[lttng-tools.git] / src / common / uri.cpp

/*
 * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#define _LGPL_SOURCE
#include <arpa/inet.h>
#include <common/compat/netdb.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>

#include <common/common.h>
#include <common/defaults.h>
#include <common/utils.h>

#include "uri.h"

#define LOOPBACK_ADDR_IPV4 "127.0.0.1"
#define LOOPBACK_ADDR_IPV6 "::1"

enum uri_proto_code {
        P_NET, P_NET6, P_FILE, P_TCP, P_TCP6,
};

struct uri_proto {
        const char *name;
        const char *leading_string;
        enum uri_proto_code code;
        enum lttng_proto_type type;
        enum lttng_dst_type dtype;
};

/* Supported protocols */
static const struct uri_proto proto_uri[] = {
        { .name = "file", .leading_string = "file://", .code = P_FILE, .type = LTTNG_PROTO_TYPE_NONE, .dtype = LTTNG_DST_PATH },
        { .name = "net", .leading_string = "net://", .code = P_NET, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
        { .name = "net4", .leading_string = "net4://", .code = P_NET, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
        { .name = "net6", .leading_string = "net6://", .code = P_NET6, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV6 },
        { .name = "tcp", .leading_string = "tcp://", .code = P_TCP, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
        { .name = "tcp4", .leading_string = "tcp4://", .code = P_TCP, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV4 },
        { .name = "tcp6", .leading_string = "tcp6://", .code = P_TCP6, .type = LTTNG_TCP, .dtype = LTTNG_DST_IPV6 },
        /* Invalid proto marking the end of the array. */
        { 0 }
};

/*
 * Return pointer to the character in s matching one of the characters in
 * accept. If nothing is found, return pointer to the end of string (eos).
 */
static inline const char *strpbrk_or_eos(const char *s, const char *accept)
{
        char *p = (char *) strpbrk(s, accept);
        if (p == NULL) {
                p = (char *) strchr(s, '\0');
        }

        return p;
}

/*
 * Validate if proto is a supported protocol from proto_uri array.
 */
static const struct uri_proto *get_uri_proto(const char *uri_str)
{
        const struct uri_proto *supported = NULL;

        /* Safety net */
        if (uri_str == NULL) {
                goto end;
        }

        for (supported = &proto_uri[0];
                        supported->leading_string != NULL; ++supported) {
                if (strncasecmp(uri_str, supported->leading_string,
                                        strlen(supported->leading_string)) == 0) {
                        goto end;
                }
        }

        /* Proto not found */
        return NULL;

end:
        return supported;
}

/*
 * Set network address from string into dst. Supports both IP string and
 * hostname.
 */
static int set_ip_address(const char *addr, int af, char *dst, size_t size)
{
        int ret;
        unsigned char buf[sizeof(struct in6_addr)];
        struct hostent *record;

        LTTNG_ASSERT(addr);
        LTTNG_ASSERT(dst);

        memset(dst, 0, size);

        /* Network protocol */
        ret = inet_pton(af, addr, buf);
        if (ret < 1) {
                /* We consider the dst to be an hostname or an invalid IP char */
                record = lttng_gethostbyname2(addr, af);
                if (record) {
                        /* Translate IP to string */
                        if (!inet_ntop(af, record->h_addr_list[0], dst, size)) {
                                PERROR("inet_ntop");
                                goto error;
                        }
                } else if (!strcmp(addr, "localhost") &&
                                (af == AF_INET || af == AF_INET6)) {
                        /*
                         * Some systems may not have "localhost" defined in
                         * accordance with IETF RFC 6761. According to this RFC,
                         * applications may recognize "localhost" names as
                         * special and resolve to the appropriate loopback
                         * address.
                         *
                         * We choose to use the system name resolution API first
                         * to honor its network configuration. If this fails, we
                         * resolve to the appropriate loopback address. This is
                         * done to accommodates systems which may want to start
                         * tracing before their network configured.
                         */
                        const char *loopback_addr = af == AF_INET ?
                                        LOOPBACK_ADDR_IPV4 : LOOPBACK_ADDR_IPV6;
                        const size_t loopback_addr_len = af == AF_INET ?
                                        sizeof(LOOPBACK_ADDR_IPV4) :
                                        sizeof(LOOPBACK_ADDR_IPV6);

