diff options
Diffstat (limited to 'lib/unixctl.c')
| -rw-r--r-- | lib/unixctl.c | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/lib/unixctl.c b/lib/unixctl.c new file mode 100644 index 00000000..42b6eeff --- /dev/null +++ b/lib/unixctl.c @@ -0,0 +1,592 @@ +/* + * Copyright (c) 2008, 2009 Nicira Networks. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <config.h> +#include "unixctl.h" +#include <assert.h> +#include <ctype.h> +#include <errno.h> +#include <poll.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <unistd.h> +#include "coverage.h" +#include "dirs.h" +#include "dynamic-string.h" +#include "fatal-signal.h" +#include "list.h" +#include "ofpbuf.h" +#include "poll-loop.h" +#include "shash.h" +#include "socket-util.h" +#include "util.h" + +#ifndef SCM_CREDENTIALS +#include <time.h> +#endif + +#define THIS_MODULE VLM_unixctl +#include "vlog.h" + +struct unixctl_command { + void (*cb)(struct unixctl_conn *, const char *args); +}; + +struct unixctl_conn { + struct list node; + int fd; + + enum { S_RECV, S_PROCESS, S_SEND } state; + struct ofpbuf in; + struct ds out; + size_t out_pos; +}; + +/* Server for control connection. */ +struct unixctl_server { + char *path; + int fd; + struct list conns; +}; + +/* Client for control connection. */ +struct unixctl_client { + char *connect_path; + char *bind_path; + FILE *stream; +}; + +static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5); + +static struct shash commands = SHASH_INITIALIZER(&commands); + +static void +unixctl_help(struct unixctl_conn *conn, const char *args UNUSED) +{ + struct ds ds = DS_EMPTY_INITIALIZER; + struct shash_node *node; + + ds_put_cstr(&ds, "The available commands are:\n"); + HMAP_FOR_EACH (node, struct shash_node, node, &commands.map) { + ds_put_format(&ds, "\t%s\n", node->name); + } + unixctl_command_reply(conn, 214, ds_cstr(&ds)); + ds_destroy(&ds); +} + +void +unixctl_command_register(const char *name, + void (*cb)(struct unixctl_conn *, const char *args)) +{ + struct unixctl_command *command; + + assert(!shash_find_data(&commands, name) + || shash_find_data(&commands, name) == cb); + command = xmalloc(sizeof *command); + command->cb = cb; + shash_add(&commands, name, command); +} + +static const char * +translate_reply_code(int code) +{ + switch (code) { + case 200: return "OK"; + case 201: return "Created"; + case 202: return "Accepted"; + case 204: return "No Content"; + case 211: return "System Status"; + case 214: return "Help"; + case 400: return "Bad Request"; + case 401: return "Unauthorized"; + case 403: return "Forbidden"; + case 404: return "Not Found"; + case 500: return "Internal Server Error"; + case 501: return "Invalid Argument"; + case 503: return "Service Unavailable"; + default: return "Unknown"; + } +} + +void +unixctl_command_reply(struct unixctl_conn *conn, + int code, const char *body) +{ + struct ds *out = &conn->out; + + COVERAGE_INC(unixctl_replied); + assert(conn->state == S_PROCESS); + conn->state = S_SEND; + conn->out_pos = 0; + + ds_clear(out); + ds_put_format(out, "%03d %s\n", code, translate_reply_code(code)); + if (body) { + const char *p; + for (p = body; *p != '\0'; ) { + size_t n = strcspn(p, "\n"); + + if (*p == '.') { + ds_put_char(out, '.'); + } + ds_put_buffer(out, p, n); + ds_put_char(out, '\n'); + p += n; + if (*p == '\n') { + p++; + } + } + } + ds_put_cstr(out, ".\n"); +} + +/* Creates a unixctl server listening on 'path', which may be: + * + * - NULL, in which case <rundir>/<program>.<pid>.ctl is used. + * + * - A name that does not start with '/', in which case it is put in + * <rundir>. + * + * - An absolute path (starting with '/') that gives the exact name of + * the Unix domain socket to listen on. + * + * A program that (optionally) daemonizes itself should call this function + * *after* daemonization, so that the socket name contains the pid of the + * daemon instead of the pid of the program that exited. (Otherwise, + * "ovs-appctl --target <program>.pid" will fail.) + * + * Returns 0 if successful, otherwise a positive errno value. If successful, + * sets '*serverp' to the new unixctl_server, otherwise to NULL. */ +int +unixctl_server_create(const char *path, struct unixctl_server **serverp) +{ + struct unixctl_server *server; + int error; + + unixctl_command_register("help", unixctl_help); + + server = xmalloc(sizeof *server); + list_init(&server->conns); + + if (path) { + if (path[0] == '/') { + server->path = xstrdup(path); + } else { + server->path = xasprintf("%s/%s", ovs_rundir, path); + } + } else { + server->path = xasprintf("%s/%s.