init/parser.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <stddef.h>
#include <ctype.h>

#include "init.h"
#include "property_service.h"

#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>

static list_declare(service_list);
static list_declare(action_list);
static list_declare(action_queue);

#define RAW(x...) log_write(6, x)

void DUMP(void)
{
#if 0
    struct service *svc;
    struct action *act;
    struct command *cmd;
    struct listnode *node;
    struct listnode *node2;
    struct socketinfo *si;
    int n;
    
    list_for_each(node, &service_list) {
        svc = node_to_item(node, struct service, slist);
        RAW("service %s\n", svc->name);
        RAW("  class '%s'\n", svc->classname);
        RAW("  exec");
        for (n = 0; n < svc->nargs; n++) {
            RAW(" '%s'", svc->args[n]);
        }
        RAW("\n");
        for (si = svc->sockets; si; si = si->next) {
            RAW("  socket %s %s 0%o\n", si->name, si->type, si->perm);
        }
    }

    list_for_each(node, &action_list) {
        act = node_to_item(node, struct action, alist);
        RAW("on %s\n", act->name);
        list_for_each(node2, &act->commands) {
            cmd = node_to_item(node2, struct command, clist);
            RAW("  %p", cmd->func);
            for (n = 0; n < cmd->nargs; n++) {
                RAW(" %s", cmd->args[n]);
            }
            RAW("\n");
        }
        RAW("\n");
    }
#endif       
}

#define MAXARGS 64

#define T_EOF 0
#define T_TEXT 1
#define T_NEWLINE 2

struct parse_state
{
    char *ptr;
    char *text;
    int line;
    int nexttoken;
    void *context;
    void (*parse_line)(struct parse_state *state, int nargs, char **args);
    const char *filename;
};

static void *parse_service(struct parse_state *state, int nargs, char **args);
static void parse_line_service(struct parse_state *state, int nargs, char **args);

static void *parse_action(struct parse_state *state, int nargs, char **args);
static void parse_line_action(struct parse_state *state, int nargs, char **args);

void parse_error(struct parse_state *state, const char *fmt, ...)
{
    va_list ap;
    char buf[128];
    int off;
    
    snprintf(buf, 128, "%s: %d: ", state->filename, state->line);
    buf[127] = 0;
    off = strlen(buf);

    va_start(ap, fmt);
    vsnprintf(buf + off, 128 - off, fmt, ap);
    va_end(ap);
    buf[127] = 0;
    ERROR("%s", buf);
}

#define SECTION 0x01
#define COMMAND 0x02
#define OPTION  0x04

#include "keywords.h"

#define KEYWORD(symbol, flags, nargs, func) \
    [ K_##symbol ] = { #symbol, func, nargs + 1, flags, },

struct {
    const char *name;
    int (*func)(int nargs, char **args);
    unsigned char nargs;
    unsigned char flags;
} keyword_info[KEYWORD_COUNT] = {
    [ K_UNKNOWN ] = { "unknown", 0, 0, 0 },
#include "keywords.h"    
};
#undef KEYWORD

#define kw_is(kw, type) (keyword_info[kw].flags & (type))
#define kw_name(kw) (keyword_info[kw].name)
#define kw_func(kw) (keyword_info[kw].func)
#define kw_nargs(kw) (keyword_info[kw].nargs)