                        DBG2("Could not resolve localhost address, using fallback");
                        if (loopback_addr_len > size) {
                                ERR("Could not resolve localhost address; destination string is too short");
                                goto error;
                        }
                        strcpy(dst, loopback_addr);
                } else {
                        /* At this point, the IP or the hostname is bad */
                        goto error;
                }
        } else {
                if (size > 0) {
                        strncpy(dst, addr, size);
                        dst[size - 1] = '\0';
                }
        }

        DBG2("IP address resolved to %s", dst);
        return 0;

error:
        ERR("URI parse bad hostname %s for af %d", addr, af);
        return -1;
}

/*
 * Set default URI attribute which is basically the given stream type and the
 * default port if none is set in the URI.
 */
static void set_default_uri_attr(struct lttng_uri *uri,
                enum lttng_stream_type stype)
{
        uri->stype = stype;
        if (uri->dtype != LTTNG_DST_PATH && uri->port == 0) {
                uri->port = (stype == LTTNG_STREAM_CONTROL) ?
                        DEFAULT_NETWORK_CONTROL_PORT : DEFAULT_NETWORK_DATA_PORT;
        }
}

/*
 * Compare two URL destination.
 *
 * Return 0 is equal else is not equal.
 */
static int compare_destination(struct lttng_uri *ctrl, struct lttng_uri *data)
{
        int ret;

        LTTNG_ASSERT(ctrl);
        LTTNG_ASSERT(data);

        switch (ctrl->dtype) {
        case LTTNG_DST_IPV4:
                ret = strncmp(ctrl->dst.ipv4, data->dst.ipv4, sizeof(ctrl->dst.ipv4));
                break;
        case LTTNG_DST_IPV6:
                ret = strncmp(ctrl->dst.ipv6, data->dst.ipv6, sizeof(ctrl->dst.ipv6));
                break;
        default:
                ret = -1;
                break;
        }

        return ret;
}

/*
 * Build a string URL from a lttng_uri object.
 */
int uri_to_str_url(struct lttng_uri *uri, char *dst, size_t size)
{
        int ipver, ret;
        const char *addr;
        char proto[5], port[7];

        LTTNG_ASSERT(uri);
        LTTNG_ASSERT(dst);

        if (uri->dtype == LTTNG_DST_PATH) {
                ipver = 0;
                addr = uri->dst.path;
                (void) snprintf(proto, sizeof(proto), "file");
                (void) snprintf(port, sizeof(port), "%s", "");
        } else {
                ipver = (uri->dtype == LTTNG_DST_IPV4) ? 4 : 6;
                addr = (ipver == 4) ?  uri->dst.ipv4 : uri->dst.ipv6;
                (void) snprintf(proto, sizeof(proto), "tcp%d", ipver);
                (void) snprintf(port, sizeof(port), ":%d", uri->port);
        }

        ret = snprintf(dst, size, "%s://%s%s%s%s/%s", proto,
                        (ipver == 6) ? "[" : "", addr, (ipver == 6) ? "]" : "",
                        port, uri->subdir);
        if (ret < 0) {
                PERROR("snprintf uri to url");
        }

        return ret;
}

/*
 * Compare two URIs.
 *
 * Return 0 if equal else 1.
 */
int uri_compare(struct lttng_uri *uri1, struct lttng_uri *uri2)
{
        return memcmp(uri1, uri2, sizeof(struct lttng_uri));
}

/*
 * Free URI memory.
 */
void uri_free(struct lttng_uri *uri)
{
        free(uri);
}

