webdiss/src/cmd.c

#include "cmd.h"
#include "conf.h"
#include "acl.h"
#include "client.h"
#include "pool.h"
#include "worker.h"
#include "http.h"
#include "server.h"

#include "formats/json.h"
#include "formats/raw.h"
#ifdef MSGPACK
#include "formats/msgpack.h"
#endif
#include "formats/custom-type.h"

#include <stdlib.h>
#include <string.h>
#include <hiredis/hiredis.h>
#include <hiredis/async.h>
#include <ctype.h>

struct cmd *
cmd_new(struct http_client *client, int count) {

	struct cmd *c = calloc(1, sizeof(struct cmd));

	c->count = count;
	c->http_client = client;

	c->argv = calloc(count, sizeof(char*));
	c->argv_len = calloc(count, sizeof(size_t));

	return c;
}

void
cmd_free_argv(struct cmd *c) {

	int i;
	for(i = 0; i < c->count; ++i) {
		free((char*)c->argv[i]);
	}

	free(c->argv);
	free(c->argv_len);
}

void
cmd_free(struct cmd *c) {

	if(!c) return;

	free(c->jsonp);
	free(c->separator);
	free(c->if_none_match);
	if(c->mime_free) free(c->mime);

	if (c->ac && /* we have a connection */
		(c->database != c->w->s->cfg->database /* custom DB */
		|| cmd_is_subscribe(c))) {
		pool_free_context(c->ac);
	}

	cmd_free_argv(c);

	free(c);
}

/* taken from libevent */
static char *
decode_uri(const char *uri, size_t length, size_t *out_len, int always_decode_plus) {
	char c;
	size_t i, j;
	int in_query = always_decode_plus;

	char *ret = malloc(length);

	for (i = j = 0; i < length; i++) {
		c = uri[i];
		if (c == '?') {
			in_query = 1;
		} else if (c == '+' && in_query) {
			c = ' ';
		} else if (c == '%' && isxdigit((unsigned char)uri[i+1]) &&
		    isxdigit((unsigned char)uri[i+2])) {
			char tmp[] = { uri[i+1], uri[i+2], '\0' };
			c = (char)strtol(tmp, NULL, 16);
			i += 2;
		}
		ret[j++] = c;
	}
	*out_len = (size_t)j;

	return ret;
}

/* setup headers */
void
cmd_setup(struct cmd *cmd, struct http_client *client) {

	int i;
	cmd->keep_alive = client->keep_alive;
	cmd->w = client->w; /* keep track of the worker */

	for(i = 0; i < client->header_count; ++i) {
		if(strcasecmp(client->headers[i].key, "If-None-Match") == 0) {
			cmd->if_none_match = calloc(1+client->headers[i].val_sz, 1);
			memcpy(cmd->if_none_match, client->headers[i].val,
					client->headers[i].val_sz);
		} else if(strcasecmp(client->headers[i].key, "Connection") == 0 &&
				strcasecmp(client->headers[i].val, "Keep-Alive") == 0) {
			cmd->keep_alive = 1;
		}
	}

	if(client->type) {	/* transfer pointer ownership */
		cmd->mime = client->type;
		cmd->mime_free = 1;
		client->type = NULL;
	}

	if(client->jsonp) {	/* transfer pointer ownership */
		cmd->jsonp = client->jsonp;
		client->jsonp = NULL;
	}

	if(client->separator) {	/* transfer pointer ownership */
		cmd->separator = client->separator;
		client->separator = NULL;
	}

	if(client->filename) {	/* transfer pointer ownership */
		cmd->filename = client->filename;
		client->filename = NULL;
	}

	cmd->fd = client->fd;
	cmd->http_version = client->http_version;
}


cmd_response_t
cmd_run(struct worker *w, struct http_client *client,
		const char *uri, size_t uri_len,
		const char *body, size_t body_len) {

	char *qmark = memchr(uri, '?', uri_len);
	char *slash;
	const char *p, *cmd_name = uri;
	int cmd_len;
	int param_count = 0, cur_param = 1;

	struct cmd *cmd;
	formatting_fun f_format;

