[] = "mceoprw";
+
+static struct failtest_call *add_history_(enum failtest_call_type type,
+ const char *file,
+ unsigned int line,
+ const void *elem,
+ size_t elem_size)
+{
+ history = realloc(history, (history_num + 1) * sizeof(*history));
+ history[history_num].type = type;
+ history[history_num].file = file;
+ history[history_num].line = line;
+ memcpy(&history[history_num].u, elem, elem_size);
+ return &history[history_num++];
+}
+
+#define add_history(type, file, line, elem) \
+ add_history_((type), (file), (line), (elem), sizeof(*(elem)))
+
+static void save_fd_orig(int fd)
+{
+ unsigned int i;
+
+ for (i = 0; i < fd_orig_num; i++)
+ if (fd_orig[i].fd == fd)
+ return;
+
+ fd_orig = realloc(fd_orig, (fd_orig_num + 1) * sizeof(*fd_orig));
+ fd_orig[fd_orig_num].fd = fd;
+ fd_orig[fd_orig_num].dupped = false;
+ fd_orig[fd_orig_num].offset = lseek(fd, 0, SEEK_CUR);
+ fd_orig[fd_orig_num].size = lseek(fd, 0, SEEK_END);
+ lseek(fd, fd_orig[fd_orig_num].offset, SEEK_SET);
+ fd_orig_num++;
+}
+
+bool failtest_default_hook(struct failtest_call *history, unsigned num)
+{
+ return true;
+}
+
+static bool read_write_info(int fd)
+{
+ struct write_info_hdr hdr;
+
+ if (!read_all(fd, &hdr, sizeof(hdr)))
+ return false;
+
+ child_writes = realloc(child_writes,
+ (child_writes_num+1) * sizeof(child_writes[0]));
+ child_writes[child_writes_num].hdr = hdr;
+ child_writes[child_writes_num].data = malloc(hdr.len);
+ if (!read_all(fd, child_writes[child_writes_num].data, hdr.len))
+ return false;
+
+ child_writes_num++;
+ return true;
+}
+
+static void print_reproduce(void)
+{
+ unsigned int i;
+
+ printf("To reproduce: --failpath=");
+ for (i = 0; i < history_num; i++) {
+ if (history[i].fail)
+ printf("%c", toupper(info_to_arg[history[i].type]));
+ else
+ printf("%c", info_to_arg[history[i].type]);
+ }
+ printf("\n");
+}
+
+static void tell_parent(enum info_type type)
+{
+ if (control_fd != -1)
+ write_all(control_fd, &type, sizeof(type));
+}
+
+static void child_fail(const char *out, size_t outlen, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+
+ fprintf(stderr, "%.*s", (int)outlen, out);
+ print_reproduce();
+ tell_parent(FAILURE);
+ exit(1);
+}
+
+static pid_t child;
+
+static void hand_down(int signal)
+{
+ kill(child, signal);
+}
+
+static bool should_fail(struct failtest_call *call)
+{
+ int status;
+ int control[2], output[2];
+ enum info_type type = UNEXPECTED;
+ char *out = NULL;
+ size_t outlen = 0;
+
+ if (failpath) {
+ if (tolower(*failpath) != info_to_arg[call->type])
+ errx(1, "Failpath expected '%c' got '%c'\n",
+ info_to_arg[call->type], *failpath);
+ return isupper(*(failpath++));
+ }
+
+ if (!failtest_hook(history, history_num)) {
+ call->fail = false;
+ return false;
+ }
+
+ /* We're going to fail in the child. */
+ call->fail = true;
+ if (pipe(control) != 0 || pipe(output) != 0)
+ err(1, "opening pipe");
+
+ /* Prevent double-printing (in child and parent) */
+ fflush(stdout);
+ child = fork();
+ if (child == -1)
+ err(1, "forking failed");
+
+ if (child == 0) {
+ close(control[0]);
+ close(output[0]);
+ dup2(output[1], STDOUT_FILENO);
+ dup2(output[1], STDERR_FILENO);
+ if (output[1] != STDOUT_FILENO && output[1] != STDERR_FILENO)
+ close(output[1]);
+ control_fd = control[1];
+ return true;
+ }
+
+ signal(SIGUSR1, hand_down);
+
+ close(control[1]);
+ close(output[1]);
+
+ /* We grab output so we can display it; we grab writes so we
+ * can compare. */
+ do {
+ struct pollfd pfd[2];
+ int ret;
+
+ pfd[0].fd = output[0];
+ pfd[0].events = POLLIN|POLLHUP;
+ pfd[1].fd = control[0];
+ pfd[1].events = POLLIN|POLLHUP;
+
+ if (type == SUCCESS)
+ ret = poll(pfd, 1, failtest_timeout_ms);
+ else
+ ret = poll(pfd, 2, failtest_timeout_ms);
+
+ if (ret <= 0)
+ hand_down(SIGUSR1);
+
+ if (pfd[0].revents & POLLIN) {
+ ssize_t len;
+