/*
 * Parses a string URI to a lttng_uri. This function can potentially return
 * more than one URI in uris so the size of the array is returned and uris is
 * allocated and populated. Caller must free(3) the array.
 *
 * This function can not detect the stream type of the URI so the caller has to
 * make sure the correct type (stype) is set on the return URI(s). The default
 * port must also be set by the caller if the returned URI has its port set to
 * zero.
 *
 * NOTE: A good part of the following code was inspired from the "wget" source
 * tree from the src/url.c file and url_parse() function. Also, the
 * strpbrk_or_eos() function found above is also inspired by the same code.
 * This code was originally licensed GPLv2 so we acknolwedge the Free Software
 * Foundation here for the work and to make sure we are compliant with it.
 */
ssize_t uri_parse(const char *str_uri, struct lttng_uri **uris)
{
        int ret, i = 0;
        /* Size of the uris array. Default is 1 */
        ssize_t size = 1;
        char subdir[PATH_MAX];
        unsigned int ctrl_port = 0;
        unsigned int data_port = 0;
        struct lttng_uri *tmp_uris;
        char *addr_f = NULL;
        const struct uri_proto *proto;
        const char *purl, *addr_e, *addr_b, *subdir_b = NULL;
        const char *seps = ":/\0";

        /*
         * The first part is the protocol portion of a maximum of 5 bytes for now.
         * The second part is the hostname or IP address. The 255 bytes size is the
         * limit found in the RFC 1035 for the total length of a domain name
         * (https://www.ietf.org/rfc/rfc1035.txt). Finally, for the net://
         * protocol, two ports CAN be specified.
         */

        DBG3("URI string: %s", str_uri);

        proto = get_uri_proto(str_uri);
        if (proto == NULL) {
                ERR("URI parse unknown protocol %s", str_uri);
                goto error;
        }

        purl = str_uri;

        if (proto->code == P_NET || proto->code == P_NET6) {
                /* Special case for net:// which requires two URI objects */
                size = 2;
        }

        /* Allocate URI array */
        tmp_uris = (lttng_uri *) zmalloc(sizeof(struct lttng_uri) * size);
        if (tmp_uris == NULL) {
                PERROR("zmalloc uri");
                goto error;
        }

        memset(subdir, 0, sizeof(subdir));
        purl += strlen(proto->leading_string);

        /* Copy known value to the first URI. */
        tmp_uris[0].dtype = proto->dtype;
        tmp_uris[0].proto = proto->type;

        if (proto->code == P_FILE) {
                if (*purl != '/') {
                        ERR("Missing destination full path.");
                        goto free_error;
                }

                strncpy(tmp_uris[0].dst.path, purl, sizeof(tmp_uris[0].dst.path));
                tmp_uris[0].dst.path[sizeof(tmp_uris[0].dst.path) - 1] = '\0';
                DBG3("URI file destination: %s", purl);
                goto end;
        }

        /* Assume we are at the beginning of an address or host of some sort. */
        addr_b = purl;

        /*
         * Handle IPv6 address inside square brackets as mention by RFC 2732. IPv6
         * address that does not start AND end with brackets will be rejected even
         * if valid.
         *
         * proto://[<addr>]...
         *         ^
         */
        if (*purl == '[') {
                /* Address begins after '[' */
                addr_b = purl + 1;
                addr_e = strchr(addr_b, ']');
                if (addr_e == NULL || addr_b == addr_e) {
                        ERR("Broken IPv6 address %s", addr_b);
                        goto free_error;
                }

                /* Moving parsed URL pointer after the final bracket ']' */
                purl = addr_e + 1;

                /*
                 * The closing bracket must be followed by a seperator or NULL char.
                 */
                if (strchr(seps, *purl) == NULL) {
                        ERR("Unknown symbol after IPv6 address: %s", purl);
                        goto free_error;
                }
        } else {
                purl = strpbrk_or_eos(purl, seps);
                addr_e = purl;
        }

        /* Check if we at least have a char for the addr or hostname. */
        if (addr_b == addr_e) {
                ERR("No address or hostname detected.");
                goto free_error;
        }

        addr_f = utils_strdupdelim(addr_b, addr_e);
        if (addr_f == NULL) {
                goto free_error;
        }

        /*
         * Detect PORT after address. The net/net6 protocol allows up to two port
         * so we can define the control and data port.
         */
        while (*purl == ':') {
                const char *port_b, *port_e;
                char *port_f;

                /* Update pass counter */
                i++;

                /*
                 * Maximum of two ports is possible if P_NET/NET6. Bigger than that,
                 * two much stuff.
                 */
                if ((i == 2 && (proto->code != P_NET && proto->code != P_NET6))
                                || i > 2) {
                        break;
                }