	/* count arguments */
	if(qmark) {
		uri_len = qmark - uri;
	}
	for(p = uri; p && p < uri + uri_len; param_count++) {
		p = memchr(p+1, '/', uri_len - (p+1-uri));
	}

	if(body && body_len) { /* PUT request */
		param_count++;
	}
	if(param_count == 0) {
		return CMD_PARAM_ERROR;
	}

	cmd = cmd_new(client, param_count);
	cmd->fd = client->fd;
	cmd->database = w->s->cfg->database;

	/* get output formatting function */
	uri_len = cmd_select_format(client, cmd, uri, uri_len, &f_format);

	/* add HTTP info */
	cmd_setup(cmd, client);

	/* check if we only have one command or more. */
	slash = memchr(uri, '/', uri_len);
	if(slash) {

		/* detect DB number by checking if first arg is only numbers */
		int has_db = 1;
		int db_num = 0;
		for(p = uri; p < slash; ++p) {
			if(*p < '0' || *p > '9') {
				has_db = 0;
				break;
			}
			db_num = db_num * 10 + (*p - '0');
		}

		/* shift to next arg if a db was set up */
		if(has_db) {
			char *next;
			cmd->database = db_num;
			cmd->count--; /* overcounted earlier */
			cmd_name = slash + 1;

			if((next = memchr(cmd_name, '/', uri_len - (slash - uri)))) {
				cmd_len = next - cmd_name;
			} else {
				cmd_len = uri_len - (slash - uri + 1);
			}
		} else {
			cmd_len = slash - uri;
		}
	} else {
		cmd_len = uri_len;
	}

	/* there is always a first parameter, it's the command name */
	cmd->argv[0] = malloc(cmd_len);
	memcpy(cmd->argv[0], cmd_name, cmd_len);
	cmd->argv_len[0] = cmd_len;

	/* check that the client is able to run this command */
	if(!acl_allow_command(cmd, w->s->cfg, client)) {
		cmd_free(cmd);
		return CMD_ACL_FAIL;
	}

	if(cmd_is_subscribe(cmd)) {
		/* create a new connection to Redis */
		cmd->ac = (redisAsyncContext*)pool_connect(w->pool, cmd->database, 0);

		/* register with the client, used upon disconnection */
		client->self_cmd = cmd;
		cmd->pub_sub_client = client;
	} else if(cmd->database != w->s->cfg->database) {
		/* create a new connection to Redis for custom DBs */
		cmd->ac = (redisAsyncContext*)pool_connect(w->pool, cmd->database, 0);
	} else {
		/* get a connection from the pool */
		cmd->ac = (redisAsyncContext*)pool_get_context(w->pool);
	}

	/* no args (e.g. INFO command) */
	if(!slash) {
		if(!cmd->ac) {
			cmd_free(cmd);
			return CMD_REDIS_UNAVAIL;
		}
		redisAsyncCommandArgv(cmd->ac, f_format, cmd, 1,
				(const char **)cmd->argv, cmd->argv_len);
		return CMD_SENT;
	}
	p = cmd_name + cmd_len + 1;
	while(p < uri + uri_len) {

		const char *arg = p;
		int arg_len;
		char *next = memchr(arg, '/', uri_len - (arg-uri));
		if(!next || next > uri + uri_len) { /* last argument */
			p = uri + uri_len;
			arg_len = p - arg;
		} else { /* found a slash */
			arg_len = next - arg;
			p = next + 1;
		}

		/* record argument */
		cmd->argv[cur_param] = decode_uri(arg, arg_len, &cmd->argv_len[cur_param], 1);
		cur_param++;
	}

	if(body && body_len) { /* PUT request */
		cmd->argv[cur_param] = malloc(body_len);
		memcpy(cmd->argv[cur_param], body, body_len);
		cmd->argv_len[cur_param] = body_len;
	}

	/* send it off! */
	if(cmd->ac) {
		cmd_send(cmd, f_format);
		return CMD_SENT;
	}
	/* failed to find a suitable connection to Redis. */
	cmd_free(cmd);
	client->self_cmd = NULL;
	return CMD_REDIS_UNAVAIL;
}

void
cmd_send(struct cmd *cmd, formatting_fun f_format) {
	redisAsyncCommandArgv(cmd->ac, f_format, cmd, cmd->count,
		(const char **)cmd->argv, cmd->argv_len);
}