+ out = realloc(out, outlen + 8192);
+ len = read(output[0], out + outlen, 8192);
+ outlen += len;
+ } else if (type != SUCCESS && (pfd[1].revents & POLLIN)) {
+ if (read_all(control[0], &type, sizeof(type))) {
+ if (type == WRITE) {
+ if (!read_write_info(control[0]))
+ break;
+ }
+ }
+ } else if (pfd[0].revents & POLLHUP) {
+ break;
+ }
+ } while (type != FAILURE);
+
+ close(output[0]);
+ close(control[0]);
+ waitpid(child, &status, 0);
+ if (!WIFEXITED(status))
+ child_fail(out, outlen, "Killed by signal %u: ",
+ WTERMSIG(status));
+ /* Child printed failure already, just pass up exit code. */
+ if (type == FAILURE) {
+ fprintf(stderr, "%.*s", (int)outlen, out);
+ tell_parent(type);
+ exit(WEXITSTATUS(status) ? WEXITSTATUS(status) : 1);
+ }
+ if (WEXITSTATUS(status) != 0)
+ child_fail(out, outlen, "Exited with status %i: ",
+ WEXITSTATUS(status));
+
+ free(out);
+ signal(SIGUSR1, SIG_DFL);
+
+ /* We continue onwards without failing. */
+ call->fail = false;
+ return false;
+}
+
+void *failtest_calloc(size_t nmemb, size_t size,
+ const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct calloc_call call;
+ call.nmemb = nmemb;
+ call.size = size;
+ p = add_history(FAILTEST_CALLOC, file, line, &call);
+
+ if (should_fail(p)) {
+ p->u.calloc.ret = NULL;
+ p->error = ENOMEM;
+ } else {
+ p->u.calloc.ret = calloc(nmemb, size);
+ }
+ errno = p->error;
+ return p->u.calloc.ret;
+}
+
+void *failtest_malloc(size_t size, const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct malloc_call call;
+ call.size = size;
+
+ p = add_history(FAILTEST_MALLOC, file, line, &call);
+ if (should_fail(p)) {
+ p->u.calloc.ret = NULL;
+ p->error = ENOMEM;
+ } else {
+ p->u.calloc.ret = malloc(size);
+ }
+ errno = p->error;
+ return p->u.calloc.ret;
+}
+
+void *failtest_realloc(void *ptr, size_t size, const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct realloc_call call;
+ call.size = size;
+ p = add_history(FAILTEST_REALLOC, file, line, &call);
+
+ /* FIXME: Try one child moving allocation, one not. */
+ if (should_fail(p)) {
+ p->u.realloc.ret = NULL;
+ p->error = ENOMEM;
+ } else {
+ p->u.realloc.ret = realloc(ptr, size);
+ }
+ errno = p->error;
+ return p->u.realloc.ret;
+}
+
+int failtest_open(const char *pathname, int flags,
+ const char *file, unsigned line, ...)
+{
+ struct failtest_call *p;
+ struct open_call call;
+
+ call.pathname = strdup(pathname);
+ call.flags = flags;
+ if (flags & O_CREAT) {
+ va_list ap;
+ va_start(ap, line);
+ call.mode = va_arg(ap, mode_t);
+ va_end(ap);
+ }
+ p = add_history(FAILTEST_OPEN, file, line, &call);
+ if (should_fail(p)) {
+ p->u.open.ret = -1;
+ /* FIXME: Play with error codes? */
+ p->error = EACCES;
+ } else {
+ p->u.open.ret = open(pathname, flags, call.mode);
+ }
+ errno = p->error;
+ return p->u.open.ret;
+}
+
+int failtest_pipe(int pipefd[2], const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct pipe_call call;
+
+ p = add_history(FAILTEST_PIPE, file, line, &call);
+ if (should_fail(p)) {
+ p->u.open.ret = -1;
+ /* FIXME: Play with error codes? */
+ p->error = EMFILE;
+ } else {
+ p->u.pipe.ret = pipe(p->u.pipe.fds);
+ }
+ /* This causes valgrind to notice if they use pipefd[] after failure */
+ memcpy(pipefd, p->u.pipe.fds, sizeof(p->u.pipe.fds));
+ errno = p->error;
+ return p->u.pipe.ret;
+}
+
+ssize_t failtest_read(int fd, void *buf, size_t count,
+ const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct read_call call;
+ call.fd = fd;
+ call.buf = buf;
+ call.count = count;
+ p = add_history(FAILTEST_READ, file, line, &call);
+
+ /* This is going to change seek offset, so save it. */
+ if (control_fd != -1)
+ save_fd_orig(fd);
+
+ /* FIXME: Try partial read returns. */
+ if (should_fail(p)) {
+ p->u.read.ret = -1;
+ p->error = EIO;
+ } else {
+ p->u.read.ret = read(fd, buf, count);
+ }
+ errno = p->error;