int lookup_keyword(const char *s)
{
    switch (*s++) {
    case 'c':
        if (!strcmp(s, "apability")) return K_capability;
        if (!strcmp(s, "lass")) return K_class;
        if (!strcmp(s, "lass_start")) return K_class_start;
        if (!strcmp(s, "lass_stop")) return K_class_stop;
        if (!strcmp(s, "onsole")) return K_console;
        if (!strcmp(s, "hown")) return K_chown;
        if (!strcmp(s, "hmod")) return K_chmod;
        if (!strcmp(s, "ritical")) return K_critical;
        break;
    case 'd':
        if (!strcmp(s, "isabled")) return K_disabled;
        if (!strcmp(s, "omainname")) return K_domainname;
        if (!strcmp(s, "evice")) return K_device;
        break;
    case 'e':
        if (!strcmp(s, "xec")) return K_exec;
        if (!strcmp(s, "xport")) return K_export;
        break;
    case 'g':
        if (!strcmp(s, "roup")) return K_group;
        break;
    case 'h':
        if (!strcmp(s, "ostname")) return K_hostname;
        break;
    case 'i':
        if (!strcmp(s, "fup")) return K_ifup;
        if (!strcmp(s, "nsmod")) return K_insmod;
        if (!strcmp(s, "mport")) return K_import;
        break;
    case 'l':
        if (!strcmp(s, "oglevel")) return K_loglevel;
        break;
    case 'm':
        if (!strcmp(s, "kdir")) return K_mkdir;
        if (!strcmp(s, "ount")) return K_mount;
        break;
    case 'o':
        if (!strcmp(s, "n")) return K_on;
        if (!strcmp(s, "neshot")) return K_oneshot;
        if (!strcmp(s, "nrestart")) return K_onrestart;
        break;
    case 'r':
        if (!strcmp(s, "estart")) return K_restart;
        break;
    case 's':
        if (!strcmp(s, "ervice")) return K_service;
        if (!strcmp(s, "etenv")) return K_setenv;
        if (!strcmp(s, "etkey")) return K_setkey;
        if (!strcmp(s, "etprop")) return K_setprop;
        if (!strcmp(s, "etrlimit")) return K_setrlimit;
        if (!strcmp(s, "ocket")) return K_socket;
        if (!strcmp(s, "tart")) return K_start;
        if (!strcmp(s, "top")) return K_stop;
        if (!strcmp(s, "ymlink")) return K_symlink;
        break;
    case 't':
        if (!strcmp(s, "rigger")) return K_trigger;
        break;
    case 'u':
        if (!strcmp(s, "ser")) return K_user;
        break;
    case 'w':
        if (!strcmp(s, "rite")) return K_write;
        break;
    }
    return K_UNKNOWN;
}

void parse_line_no_op(struct parse_state *state, int nargs, char **args)
{
}

int next_token(struct parse_state *state)
{
    char *x = state->ptr;
    char *s;

    if (state->nexttoken) {
        int t = state->nexttoken;
        state->nexttoken = 0;
        return t;
    }

    for (;;) {
        switch (*x) {
        case 0:
            state->ptr = x;
            return T_EOF;
        case '\n':
            state->line++;
            x++;
            state->ptr = x;
            return T_NEWLINE;
        case ' ':
        case '\t':
        case '\r':
            x++;
            continue;
        case '#':
            while (*x && (*x != '\n')) x++;
            state->line++;
            state->ptr = x;
            return T_NEWLINE;
        default:
            goto text;
        }
    }

textdone:
    state->ptr = x;
    *s = 0;
    return T_TEXT;
text:
    state->text = s = x;
textresume:
    for (;;) {
        switch (*x) {
        case 0:
            goto textdone;
        case ' ':
        case '\t':
        case '\r':
            x++;
            goto textdone;
        case '\n':
            state->nexttoken = T_NEWLINE;
            x++;
            goto textdone;
        case '"':
            x++;
            for (;;) {
                switch (*x) {
                case 0:
                        /* unterminated quoted thing */
                    state->ptr = x;
                    return T_EOF;
                case '"':
                    x++;
                    goto textresume;
                default:
                    *s++ = *x++;
                }
            }
            break;
        case '\\':
            x++;
            switch (*x) {
            case 0:
                goto textdone;
            case 'n':
                *s++ = '\n';
                break;
            case 'r':
                *s++ = '\r';
                break;
            case 't':
                *s++ = '\t';
                break;
            case '\\':
                *s++ = '\\';
                break;
            case '\r':
                    /* \ <cr> <lf> -> line continuation */
                if (x[1] != '\n') {
                    x++;
                    continue;
                }
            case '\n':
                    /* \ <lf> -> line continuation */
                state->line++;
                x++;
                    /* eat any extra whitespace */
                while((*x == ' ') || (*x == '\t')) x++;
                continue;
            default:
                    /* unknown escape -- just copy */
                *s++ = *x++;
            }
            continue;
        default:
            *s++ = *x++;
        }
    }
    return T_EOF;
}

