Signed-off-by: Andrew Gregory <[email protected]>
---
* split read/write sections into _alpm_chroot_{write_to_child,read_from_child}
* fully spell out parent2child/child2parent
* replaced pthread_sigmask with sigaction
* renamed p2c_cb and p2c_ctx -> stdin_cb and stdin_ctx and updated doxygen
* stdin_ctx was left as void* rather than alpm_list_t* because
void* is traditional for caller-supplied callback context
lib/libalpm/hook.c | 2 +-
lib/libalpm/trans.c | 2 +-
lib/libalpm/util.c | 199 +++++++++++++++++++++++++++++++++++++++++++++-------
lib/libalpm/util.h | 5 +-
4 files changed, 179 insertions(+), 29 deletions(-)
diff --git a/lib/libalpm/hook.c b/lib/libalpm/hook.c
index bff072d..6d238d8 100644
--- a/lib/libalpm/hook.c
+++ b/lib/libalpm/hook.c
@@ -512,7 +512,7 @@ static int _alpm_hook_run_hook(alpm_handle_t *handle,
struct _alpm_hook_t *hook)
}
}
- return _alpm_run_chroot(handle, hook->cmd[0], hook->cmd);
+ return _alpm_run_chroot(handle, hook->cmd[0], hook->cmd, NULL, NULL);
}
int _alpm_hook_run(alpm_handle_t *handle, enum _alpm_hook_when_t when)
diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
index a6b1aef..06997a0 100644
--- a/lib/libalpm/trans.c
+++ b/lib/libalpm/trans.c
@@ -391,7 +391,7 @@ int _alpm_runscriptlet(alpm_handle_t *handle, const char
*filepath,
_alpm_log(handle, ALPM_LOG_DEBUG, "executing \"%s\"\n", cmdline);
- retval = _alpm_run_chroot(handle, SCRIPTLET_SHELL, argv);
+ retval = _alpm_run_chroot(handle, SCRIPTLET_SHELL, argv, NULL, NULL);
cleanup:
if(scriptfn && unlink(scriptfn)) {
diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index 66a2742..948fd47 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -31,6 +31,7 @@
#include <limits.h>
#include <sys/wait.h>
#include <fnmatch.h>
+#include <poll.h>
/* libarchive */
#include <archive.h>
@@ -445,16 +446,119 @@ ssize_t _alpm_files_in_directory(alpm_handle_t *handle,
const char *path,
return files;
}
+static int _alpm_chroot_write_to_child(alpm_handle_t *handle, int fd,
+ char *buf, ssize_t *buf_size, ssize_t buf_limit,
+ _alpm_cb_io out_cb, void *cb_ctx)
+{
+ ssize_t nwrite;
+ struct sigaction newaction, oldaction;
+
+ if(*buf_size == 0) {
+ /* empty buffer, ask the callback for more */
+ if((*buf_size = out_cb(buf, buf_limit, cb_ctx)) == 0) {
+ /* no more to write, close the pipe */
+ return -1;
+ }
+ }
+
+ /* ignore SIGPIPE in case the pipe has been closed */
+ newaction.sa_handler = SIG_IGN;
+ sigemptyset(&newaction.sa_mask);
+ newaction.sa_flags = 0;
+ sigaction(SIGPIPE, &newaction, &oldaction);
+
+ nwrite = write(fd, buf, *buf_size);
+
+ /* restore previous SIGPIPE handler */
+ sigaction(SIGPIPE, &oldaction, NULL);
+
+ if(nwrite != -1) {
+ /* write was successful, remove the written data from the
buffer */
+ *buf_size -= nwrite;
+ memmove(buf, buf + nwrite, *buf_size);
+ } else if(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
+ /* nothing written, try again later */
+ } else {
+ _alpm_log(handle, ALPM_LOG_ERROR,
+ _("unable to write to pipe (%s)\n"),
strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+static void _alpm_chroot_process_output(alpm_handle_t *handle, const char
*line)
+{
+ alpm_event_scriptlet_info_t event = {
+ .type = ALPM_EVENT_SCRIPTLET_INFO,
+ .line = line
+ };
+ alpm_logaction(handle, "ALPM-SCRIPTLET", "%s", line);