%ld.ctl", ovs_rundir, + program_name, (long int) getpid()); + } + + server->fd = make_unix_socket(SOCK_STREAM, true, false, server->path, + NULL); + if (server->fd < 0) { + error = -server->fd; + fprintf(stderr, "Could not initialize control socket %s (%s)\n", + server->path, strerror(error)); + goto error; + } + + if (chmod(server->path, S_IRUSR | S_IWUSR) < 0) { + error = errno; + fprintf(stderr, "Failed to chmod control socket %s (%s)\n", + server->path, strerror(error)); + goto error; + } + + if (listen(server->fd, 10) < 0) { + error = errno; + fprintf(stderr, "Failed to listen on control socket %s (%s)\n", + server->path, strerror(error)); + goto error; + } + + *serverp = server; + return 0; + +error: + if (server->fd >= 0) { + close(server->fd); + } + free(server->path); + free(server); + *serverp = NULL; + return error; +} + +static void +new_connection(struct unixctl_server *server, int fd) +{ + struct unixctl_conn *conn; + + set_nonblocking(fd); + + conn = xmalloc(sizeof *conn); + list_push_back(&server->conns, &conn->node); + conn->fd = fd; + conn->state = S_RECV; + ofpbuf_init(&conn->in, 128); + ds_init(&conn->out); + conn->out_pos = 0; +} + +static int +run_connection_output(struct unixctl_conn *conn) +{ + while (conn->out_pos < conn->out.length) { + size_t bytes_written; + int error; + + error = write_fully(conn->fd, conn->out.string + conn->out_pos, + conn->out.length - conn->out_pos, &bytes_written); + conn->out_pos += bytes_written; + if (error) { + return error; + } + } + conn->state = S_RECV; + return 0; +} + +static void +process_command(struct unixctl_conn *conn, char *s) +{ + struct unixctl_command *command; + size_t name_len; + char *name, *args; + + COVERAGE_INC(unixctl_received); + conn->state = S_PROCESS; + + name = s; + name_len = strcspn(name, " "); + args = name + name_len; + args += strspn(args, " "); + name[name_len] = '\0'; + + command = shash_find_data(&commands, name); + if (command) { + command->cb(conn, args); + } else { + char *msg = xasprintf("\"%s\" is not a valid command", name); + unixctl_command_reply(conn, 400, msg); + free(msg); + } +} + +static int +run_connection_input(struct unixctl_conn *conn) +{ + for (;;) { + size_t bytes_read; + char *newline; + int error; + + newline = memchr(conn->in.data, '\n', conn->in.size); + if (newline) { + char *command = conn->in.data; + size_t n = newline - command + 1; + + if (n > 0 && newline[-1] == '\r') { + newline--; + } + *newline = '\0'; + + process_command(conn, command); + + ofpbuf_pull(&conn->in, n); + if (!conn->in.size) { + ofpbuf_clear(&conn->in); + } + return 0; + } + + ofpbuf_prealloc_tailroom(&conn->in, 128); + error = read_fully(conn->fd, ofpbuf_tail(&conn->in), + ofpbuf_tailroom(&conn->in), &bytes_read); + conn->in.size += bytes_read; + if (conn->in.size > 65536) { + VLOG_WARN_RL(&rl, "excess command length, killing connection"); + return EPROTO; + } + if (error) { + if (error == EAGAIN || error == EWOULDBLOCK) { + if (!bytes_read) { + return EAGAIN; + } + } else { + if (error != EOF || conn->in.size != 0) { + VLOG_WARN_RL(&rl, "read failed: %s", + (error == EOF + ? "connection dropped mid-command" + : strerror(error))); + } + return error; + } + } + } +} + +static int +run_connection(struct unixctl_conn *conn) +{ + int old_state; + do { + int error; + + old_state = conn->state; + switch (conn->state) { + case S_RECV: + error = run_connection_input(conn); + break; + + case S_PROCESS: + error = 0; + break; + + case S_SEND: + error = run_connection_output(conn); + break; + + default: + NOT_REACHED(); + } + if (error) { + return error; + } + } while (conn->state != old_state); + return 0; +} + +static void +kill_connection(struct unixctl_conn *conn) +{ + list_remove(&conn->node); + ofpbuf_uninit(&conn->in); + ds_destroy(&conn->out); + close(conn->fd); + free(conn); +} + +void +unixctl_server_run(struct unixctl_server *server) +{ + struct unixctl_conn *conn, *next; + int i; + + for (i = 0; i < 10; i++) { + int fd = accept(server->fd, NULL, NULL); + if (fd < 0) { + if (errno != EAGAIN && errno != EWOULDBLOCK) { + VLOG_WARN_RL(&rl, "accept failed: %s", strerror(errno)); + } + break; + } + new_connection(server, fd); + } + + LIST_FOR_EACH_SAFE (conn, next, + struct unixctl_conn, node, &server->conns) { + int error = run_connection(conn); + if (error && error != EAGAIN) { + kill_connection(conn); + } + } +} + +void +unixctl_server_wait(struct unixctl_server *server) +{ + struct unixctl_conn *conn; + + poll_fd_wait(server->fd, POLLIN); + LIST_FOR_EACH (conn, struct unixctl_conn, node, &server->conns) { + if (conn->state == S_RECV) { + poll_fd_wait(conn->fd, POLLIN); + } else if (conn->state == S_SEND) { + poll_fd_wait(conn->fd, POLLOUT); + } + } +} + +/* Destroys 'server' and stops listening for connections. */ +void +unixctl_server_destroy(struct unixctl_server *server) +{ + if (server) { + struct unixctl_conn *conn, *next; + + LIST_FOR_EACH_SAFE (conn, next, + struct unixctl_conn, node, &server->conns) { + kill_connection(conn); + } + + close(server->fd); + unlink(server->path); + fatal_signal_remove_file_to_unlink(server->path); + free(server->path); + free(server); + } +} + +/* Connects to a Vlog server socket. 'path' should be the name of a Vlog + * server socket. If it does not start with '/', it will be prefixed with + * ovs_rundir (e.g. /var/run). + * + * Returns 0 if successful, otherwise a positive errno value. If successful, + * sets '*clientp' to the new unixctl_client, otherwise to NULL. */ +int +unixctl_client_create(const char *path, struct unixctl_client **clientp) +{ + static int counter; + struct unixctl_client *client; + int error; + int fd = -1; + + /* Determine location. */ + client = xmalloc(sizeof *client); + if (path[0] == '/') { + client->connect_path = xstrdup(path); + } else { + client->connect_path = xasprintf("%s/%s", ovs_rundir, path); + } + client->bind_path = xasprintf("/tmp/vlog.%ld.%d", + (long int) getpid(), counter++); + + /* Open socket. */ + fd = make_unix_socket(SOCK_STREAM, false, false, + client->bind_path, client->connect_path); + if (fd < 0) { + error = -fd; + goto error; + } + + /* Bind socket to stream. */ + client->stream = fdopen(fd, "r+"); + if (!client->stream) { + error = errno; + VLOG_WARN("%s: fdopen failed (%s)", + client->connect_path, strerror(error)); + goto error; + } + *clientp = client; + return 0; + +error: + if (fd >= 0) { + close(fd); + } + free(client->connect_path); + free(client->bind_path); + free(client); + *clientp = NULL; + return error; +} + +/* Destroys 'client'. */ +void +unixctl_client_destroy(struct unixctl_client *client) +{ + if (client) { + unlink(client->bind_path); + fatal_signal_remove_file_to_unlink(client->bind_path); + free(client->bind_path); + free(client->connect_path); + fclose(client->stream); + free(client); + } +} + +/* Sends 'request' to the server socket and waits for a reply. Returns 0 if + * successful, otherwise to a positive errno value. If successful, sets + * '*reply' to the reply, which the caller must free, otherwise to NULL. */ +int +unixctl_client_transact(struct unixctl_client *client, + const char *request, + int *reply_code, char **reply_body) +{ + struct ds line = DS_EMPTY_INITIALIZER; + struct ds reply = DS_EMPTY_INITIALIZER; + int error; + + /* Send 'request' to server. Add a new-line if 'request' didn't end in + * one. */ + fputs(request, client->stream); + if (request[0] == '\0' || request[strlen(request) - 1] != '\n') { + putc('\n', client->stream); + } + if (ferror(client->stream)) { + VLOG_WARN("error sending request to %s: %s", + client->connect_path, strerror(errno)); + return errno; + } + + /* Wait for response. */ + *reply_code = -1; + for (;;) { + const char *s; + + error = ds_get_line(&line, client->stream); + if (error) { + VLOG_WARN("error reading reply from %s: %s", + client->connect_path, + (error == EOF ? "unexpected end of file" + : strerror(error))); + goto error; + } + + s = ds_cstr(&line); + if (*reply_code == -1) { + if (!isdigit(s[0]) || !isdigit(s[1]) || !isdigit(s[2])) { + VLOG_WARN("reply from %s does not start with 3-digit code", + client->connect_path); + error = EPROTO; + goto error; + } + sscanf(s, "%3d", reply_code); + } else { + if (s[0] == '.') { + if (s[1] == '\0') { + break; + } + s++; + } + ds_put_cstr(&reply, s); + ds_put_char(&reply, '\n'); + } + } + *reply_body = ds_cstr(&reply); + ds_destroy(&line); + return 0; + +error: + ds_destroy(&line); + ds_destroy(&reply); + *reply_code = 0; + *reply_body = NULL; + return error == EOF ? EPROTO : error; +} + +/* Returns the path of the server socket to which 'client' is connected. The + * caller must not modify or free the returned string. */ +const char * +unixctl_client_target(const struct unixctl_client *client) +{ + return client->connect_path; +} |