void parse_line(int nargs, char **args)
{
    int n;
    int id = lookup_keyword(args[0]);
    printf("%s(%d)", args[0], id);
    for (n = 1; n < nargs; n++) {
        printf(" '%s'", args[n]);
    }
    printf("\n");
}

void parse_new_section(struct parse_state *state, int kw,
                       int nargs, char **args)
{
    printf("[ %s %s ]\n", args[0],
           nargs > 1 ? args[1] : "");
    switch(kw) {
    case K_service:
        state->context = parse_service(state, nargs, args);
        if (state->context) {
            state->parse_line = parse_line_service;
            return;
        }
        break;
    case K_on:
        state->context = parse_action(state, nargs, args);
        if (state->context) {
            state->parse_line = parse_line_action;
            return;
        }
        break;
    }
    state->parse_line = parse_line_no_op;
}

static void parse_config(const char *fn, char *s)
{
    struct parse_state state;
    char *args[MAXARGS];
    int nargs;

    nargs = 0;
    state.filename = fn;
    state.line = 1;
    state.ptr = s;
    state.nexttoken = 0;
    state.parse_line = parse_line_no_op;
    for (;;) {
        switch (next_token(&state)) {
        case T_EOF:
            state.parse_line(&state, 0, 0);
            return;
        case T_NEWLINE:
            if (nargs) {
                int kw = lookup_keyword(args[0]);
                if (kw_is(kw, SECTION)) {
                    state.parse_line(&state, 0, 0);
                    parse_new_section(&state, kw, nargs, args);
                } else {
                    state.parse_line(&state, nargs, args);
                }
                nargs = 0;
            }
            break;
        case T_TEXT:
            if (nargs < MAXARGS) {
                args[nargs++] = state.text;
            }
            break;
        }
    }
}

int parse_config_file(const char *fn)
{
    char *data;
    data = read_file(fn, 0);
    if (!data) return -1;

    parse_config(fn, data);
    DUMP();
    return 0;
}

static int valid_name(const char *name)
{
    if (strlen(name) > 16) {
        return 0;
    }
    while (*name) {
        if (!isalnum(*name) && (*name != '_') && (*name != '-')) {
            return 0;
        }
        name++;
    }
    return 1;
}

struct service *service_find_by_name(const char *name)
{
    struct listnode *node;
    struct service *svc;
    list_for_each(node, &service_list) {
        svc = node_to_item(node, struct service, slist);
        if (!strcmp(svc->name, name)) {
            return svc;
        }
    }
    return 0;
}

struct service *service_find_by_pid(pid_t pid)
{
    struct listnode *node;
    struct service *svc;
    list_for_each(node, &service_list) {
        svc = node_to_item(node, struct service, slist);
        if (svc->pid == pid) {
            return svc;
        }
    }
    return 0;
}

void service_for_each_class(const char *classname,
                            void (*func)(struct service *svc))
{
    struct listnode *node;
    struct service *svc;
    list_for_each(node, &service_list) {
        svc = node_to_item(node, struct service, slist);
        if (!strcmp(svc->classname, classname)) {
            func(svc);
        }
    }
}

void service_for_each_flags(unsigned matchflags,
                            void (*func)(struct service *svc))
{
    struct listnode *node;
    struct service *svc;
    list_for_each(node, &service_list) {
        svc = node_to_item(node, struct service, slist);
        if (svc->flags & matchflags) {
            func(svc);
        }
    }
}

void action_for_each_trigger(const char *trigger,
                             void (*func)(struct action *act))
{
    struct listnode *node;
    struct action *act;
    list_for_each(node, &action_list) {
        act = node_to_item(node, struct action, alist);
        if (!strcmp(act->name, trigger)) {
            func(act);
        }
    }
}