+ EVENT(handle, &event);
+}
+
+static int _alpm_chroot_read_from_child(alpm_handle_t *handle, int fd,
+ char *buf, ssize_t *buf_size, ssize_t buf_limit)
+{
+ ssize_t space = buf_limit - *buf_size - 2; /* reserve 2 for "\n\0" */
+ ssize_t nread = read(fd, buf + *buf_size, space);
+ if(nread > 0) {
+ char *newline = memchr(buf + *buf_size, '\n', nread);
+ *buf_size += nread;
+ if(newline) {
+ while(newline) {
+ size_t linelen = newline - buf + 1;
+ char old = buf[linelen];
+ buf[linelen] = '\0';
+ _alpm_chroot_process_output(handle, buf);
+ buf[linelen] = old;
+
+ *buf_size -= linelen;
+ memmove(buf, buf + linelen, *buf_size);
+ newline = memchr(buf, '\n', *buf_size);
+ }
+ } else if(nread == space) {
+ /* we didn't read a full line, but we're out of space */
+ strcpy(buf + *buf_size, "\n");
+ _alpm_chroot_process_output(handle, buf);
+ *buf_size = 0;
+ }
+ } else if(nread == 0) {
+ /* end-of-file */
+ if(*buf_size) {
+ strcpy(buf + *buf_size, "\n");
+ _alpm_chroot_process_output(handle, buf);
+ }
+ return -1;
+ } else if(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
+ /* nothing read, try again */
+ } else {
+ /* read error */
+ if(*buf_size) {
+ strcpy(buf + *buf_size, "\n");
+ _alpm_chroot_process_output(handle, buf);
+ }
+ _alpm_log(handle, ALPM_LOG_ERROR,
+ _("unable to read from pipe (%s)\n"),
strerror(errno));
+ return -1;
+ }
+ return 0;
+}
+
/** Execute a command with arguments in a chroot.
* @param handle the context handle
* @param cmd command to execute
* @param argv arguments to pass to cmd
+ * @param stdin_cb callback to provide input to the chroot on stdin
+ * @param stdin_ctx context to be passed to @a stdin_cb
* @return 0 on success, 1 on error
*/
-int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const
argv[])
+int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const
argv[],
+ _alpm_cb_io stdin_cb, void *stdin_ctx)
{
pid_t pid;
- int pipefd[2], cwdfd;
+ int child2parent_pipefd[2], parent2child_pipefd[2];
+ int cwdfd;
int retval = 0;
/* save the cwd so we can restore it later */
@@ -476,7 +580,13 @@ int _alpm_run_chroot(alpm_handle_t *handle, const char
*cmd, char *const argv[])
/* Flush open fds before fork() to avoid cloning buffers */
fflush(NULL);
- if(pipe(pipefd) == -1) {
+ if(pipe(child2parent_pipefd) == -1) {
+ _alpm_log(handle, ALPM_LOG_ERROR, _("could not create pipe
(%s)\n"), strerror(errno));
+ retval = 1;
+ goto cleanup;
+ }
+
+ if(stdin_cb && pipe(parent2child_pipefd) == -1) {
_alpm_log(handle, ALPM_LOG_ERROR, _("could not create pipe
(%s)\n"), strerror(errno));
retval = 1;
goto cleanup;
@@ -495,10 +605,15 @@ int _alpm_run_chroot(alpm_handle_t *handle, const char
*cmd, char *const argv[])
close(0);
close(1);
close(2);
- while(dup2(pipefd[1], 1) == -1 && errno == EINTR);
- while(dup2(pipefd[1], 2) == -1 && errno == EINTR);
- close(pipefd[0]);
- close(pipefd[1]);
+ while(dup2(child2parent_pipefd[1], 1) == -1 && errno == EINTR);
+ while(dup2(child2parent_pipefd[1], 2) == -1 && errno == EINTR);
+ if(stdin_cb) {
+ while(dup2(parent2child_pipefd[0], 0) == -1 && errno ==
EINTR);
+ close(parent2child_pipefd[0]);
+ close(parent2child_pipefd[1]);
+ }
+ close(child2parent_pipefd[0]);
+ close(child2parent_pipefd[1]);
if(cwdfd >= 0) {
close(cwdfd);