                /*
                 * Move parsed URL to port value.
                 * proto://addr_host:PORT1:PORT2/foo/bar
                 *                   ^
                 */
                ++purl;
                port_b = purl;
                purl = strpbrk_or_eos(purl, seps);
                port_e = purl;

                if (port_b != port_e) {
                        int port;

                        port_f = utils_strdupdelim(port_b, port_e);
                        if (port_f == NULL) {
                                goto free_error;
                        }

                        port = atoi(port_f);
                        if (port > 0xffff || port <= 0x0) {
                                ERR("Invalid port number %d", port);
                                free(port_f);
                                goto free_error;
                        }
                        free(port_f);

                        if (i == 1) {
                                ctrl_port = port;
                        } else {
                                data_port = port;
                        }
                }
        };

        /* Check for a valid subdir or trailing garbage */
        if (*purl == '/') {
                /*
                 * Move to subdir value.
                 * proto://addr_host:PORT1:PORT2/foo/bar
                 *                               ^
                 */
                ++purl;
                subdir_b = purl;
        } else if (*purl != '\0') {
                ERR("Trailing characters not recognized: %s", purl);
                goto free_error;
        }

        /* We have enough valid information to create URI(s) object */

        /* Copy generic information */
        tmp_uris[0].port = ctrl_port;

        /* Copy subdirectory if one. */
        if (subdir_b) {
                strncpy(tmp_uris[0].subdir, subdir_b, sizeof(tmp_uris[0].subdir));
                tmp_uris[0].subdir[sizeof(tmp_uris[0].subdir) - 1] = '\0';
        }

        switch (proto->code) {
        case P_NET:
                ret = set_ip_address(addr_f, AF_INET, tmp_uris[0].dst.ipv4,
                                sizeof(tmp_uris[0].dst.ipv4));
                if (ret < 0) {
                        goto free_error;
                }

                memcpy(tmp_uris[1].dst.ipv4, tmp_uris[0].dst.ipv4, sizeof(tmp_uris[1].dst.ipv4));

                tmp_uris[1].dtype = proto->dtype;
                tmp_uris[1].proto = proto->type;
                tmp_uris[1].port = data_port;
                break;
        case P_NET6:
                ret = set_ip_address(addr_f, AF_INET6, tmp_uris[0].dst.ipv6,
                                sizeof(tmp_uris[0].dst.ipv6));
                if (ret < 0) {
                        goto free_error;
                }

                memcpy(tmp_uris[1].dst.ipv6, tmp_uris[0].dst.ipv6, sizeof(tmp_uris[1].dst.ipv6));

                tmp_uris[1].dtype = proto->dtype;
                tmp_uris[1].proto = proto->type;
                tmp_uris[1].port = data_port;
                break;
        case P_TCP:
                ret = set_ip_address(addr_f, AF_INET, tmp_uris[0].dst.ipv4,
                                sizeof(tmp_uris[0].dst.ipv4));
                if (ret < 0) {
                        goto free_error;
                }
                break;
        case P_TCP6:
                ret = set_ip_address(addr_f, AF_INET6, tmp_uris[0].dst.ipv6,
                                sizeof(tmp_uris[0].dst.ipv6));
                if (ret < 0) {
                        goto free_error;
                }
                break;
        default:
                goto free_error;
        }

end:
        DBG3("URI dtype: %d, proto: %d, host: %s, subdir: %s, ctrl: %d, data: %d",
                        proto->dtype, proto->type, (addr_f == NULL) ? "" : addr_f,
                        (subdir_b == NULL) ? "" : subdir_b, ctrl_port, data_port);

        free(addr_f);

        *uris = tmp_uris;
        LTTNG_ASSERT(size == 1 || size == 2);
        return size;

free_error:
        free(addr_f);
        free(tmp_uris);
error:
        return -1;
}

/*
 * Parse a string URL and creates URI(s) returning the size of the populated
 * array.
 */
ssize_t uri_parse_str_urls(const char *ctrl_url, const char *data_url,
                struct lttng_uri **uris)
{
        unsigned int equal = 1, idx = 0;
        /* Add the "file://" size to the URL maximum size */
        char url[PATH_MAX + 7];
        ssize_t ctrl_uri_count = 0, data_uri_count = 0, uri_count;
        struct lttng_uri *ctrl_uris = NULL, *data_uris = NULL;
        struct lttng_uri *tmp_uris = NULL;

