diff options
Diffstat (limited to 'support/export/v4clients.c')
| -rw-r--r-- | support/export/v4clients.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/support/export/v4clients.c b/support/export/v4clients.c new file mode 100644 index 0000000..3230251 --- /dev/null +++ b/support/export/v4clients.c @@ -0,0 +1,233 @@ +/* + * support/export/v4clients.c + * + * Montior clients appearing in, and disappearing from, /proc/fs/nfsd/clients + * and log relevant information. + */ + +#include <unistd.h> +#include <stdlib.h> +#include <sys/inotify.h> +#include <sys/stat.h> +#include <errno.h> +#include "export.h" + +/* search.h declares 'struct entry' and nfs_prot.h + * does too. Easiest fix is to trick search.h into + * calling its struct "struct Entry". + */ +#define entry Entry +#include <search.h> +#undef entry + +static int clients_fd = -1; + +void v4clients_init(void) +{ + struct stat sb; + + if (stat("/proc/fs/nfsd/clients", &sb) != 0 || + !S_ISDIR(sb.st_mode)) + return; + if (clients_fd >= 0) + return; + clients_fd = inotify_init1(IN_NONBLOCK); + if (clients_fd < 0) { + xlog_err("Unable to initialise v4clients watcher: %s\n", + strerror(errno)); + return; + } + if (inotify_add_watch(clients_fd, "/proc/fs/nfsd/clients", + IN_CREATE | IN_DELETE) < 0) { + xlog_err("Unable to watch /proc/fs/nfsd/clients: %s\n", + strerror(errno)); + close(clients_fd); + clients_fd = -1; + return; + } +} + +void v4clients_set_fds(fd_set *fdset) +{ + if (clients_fd >= 0) + FD_SET(clients_fd, fdset); +} + +static void *tree_root; +static int have_unconfirmed; + +struct ent { + unsigned long num; + char *clientid; + char *addr; + int vers; + int unconfirmed; + int wid; +}; + +static int ent_cmp(const void *av, const void *bv) +{ + const struct ent *a = av; + const struct ent *b = bv; + + if (a->num < b->num) + return -1; + if (a->num > b->num) + return 1; + return 0; +} + +static void free_ent(struct ent *ent) +{ + free(ent->clientid); + free(ent->addr); + free(ent); +} + +static char *dup_line(char *line) +{ + char *ret; + char *e = strchr(line, '\n'); + if (!e) + e = line + strlen(line); + ret = malloc(e - line + 1); + if (ret) { + memcpy(ret, line, e - line); + ret[e-line] = 0; + } + return ret; +} + +static void read_info(struct ent *key) +{ + char buf[2048]; + char *path; + int was_unconfirmed = key->unconfirmed; + FILE *f; + + if (asprintf(&path, "/proc/fs/nfsd/clients/%lu/info", key->num) < 0) + return; + + f = fopen(path, "r"); + if (!f) { + free(path); + return; + } + if (key->wid < 0) + key->wid = inotify_add_watch(clients_fd, path, IN_MODIFY); + + while (fgets(buf, sizeof(buf), f)) { + if (strncmp(buf, "clientid: ", 10) == 0) { + free(key->clientid); + key->clientid = dup_line(buf+10); + } + if (strncmp(buf, "address: ", 9) == 0) { + free(key->addr); + key->addr = dup_line(buf+9); + } + if (strncmp(buf, "minor version: ", 15) == 0) + key->vers = atoi(buf+15); + if (strncmp(buf, "status: ", 8) == 0 && + strstr(buf, " unconfirmed") != NULL) { + key->unconfirmed = 1; + have_unconfirmed = 1; + } + if (strncmp(buf, "status: ", 8) == 0 && + strstr(buf, " confirmed") != NULL) + key->unconfirmed = 0; + } + fclose(f); + free(path); + + if (was_unconfirmed && !key->unconfirmed) + xlog(L_NOTICE, "v4.%d client attached: %s from %s", + key->vers, key->clientid ?: "-none-", + key->addr ?: "-none-"); + if (!key->unconfirmed && key->wid >= 0) { + inotify_rm_watch(clients_fd, key->wid); + key->wid = -1; + } +} + +static void add_id(int id) +{ + struct ent **ent; + struct ent *key; + + key = calloc(1, sizeof(*key)); + if (!key) { + return; + } + key->num = id; + key->wid = -1; + + ent = tsearch(key, &tree_root, ent_cmp); + + if (!ent || *ent != key) + /* Already existed, or insertion failed */ + free_ent(key); + else + read_info(key); +} + +static void del_id(unsigned long id) +{ + struct ent key = {.num = id}; + struct ent **e, *ent; + + e = tfind(&key, &tree_root, ent_cmp); + if (!e || !*e) + return; + ent = *e; + tdelete(ent, &tree_root, ent_cmp); + if (!ent->unconfirmed) + xlog(L_NOTICE, "v4.%d client detached: %s from %s", + ent->vers, ent->clientid, ent->addr); + if (ent->wid >= 0) + inotify_rm_watch(clients_fd, ent->wid); + free_ent(ent); +} + +static void check_id(unsigned long id) +{ + struct ent key = {.num = id}; + struct ent **e, *ent; + + e = tfind(&key, &tree_root, ent_cmp); + if (!e || !*e) + return; + ent = *e; + if (ent->unconfirmed) + read_info(ent); +} + +int v4clients_process(fd_set *fdset) +{ + char buf[4096] __attribute__((aligned(__alignof__(struct inotify_event)))); + const struct inotify_event *ev; + ssize_t len; + char *ptr; + + if (clients_fd < 0 || + !FD_ISSET(clients_fd, fdset)) + return 0; + + while ((len = read(clients_fd, buf, sizeof(buf))) > 0) { + for (ptr = buf; ptr < buf + len; + ptr += sizeof(struct inotify_event) + ev->len) { + int id; + ev = (const struct inotify_event *)ptr; + + id = atoi(ev->name); + if (id <= 0) + continue; + if (ev->mask & IN_CREATE) + add_id(id); + if (ev->mask & IN_DELETE) + del_id(id); + if (ev->mask & IN_MODIFY) + check_id(id); + } + } + return 1; +} |