void queue_property_triggers(const char *name, const char *value)
{
    struct listnode *node;
    struct action *act;
    list_for_each(node, &action_list) {
        act = node_to_item(node, struct action, alist);
        if (!strncmp(act->name, "property:", strlen("property:"))) {
            const char *test = act->name + strlen("property:");
            int name_length = strlen(name);
            
            if (!strncmp(name, test, name_length) && 
                    test[name_length] == '=' &&
                    !strcmp(test + name_length + 1, value)) {
                action_add_queue_tail(act);
            }
        }
    }
}

void queue_all_property_triggers()
{
    struct listnode *node;
    struct action *act;
    list_for_each(node, &action_list) {
        act = node_to_item(node, struct action, alist);
        if (!strncmp(act->name, "property:", strlen("property:"))) {
            /* parse property name and value
               syntax is property:<name>=<value> */
            const char* name = act->name + strlen("property:");
            const char* equals = strchr(name, '=');
            if (equals) {
                char* prop_name[PROP_NAME_MAX + 1];
                const char* value;
                int length = equals - name;
                if (length > PROP_NAME_MAX) {
                    ERROR("property name too long in trigger %s", act->name);
                } else {
                    memcpy(prop_name, name, length);
                    prop_name[length] = 0;
                    
                    /* does the property exist, and match the trigger value? */
                    value = property_get((const char *)&prop_name[0]);
                    if (value && !strcmp(equals + 1, value)) {
                        action_add_queue_tail(act);
                    }
                }
            }
        }
    }
}

void action_add_queue_tail(struct action *act)
{
    list_add_tail(&action_queue, &act->qlist);
}

struct action *action_remove_queue_head(void)
{
    if (list_empty(&action_queue)) {
        return 0;
    } else {
        struct listnode *node = list_head(&action_queue);
        struct action *act = node_to_item(node, struct action, qlist);
        list_remove(node);
        return act;
    }
}

static void *parse_service(struct parse_state *state, int nargs, char **args)
{
    struct service *svc;
    if (nargs < 3) {
        parse_error(state, "services must have a name and a program\n");
        return 0;
    }
    if (!valid_name(args[1])) {
        parse_error(state, "invalid service name '%s'\n", args[1]);
        return 0;
    }

    svc = service_find_by_name(args[1]);
    if (svc) {
        parse_error(state, "ignored duplicate definition of service '%s'\n", args[1]);
        return 0;
    }
    
    nargs -= 2;
    svc = calloc(1, sizeof(*svc) + sizeof(char*) * nargs);
    if (!svc) {
        parse_error(state, "out of memory\n");
        return 0;
    }
    svc->name = args[1];
    svc->classname = "default";
    memcpy(svc->args, args + 2, sizeof(char*) * nargs);
    svc->args[nargs] = 0;
    svc->nargs = nargs;
    svc->onrestart.name = "onrestart";
    list_init(&svc->onrestart.commands);
    list_add_tail(&service_list, &svc->slist);
    return svc;
}

static void parse_line_service(struct parse_state *state, int nargs, char **args)
{
    struct service *svc = state->context;
    struct command *cmd;
    int kw, kw_nargs;

    if (nargs == 0) {
        return;
    }
    
    kw = lookup_keyword(args[0]);
    switch (kw) {
    case K_capability:
        break;
    case K_class:
        if (nargs != 2) {
            parse_error(state, "class option requires a classname\n");
        } else {
            svc->classname = args[1];
        }
        break;
    case K_console:
        svc->flags |= SVC_CONSOLE;
        break;
    case K_disabled:
        svc->flags |= SVC_DISABLED;
        break;
    case K_group:
        if (nargs < 2) {
            parse_error(state, "group option requires a group id\n");
        } else if (nargs > NR_SVC_SUPP_GIDS + 2) {
            parse_error(state, "group option accepts at most %d supp. groups\n",
                        NR_SVC_SUPP_GIDS);
        } else {
            int n;
            svc->gid = decode_uid(args[1]);
            for (n = 2; n < nargs; n++) {
                svc->supp_gids[n-2] = decode_uid(args[n]);
            }
            svc->nr_supp_gids = n - 2;
        }
        break;
    case K_oneshot:
        svc->flags |= SVC_ONESHOT;
        break;
    case K_onrestart:
        nargs--;
        args++;
        kw = lookup_keyword(args[0]);
        if (!kw_is(kw, COMMAND)) {
            parse_error(state, "invalid command '%s'\n", args[0]);
            break;
        }
        kw_nargs = kw_nargs(kw);
        if (nargs < kw_nargs) {
            parse_error(state, "%s requires %d %s\n", args[0], kw_nargs - 1,
                kw_nargs > 2 ? "arguments" : "argument");
            break;
        }