        /* No URL(s) is allowed. This means that the consumer will be disabled. */
        if (ctrl_url == NULL && data_url == NULL) {
                return 0;
        }

        /* Check if URLs are equal and if so, only use the control URL */
        if ((ctrl_url && *ctrl_url != '\0') && (data_url && *data_url != '\0')) {
                equal = !strcmp(ctrl_url, data_url);
        }

        /*
         * Since we allow the str_url to be a full local filesystem path, we are
         * going to create a valid file:// URL if it's the case.
         *
         * Check if first character is a '/' or else reject the URL.
         */
        if (ctrl_url && ctrl_url[0] == '/') {
                int ret;

                ret = snprintf(url, sizeof(url), "file://%s", ctrl_url);
                if (ret < 0) {
                        PERROR("snprintf file url");
                        goto parse_error;
                } else if (ret >= sizeof(url)) {
                        PERROR("snprintf file url is too long");
                        goto parse_error;

                }
                ctrl_url = url;
        }

        /* Parse the control URL if there is one */
        if (ctrl_url && *ctrl_url != '\0') {
                ctrl_uri_count = uri_parse(ctrl_url, &ctrl_uris);
                if (ctrl_uri_count < 1) {
                        ERR("Unable to parse the URL %s", ctrl_url);
                        goto parse_error;
                }

                /* 1 and 2 are the only expected values on success. */
                LTTNG_ASSERT(ctrl_uri_count == 1 || ctrl_uri_count == 2);

                /* At this point, we know there is at least one URI in the array */
                set_default_uri_attr(&ctrl_uris[0], LTTNG_STREAM_CONTROL);

                if (ctrl_uris[0].dtype == LTTNG_DST_PATH &&
                                (data_url && *data_url != '\0')) {
                        ERR("Cannot have a data URL when destination is file://");
                        goto error;
                }

                /* URL are not equal but the control URL uses a net:// protocol */
                if (ctrl_uri_count == 2) {
                        if (!equal) {
                                ERR("Control URL uses the net:// protocol and the data URL is "
                                                "different. Not allowed.");
                                goto error;
                        } else {
                                set_default_uri_attr(&ctrl_uris[1], LTTNG_STREAM_DATA);
                                /*
                                 * The data_url and ctrl_url are equal and the ctrl_url
                                 * contains a net:// protocol so we just skip the data part.
                                 */
                                data_url = NULL;
                        }
                }
        }

        if (data_url && *data_url != '\0') {
                int ret;

                /* We have to parse the data URL in this case */
                data_uri_count = uri_parse(data_url, &data_uris);
                if (data_uri_count < 1) {
                        ERR("Unable to parse the URL %s", data_url);
                        goto error;
                } else if (data_uri_count == 2) {
                        ERR("Data URL can not be set with the net[4|6]:// protocol");
                        goto error;
                } else {
                        /* 1 and 2 are the only expected values on success. */
                        LTTNG_ASSERT(data_uri_count == 1);
                }

                set_default_uri_attr(&data_uris[0], LTTNG_STREAM_DATA);

                if (ctrl_uris) {
                        ret = compare_destination(&ctrl_uris[0], &data_uris[0]);
                        if (ret != 0) {
                                ERR("Control and data destination mismatch");
                                goto error;
                        }
                }
        }

        /* Compute total size. */
        uri_count = ctrl_uri_count + data_uri_count;
        if (uri_count <= 0) {
                goto error;
        }

        tmp_uris = (lttng_uri *) zmalloc(sizeof(struct lttng_uri) * uri_count);
        if (tmp_uris == NULL) {
                PERROR("zmalloc uris");
                goto error;
        }

        if (ctrl_uris) {
                /* It's possible the control URIs array contains more than one URI */
                memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * ctrl_uri_count);
                ++idx;
                free(ctrl_uris);
        }

        if (data_uris) {
                memcpy(&tmp_uris[idx], data_uris, sizeof(struct lttng_uri));
                free(data_uris);
        }

        *uris = tmp_uris;

        return uri_count;

error:
        free(ctrl_uris);
        free(data_uris);
        free(tmp_uris);
parse_error:
        return -1;
}