+ return p->u.read.ret;
+}
+
+static struct write_info *new_write(void)
+{
+ writes = realloc(writes, (writes_num + 1) * sizeof(*writes));
+ return &writes[writes_num++];
+}
+
+ssize_t failtest_write(int fd, const void *buf, size_t count,
+ const char *file, unsigned line)
+{
+ struct failtest_call *p;
+ struct write_call call;
+ off_t offset;
+
+ call.fd = fd;
+ call.buf = buf;
+ call.count = count;
+ p = add_history(FAILTEST_WRITE, file, line, &call);
+
+ offset = lseek(fd, 0, SEEK_CUR);
+
+ /* If we're a child, save contents and tell parent about write. */
+ if (control_fd != -1) {
+ struct write_info *winfo = new_write();
+ enum info_type type = WRITE;
+
+ save_fd_orig(fd);
+
+ winfo->hdr.len = count;
+ winfo->hdr.fd = fd;
+ winfo->data = malloc(count);
+ memcpy(winfo->data, buf, count);
+ winfo->hdr.offset = offset;
+ if (winfo->hdr.offset != (off_t)-1) {
+ lseek(fd, offset, SEEK_SET);
+ winfo->olddata = malloc(count);
+ winfo->oldlen = read(fd, winfo->olddata, count);
+ if (winfo->oldlen == -1)
+ winfo->oldlen = 0;
+ }
+ write_all(control_fd, &type, sizeof(type));
+ write_all(control_fd, &winfo->hdr, sizeof(winfo->hdr));
+ write_all(control_fd, winfo->data, count);
+ }
+
+ /* FIXME: Try partial write returns. */
+ if (should_fail(p)) {
+ p->u.write.ret = -1;
+ p->error = EIO;
+ } else {
+ /* FIXME: We assume same write order in parent and child */
+ if (child_writes_num != 0) {
+ if (child_writes[0].hdr.fd != fd)
+ errx(1, "Child wrote to fd %u, not %u?",
+ child_writes[0].hdr.fd, fd);
+ if (child_writes[0].hdr.offset != offset)
+ errx(1, "Child wrote to offset %zu, not %zu?",
+ (size_t)child_writes[0].hdr.offset,
+ (size_t)offset);
+ if (child_writes[0].hdr.len != count)
+ errx(1, "Child wrote length %zu, not %zu?",
+ child_writes[0].hdr.len, count);
+ if (memcmp(child_writes[0].data, buf, count)) {
+ child_fail(NULL, 0,
+ "Child wrote differently to"
+ " fd %u than we did!\n", fd);
+ }
+ free(child_writes[0].data);
+ child_writes_num--;
+ memmove(&child_writes[0], &child_writes[1],
+ sizeof(child_writes[0]) * child_writes_num);
+
+ /* Is this is a socket or pipe, child wrote it
+ already. */
+ if (offset == (off_t)-1) {
+ p->u.write.ret = count;
+ errno = p->error;
+ return p->u.write.ret;
+ }
+ }
+ p->u.write.ret = write(fd, buf, count);
+ }
+ errno = p->error;
+ return p->u.write.ret;
+}
+
+/* We only trap this so we can dup fds in case we need to restore. */
+int failtest_close(int fd)
+{
+ unsigned int i;
+ int newfd = -1;
+
+ for (i = 0; i < fd_orig_num; i++) {
+ if (fd_orig[i].fd == fd) {
+ fd_orig[i].fd = newfd = dup(fd);
+ fd_orig[i].dupped = true;
+ }
+ }
+
+ for (i = 0; i < writes_num; i++) {
+ if (writes[i].hdr.fd == fd)
+ writes[i].hdr.fd = newfd;
+ }
+ return close(fd);
+}
+
+void failtest_init(int argc, char *argv[])
+{
+ if (argc == 2
+ && strncmp(argv[1], "--failpath=", strlen("--failpath=")) == 0) {
+ failpath = argv[1] + strlen("--failpath=");
+ }
+}
+
+void failtest_exit(int status)
+{
+ unsigned int i;
+
+ if (control_fd == -1)
+ exit(status);
+
+ if (failtest_exit_check) {
+ if (!failtest_exit_check(history, history_num))
+ child_fail(NULL, 0, "failtest_exit_check failed\n");
+ }
+
+ /* Restore any stuff we overwrote. */
+ for (i = 0; i < writes_num; i++) {
+ if (writes[i].hdr.offset == (off_t)-1)
+ continue;
+ if (writes[i].oldlen != 0) {
+ lseek(writes[i].hdr.fd, writes[i].hdr.offset,
+ SEEK_SET);
+ write(writes[i].hdr.fd, writes[i].olddata,
+ writes[i].oldlen);
+ }
+ }
+
+ /* Fix up fd offsets, restore sizes. */
+ for (i = 0; i < fd_orig_num; i++) {
+ lseek(fd_orig[i].fd, fd_orig[i].offset, SEEK_SET);
+ ftruncate(fd_orig[i].fd, fd_orig[i].size);
+ /* Free up any file descriptors we dup'ed. */
+ if (fd_orig[i].dupped)
+ close(fd_orig[i].fd);
+ }
+
+ tell_parent(SUCCESS);
+ exit(0);
+}
projects / ccan / commitdiff