X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Flib%2Flibudev-monitor.c;h=c87ff7434f48dcca56aa44b69c315fd25f3c922d;hp=a0f93546f7f8fb7c035c01f3ee03a49a3e88d26d;hb=19d7e87cc0ef364fb13a18411cb165b2427b3529;hpb=c7dff03e057a7548bc2f2adbd5d2798d209b56e6 diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c index a0f93546f..c87ff7434 100644 --- a/udev/lib/libudev-monitor.c +++ b/udev/lib/libudev-monitor.c @@ -56,11 +56,12 @@ struct udev_monitor_netlink_header { unsigned short properties_off; unsigned short properties_len; /* - * hashes of some common device propertie strings to filter with socket filters in + * hashes of some common device properties strings to filter with socket filters in * the client used in the kernel from socket filter rules; needs to be stored in * network order */ unsigned int filter_subsystem; + unsigned int filter_devtype; }; static struct udev_monitor *udev_monitor_new(struct udev *udev) @@ -222,7 +223,7 @@ static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i, (*i)++; } -static int filter_apply(struct udev_monitor *udev_monitor) +int udev_monitor_filter_update(struct udev_monitor *udev_monitor) { static struct sock_filter ins[256]; static struct sock_fprog filter; @@ -236,23 +237,34 @@ static int filter_apply(struct udev_monitor *udev_monitor) memset(ins, 0x00, sizeof(ins)); i = 0; - /* load magic in accu */ + /* load magic in A */ bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic)); /* jump if magic matches */ bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0); - /* wrong magic, drop packet */ - bpf_stmt(ins, &i, BPF_RET|BPF_K, 0); + /* wrong magic, pass packet */ + bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff); - /* load filter_subsystem value in accu */ - bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem)); /* add all subsystem match values */ udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) { - const char *subsys = udev_list_entry_get_name(list_entry); unsigned int hash; - hash = util_string_hash32(subsys); - /* jump if value does not match */ - bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); + /* load filter_subsystem value in A */ + bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem)); + hash = util_string_hash32(udev_list_entry_get_name(list_entry)); + if (udev_list_entry_get_value(list_entry) == NULL) { + /* jump if subsystem does not match */ + bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); + } else { + /* jump if subsystem does not match */ + bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3); + + /* load filter_devtype value in A */ + bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype)); + /* jump if value does not match */ + hash = util_string_hash32(udev_list_entry_get_value(list_entry)); + bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); + } + /* matched, pass packet */ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff); @@ -278,7 +290,7 @@ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor) err = bind(udev_monitor->sock, (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen); } else if (udev_monitor->snl.nl_family != 0) { - filter_apply(udev_monitor); + udev_monitor_filter_update(udev_monitor); err = bind(udev_monitor->sock, (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl)); } else { @@ -374,20 +386,29 @@ int udev_monitor_get_fd(struct udev_monitor *udev_monitor) static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device) { struct udev_list_entry *list_entry; - int pass = 0; if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL) return 1; udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) { - const char *subsys = udev_device_get_subsystem(udev_device); + const char *subsys = udev_list_entry_get_name(list_entry); + const char *dsubsys = udev_device_get_subsystem(udev_device); + const char *devtype; + const char *ddevtype; - if (strcmp(udev_list_entry_get_name(list_entry), subsys) == 0) { - pass= 1; - break; - } + if (strcmp(dsubsys, subsys) != 0) + continue; + + devtype = udev_list_entry_get_value(list_entry); + if (devtype == NULL) + return 1; + ddevtype = udev_device_get_devtype(udev_device); + if (ddevtype == NULL) + continue; + if (strcmp(ddevtype, devtype) == 0) + return 1; } - return pass; + return 0; } /** @@ -648,6 +669,9 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi nlh.magic = htonl(UDEV_MONITOR_MAGIC); val = udev_device_get_subsystem(udev_device); nlh.filter_subsystem = htonl(util_string_hash32(val)); + val = udev_device_get_devtype(udev_device); + if (val != NULL) + nlh.filter_devtype = htonl(util_string_hash32(val)); iov[0].iov_base = &nlh; iov[0].iov_len = sizeof(struct udev_monitor_netlink_header); @@ -672,14 +696,22 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi return count; } -int udev_monitor_filter_add_match_subsystem(struct udev_monitor *udev_monitor, const char *subsystem) +int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype) { if (udev_monitor == NULL) return -EINVAL; if (subsystem == NULL) return 0; if (udev_list_entry_add(udev_monitor->udev, - &udev_monitor->filter_subsystem_list, subsystem, NULL, 1, 0) == NULL) + &udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL) return -ENOMEM; return 0; } + +int udev_monitor_filter_remove(struct udev_monitor *udev_monitor) +{ + static struct sock_fprog filter = { 0, NULL }; + + udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list); + return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); +}