[libvirt] [PATCH v4 2/4] monitor: Enable adding an inherited fd to an fd set

qmp_add_fd() gets an fd that was received over a socket with SCM_RIGHTS and adds it to an fd set. This patch adds support that will enable adding an fd that was inherited on the command line to an fd set. Note: All of the code added to monitor_fdset_add_fd(), with the exception of the error path for non-valid fdset-id, is code motion from qmp_add_fd(). Signed-off-by: Corey Bryant <coreyb(a)linux.vnet.ibm.com&gt; Reviewed-by: Eric Blake <eblake(a)redhat.com&gt; --- v2: -Removed Error** parameter from monitor_fdset_add_fd() v3: -Added Error** parameter back to monitor_fdset_add_fd() -Move 'if (!mon_fdset_cur)' change to patch 1 (kwolf(a)redhat.com) -Move code that prevents removal of fd from fd set during init to it's own patch (eblake(a)redhat.com, kwolf(a)redhat.com) -Mention code motion in commit message (kwolf(a)redhat.com) v4: -Fix fd leak in qmp_add_fd() (kwolf(a)redhat.com) monitor.c | 157 ++++++++++++++++++++++++++++++++++---------------------------- monitor.h | 3 ++ 2 files changed, 88 insertions(+), 72 deletions(-) diff --git a/monitor.c b/monitor.c index 2e3248f..d8f66ca 100644 --- a/monitor.c +++ b/monitor.c @@ -2135,8 +2135,6 @@ AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, bool has_opaque, { int fd; Monitor *mon = cur_mon; - MonFdset *mon_fdset = NULL; - MonFdsetFd *mon_fdset_fd; AddfdInfo *fdinfo; fd = qemu_chr_fe_get_msgfd(mon->chr); @@ -2145,78 +2143,12 @@ AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, bool has_opaque, goto error; } - if (has_fdset_id) { - QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { - /* Break if match found or match impossible due to ordering by ID */ - if (fdset_id <= mon_fdset->id) { - if (fdset_id < mon_fdset->id) { - mon_fdset = NULL; - } - break; - } - } + fdinfo = monitor_fdset_add_fd(fd, has_fdset_id, fdset_id, + has_opaque, opaque, errp); + if (fdinfo) { + return fdinfo; } - if (mon_fdset == NULL) { - int64_t fdset_id_prev = -1; - MonFdset *mon_fdset_cur = QLIST_FIRST(&mon_fdsets); - - if (has_fdset_id) { - if (fdset_id < 0) { - error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id", - "a non-negative value"); - goto error; - } - /* Use specified fdset ID */ - QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { - mon_fdset_cur = mon_fdset; - if (fdset_id < mon_fdset_cur->id) { - break; - } - } - } else { - /* Use first available fdset ID */ - QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { - mon_fdset_cur = mon_fdset; - if (fdset_id_prev == mon_fdset_cur->id - 1) { - fdset_id_prev = mon_fdset_cur->id; - continue; - } - break; - } - } - - mon_fdset = g_malloc0(sizeof(*mon_fdset)); - if (has_fdset_id) { - mon_fdset->id = fdset_id; - } else { - mon_fdset->id = fdset_id_prev + 1; - } - - /* The fdset list is ordered by fdset ID */ - if (!mon_fdset_cur) { - QLIST_INSERT_HEAD(&mon_fdsets, mon_fdset, next); - } else if (mon_fdset->id < mon_fdset_cur->id) { - QLIST_INSERT_BEFORE(mon_fdset_cur, mon_fdset, next); - } else { - QLIST_INSERT_AFTER(mon_fdset_cur, mon_fdset, next); - } - } - - mon_fdset_fd = g_malloc0(sizeof(*mon_fdset_fd)); - mon_fdset_fd->fd = fd; - mon_fdset_fd->removed = false; - if (has_opaque) { - mon_fdset_fd->opaque = g_strdup(opaque); - } - QLIST_INSERT_HEAD(&mon_fdset->fds, mon_fdset_fd, next); - - fdinfo = g_malloc0(sizeof(*fdinfo)); - fdinfo->fdset_id = mon_fdset->id; - fdinfo->fd = mon_fdset_fd->fd; - - return fdinfo; - error: if (fd != -1) { close(fd); @@ -2301,6 +2233,87 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) return fdset_list; } +AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, + bool has_opaque, const char *opaque, + Error **errp) +{ + MonFdset *mon_fdset = NULL; + MonFdsetFd *mon_fdset_fd; + AddfdInfo *fdinfo; + + if (has_fdset_id) { + QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { + /* Break if match found or match impossible due to ordering by ID */ + if (fdset_id <= mon_fdset->id) { + if (fdset_id < mon_fdset->id) { + mon_fdset = NULL; + } + break; + } + } + } + + if (mon_fdset == NULL) { + int64_t fdset_id_prev = -1; + MonFdset *mon_fdset_cur = QLIST_FIRST(&mon_fdsets); + + if (has_fdset_id) { + if (fdset_id < 0) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id", + "a non-negative value"); + return NULL; + } + /* Use specified fdset ID */ + QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { + mon_fdset_cur = mon_fdset; + if (fdset_id < mon_fdset_cur->id) { + break; + } + } + } else { + /* Use first available fdset ID */ + QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { + mon_fdset_cur = mon_fdset; + if (fdset_id_prev == mon_fdset_cur->id - 1) { + fdset_id_prev = mon_fdset_cur->id; + continue; + } + break; + } + } + + mon_fdset = g_malloc0(sizeof(*mon_fdset)); + if (has_fdset_id) { + mon_fdset->id = fdset_id; + } else { + mon_fdset->id = fdset_id_prev + 1; + } + + /* The fdset list is ordered by fdset ID */ + if (!mon_fdset_cur) { + QLIST_INSERT_HEAD(&mon_fdsets, mon_fdset, next); + } else if (mon_fdset->id < mon_fdset_cur->id) { + QLIST_INSERT_BEFORE(mon_fdset_cur, mon_fdset, next); + } else { + QLIST_INSERT_AFTER(mon_fdset_cur, mon_fdset, next); + } + } + + mon_fdset_fd = g_malloc0(sizeof(*mon_fdset_fd)); + mon_fdset_fd->fd = fd; + mon_fdset_fd->removed = false; + if (has_opaque) { + mon_fdset_fd->opaque = g_strdup(opaque); + } + QLIST_INSERT_HEAD(&mon_fdset->fds, mon_fdset_fd, next); + + fdinfo = g_malloc0(sizeof(*fdinfo)); + fdinfo->fdset_id = mon_fdset->id; + fdinfo->fd = mon_fdset_fd->fd; + + return fdinfo; +} + int monitor_fdset_get_fd(int64_t fdset_id, int flags) { #ifndef _WIN32 diff --git a/monitor.h b/monitor.h index b6e7d95..d4c017e 100644 --- a/monitor.h +++ b/monitor.h @@ -90,6 +90,9 @@ int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret); int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret); +AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, + bool has_opaque, const char *opaque, + Error **errp); int monitor_fdset_get_fd(int64_t fdset_id, int flags); int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd); int monitor_fdset_dup_fd_remove(int dup_fd); -- 1.7.11.4