}
@@ -521,27 +636,59 @@ int _alpm_run_chroot(alpm_handle_t *handle, const char
*cmd, char *const argv[])
} else {
/* this code runs for the parent only (wait on the child) */
int status;
- FILE *pipe_file;
-
- close(pipefd[1]);
- pipe_file = fdopen(pipefd[0], "r");
- if(pipe_file == NULL) {
- close(pipefd[0]);
- retval = 1;
+ char obuf[PIPE_BUF]; /* writes <= PIPE_BUF are guaranteed
atomic */
+ char ibuf[LINE_MAX];
+ ssize_t olen = 0, ilen = 0;
+ nfds_t nfds = 2;
+ struct pollfd fds[2], *child2parent = &(fds[0]), *parent2child
= &(fds[1]);
+
+ child2parent->fd = child2parent_pipefd[0];
+ child2parent->events = POLLIN;
+ fcntl(child2parent->fd, F_SETFL, O_NONBLOCK);
+ close(child2parent_pipefd[1]);
+
+ if(stdin_cb) {
+ parent2child->fd = parent2child_pipefd[1];
+ parent2child->events = POLLOUT;
+ fcntl(parent2child->fd, F_SETFL, O_NONBLOCK);
+ close(parent2child_pipefd[0]);
} else {
- while(!feof(pipe_file)) {
- char line[PATH_MAX];
- alpm_event_scriptlet_info_t event = {
- .type = ALPM_EVENT_SCRIPTLET_INFO,
- .line = line
- };
- if(safe_fgets(line, PATH_MAX, pipe_file) ==
NULL) {
- break;
+ parent2child->fd = -1;
+ parent2child->events = 0;
+ }
+
+#define STOP_POLLING(p) do { close(p->fd); p->fd = -1; } while(0)
+
+ while((child2parent->fd != -1 || parent2child->fd != -1)
+ && poll(fds, nfds, -1) > 0) {
+ if(child2parent->revents & POLLIN) {
+ if(_alpm_chroot_read_from_child(handle,
child2parent->fd,
+ ibuf, &ilen,
sizeof(ibuf)) != 0) {
+ /* we encountered end-of-file or an
error */
+ STOP_POLLING(child2parent);
}
- alpm_logaction(handle, "ALPM-SCRIPTLET", "%s",
line);
- EVENT(handle, &event);
+ } else if(child2parent->revents) {
+ /* anything but POLLIN indicates an error */
+ STOP_POLLING(child2parent);
}
- fclose(pipe_file);
+ if(parent2child->revents & POLLOUT) {
+ if(_alpm_chroot_write_to_child(handle,
parent2child->fd, obuf, &olen,
+ sizeof(obuf), stdin_cb,
stdin_ctx) != 0) {
+ STOP_POLLING(parent2child);
+ }
+ } else if(parent2child->revents) {
+ /* anything but POLLOUT indicates an error */
+ STOP_POLLING(parent2child);
+ }
+ }
+
+#undef STOP_POLLING
+
+ if(parent2child->fd != -1) {
+ close(parent2child->fd);
+ }
+ if(child2parent->fd != -1) {
+ close(child2parent->fd);
}
while(waitpid(pid, &status, 0) == -1) {
@@ -605,7 +752,7 @@ int _alpm_ldconfig(alpm_handle_t *handle)
char arg0[32];
char *argv[] = { arg0, NULL };
strcpy(arg0, "ldconfig");
- return _alpm_run_chroot(handle, LDCONFIG, argv);
+ return _alpm_run_chroot(handle, LDCONFIG, argv, NULL,
NULL);
}
}
diff --git a/lib/libalpm/util.h b/lib/libalpm/util.h
index 95112cf..c0c9ff0 100644
--- a/lib/libalpm/util.h
+++ b/lib/libalpm/util.h
@@ -119,7 +119,10 @@ int _alpm_unpack(alpm_handle_t *handle, const char
*archive, const char *prefix,
ssize_t _alpm_files_in_directory(alpm_handle_t *handle, const char *path, int
full_count);
-int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const
argv[]);
+typedef ssize_t (*_alpm_cb_io)(void *buf, ssize_t len, void *ctx);
+
+int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const
argv[],
+ _alpm_cb_io in_cb, void *in_ctx);
int _alpm_ldconfig(alpm_handle_t *handle);
int _alpm_str_cmp(const void *s1, const void *s2);
char *_alpm_filecache_find(alpm_handle_t *handle, const char *filename);
--
2.6.2