/**
 * Select Content-Type and processing function.
 */
int
cmd_select_format(struct http_client *client, struct cmd *cmd,
		const char *uri, size_t uri_len, formatting_fun *f_format) {

	const char *ext;
	int ext_len = -1;
	unsigned int i;
	int found = 0; /* did we match it to a predefined format? */

	/* those are the available reply formats */
	struct reply_format {
		const char *s;
		size_t sz;
		formatting_fun f;
		const char *ct;
	};
	struct reply_format funs[] = {
		{.s = "json", .sz = 4, .f = json_reply, .ct = "application/json"},
		{.s = "raw", .sz = 3, .f = raw_reply, .ct = "binary/octet-stream"},

#ifdef MSGPACK
		{.s = "msg", .sz = 3, .f = msgpack_reply, .ct = "application/x-msgpack"},
#endif

		{.s = "bin", .sz = 3, .f = custom_type_reply, .ct = "binary/octet-stream"},
		{.s = "txt", .sz = 3, .f = custom_type_reply, .ct = "text/plain"},
		{.s = "html", .sz = 4, .f = custom_type_reply, .ct = "text/html"},
		{.s = "xhtml", .sz = 5, .f = custom_type_reply, .ct = "application/xhtml+xml"},
		{.s = "xml", .sz = 3, .f = custom_type_reply, .ct = "text/xml"},

		{.s = "png", .sz = 3, .f = custom_type_reply, .ct = "image/png"},
		{.s = "jpg", .sz = 3, .f = custom_type_reply, .ct = "image/jpeg"},
		{.s = "jpeg", .sz = 4, .f = custom_type_reply, .ct = "image/jpeg"},

		{.s = "js", .sz = 2, .f = json_reply, .ct = "application/javascript"},
		{.s = "css", .sz = 3, .f = custom_type_reply, .ct = "text/css"},
	};

	/* default */
	*f_format = json_reply;

	/* find extension */
	for(ext = uri + uri_len - 1; ext != uri && *ext != '/'; --ext) {
		if(*ext == '.') {
			ext++;
			ext_len = uri + uri_len - ext;
			break;
		}
	}
	if(!ext_len) return uri_len; /* nothing found */

	/* find function for the given extension */
	for(i = 0; i < sizeof(funs)/sizeof(funs[0]); ++i) {
		if(ext_len == (int)funs[i].sz && strncmp(ext, funs[i].s, ext_len) == 0) {

			if(cmd->mime_free) free(cmd->mime);
			cmd->mime = (char*)funs[i].ct;
			cmd->mime_free = 0;

			*f_format = funs[i].f;
			found = 1;
		}
	}

	/* the user can force it with ?type=some/thing */
	if(client->type) {
		*f_format = custom_type_reply;
		/* /!\ we don't copy cmd->mime, this is done soon after in cmd_setup */
	}

	if(found) {
		return uri_len - ext_len - 1;
	} else {
		/* no matching format, use default output with the full argument, extension included. */
		return uri_len;
	}
}

int
cmd_is_subscribe(struct cmd *cmd) {

	if(cmd->pub_sub_client || /* persistent command */
		cmd_is_subscribe_args(cmd)) { /* checked with args */
		return 1;
	}
	return 0;
}

int
cmd_is_subscribe_args(struct cmd *cmd) {

	if(cmd->count >= 2 &&
		((cmd->argv_len[0] == 9 && strncasecmp(cmd->argv[0], "subscribe", 9) == 0) ||
		(cmd->argv_len[0] == 10 && strncasecmp(cmd->argv[0], "psubscribe", 10) == 0))) {
			return 1;
		}
	return 0;
}

int
cmd_is_unsubscribe_args(struct cmd *cmd) {

	if(cmd->count >= 2 &&
		((cmd->argv_len[0] == 11 && strncasecmp(cmd->argv[0], "unsubscribe", 11) == 0) ||
		(cmd->argv_len[0] == 12 && strncasecmp(cmd->argv[0], "punsubscribe", 12) == 0))) {
			return 1;
		}
	return 0;
}