        cmd = malloc(sizeof(*cmd) + sizeof(char*) * nargs);
        cmd->func = kw_func(kw);
        cmd->nargs = nargs;
        memcpy(cmd->args, args, sizeof(char*) * nargs);
        list_add_tail(&svc->onrestart.commands, &cmd->clist);
        break;
    case K_critical:
        svc->flags |= SVC_CRITICAL;
        break;
    case K_setenv: { /* name value */
        struct svcenvinfo *ei;
        if (nargs < 2) {
            parse_error(state, "setenv option requires name and value arguments\n");
            break;
        }
        ei = calloc(1, sizeof(*ei));
        if (!ei) {
            parse_error(state, "out of memory\n");
            break;
        }
        ei->name = args[1];
        ei->value = args[2];
        ei->next = svc->envvars;
        svc->envvars = ei;
        break;
    }
    case K_socket: {/* name type perm [ uid gid ] */
        struct socketinfo *si;
        if (nargs < 4) {
            parse_error(state, "socket option requires name, type, perm arguments\n");
            break;
        }
        if (strcmp(args[2],"dgram") && strcmp(args[2],"stream")) {
            parse_error(state, "socket type must be 'dgram' or 'stream'\n");
            break;
        }
        si = calloc(1, sizeof(*si));
        if (!si) {
            parse_error(state, "out of memory\n");
            break;
        }
        si->name = args[1];
        si->type = args[2];
        si->perm = strtoul(args[3], 0, 8);
        if (nargs > 4)
            si->uid = decode_uid(args[4]);
        if (nargs > 5)
            si->gid = decode_uid(args[5]);
        si->next = svc->sockets;
        svc->sockets = si;
        break;
    }
    case K_user:
        if (nargs != 2) {
            parse_error(state, "user option requires a user id\n");
        } else {
            svc->uid = decode_uid(args[1]);
        }
        break;
    default:
        parse_error(state, "invalid option '%s'\n", args[0]);
    }
}

static void *parse_action(struct parse_state *state, int nargs, char **args)
{
    struct action *act;
    if (nargs < 2) {
        parse_error(state, "actions must have a trigger\n");
        return 0;
    }
    if (nargs > 2) {
        parse_error(state, "actions may not have extra parameters\n");
        return 0;
    }
    act = calloc(1, sizeof(*act));
    act->name = args[1];
    list_init(&act->commands);
    list_add_tail(&action_list, &act->alist);
        /* XXX add to hash */
    return act;
}

static void parse_line_action(struct parse_state* state, int nargs, char **args)
{
    struct command *cmd;
    struct action *act = state->context;
    int (*func)(int nargs, char **args);
    int kw, n;

    if (nargs == 0) {
        return;
    }

    kw = lookup_keyword(args[0]);
    if (!kw_is(kw, COMMAND)) {
        parse_error(state, "invalid command '%s'\n", args[0]);
        return;
    }

    n = kw_nargs(kw);
    if (nargs < n) {
        parse_error(state, "%s requires %d %s\n", args[0], n - 1,
            n > 2 ? "arguments" : "argument");
        return;
    }
    cmd = malloc(sizeof(*cmd) + sizeof(char*) * nargs);
    cmd->func = kw_func(kw);
    cmd->nargs = nargs;
    memcpy(cmd->args, args, sizeof(char*) * nargs);
    list_add_tail(&act->commands, &cmd->clist);
}