/src/pacemaker/lib/common/ipc_common.c

Source
/*
 * Copyright 2004-2025 the Pacemaker project contributors
 *
 * The version control history for this file may have further details.
 *
 * This source code is licensed under the GNU Lesser General Public License
 * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
 */

#include <crm_internal.h>

#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>         // uint64_t
#include <sys/types.h>

#include <crm/common/xml.h>
#include "crmcommon_private.h"

/* The IPC buffer is always 128k.  If we are asked to send a message larger
 * than that size, it will be split into multiple messages that must be
 * reassembled on the other end.
 */
#define BUFFER_SIZE     (128*1024) // 128k

/*!
 * \brief Return pacemaker's IPC buffer size
 *
 * \return IPC buffer size in bytes
 */
unsigned int
crm_ipc_default_buffer_size(void)
{
    return BUFFER_SIZE;
}

/*!
 * \internal
 * \brief Check whether an IPC header is valid
 *
 * \param[in] header  IPC header to check
 *
 * \return true if IPC header has a supported version, false otherwise
 */
bool
pcmk__valid_ipc_header(const pcmk__ipc_header_t *header)
{
    if (header == NULL) {
        pcmk__err("IPC message without header");
        return false;

    } else if (header->version > PCMK__IPC_VERSION) {
        pcmk__err("Filtering incompatible v%d IPC message (only versions <= %d "
                  "supported)",
                  header->version, PCMK__IPC_VERSION);
        return false;
    }
    return true;
}

const char *
pcmk__client_type_str(uint64_t client_type)
{
    switch (client_type) {
        case pcmk__client_ipc:
            return "IPC";
        case pcmk__client_tcp:
            return "TCP";
        case pcmk__client_tls:
            return "TLS";
        default:
            return "unknown";
    }
}

/*!
 * \internal
 * \brief Add more data to a received partial IPC message
 *
 * This function can be called repeatedly to build up a complete IPC message
 * from smaller parts.  It does this by inspecting flags on the message.
 * Most of the time, IPC messages will be small enough where this function
 * won't get called more than once, but more complex clusters can end up with
 * very large IPC messages that don't fit in a single buffer.
 *
 * Important return values:
 *
 * - EBADMSG - Something was wrong with the data.
 * - pcmk_rc_ipc_more - \p data was a chunk of a partial message and there is
 *                      more to come.  The caller should not process the message
 *                      yet and should continue reading from the IPC connection.
 * - pcmk_rc_ok - We have the complete message.  The caller should process
 *                it and free the buffer to prepare for the next message.
 *
 * \param[in,out] buffer The buffer to add this data to
 * \param[in]     data   The received IPC message or message portion.
 *
 * \return Standard Pacemaker return code
 */
int
pcmk__ipc_msg_append(GByteArray **buffer, guint8 *data)
{
    pcmk__ipc_header_t *full_header = NULL;
    pcmk__ipc_header_t *header = (pcmk__ipc_header_t *) (void *) data;
    const guint8 *payload = (guint8 *) data + sizeof(pcmk__ipc_header_t);
    int rc = pcmk_rc_ok;

    if (!pcmk__valid_ipc_header(header)) {
        return EBADMSG;
    }

    if (pcmk__is_set(header->flags, crm_ipc_multipart_end)) {
        full_header = (pcmk__ipc_header_t *) (void *) (*buffer)->data;

        /* This is the end of a multipart IPC message.  Add the payload of the
         * received data (so, don't include the header) to the partial buffer.
         * Remember that this needs to include the null terminating character.
         */
        CRM_CHECK(buffer != NULL && *buffer != NULL && header->part_id != 0,
                  return EINVAL);
        CRM_CHECK(full_header->qb.id == header->qb.id, return EBADMSG);
        g_byte_array_append(*buffer, payload, header->size);

        pcmk__trace("Received IPC message %" PRId32 " (final part %" PRIu16 ") "
                    "of %" PRId32 " bytes",
                    header->qb.id, header->part_id, header->qb.size);

    } else if (pcmk__is_set(header->flags, crm_ipc_multipart)) {
        if (header->part_id == 0) {
            /* This is the first part of a multipart IPC message.  Initialize
             * the buffer with the entire message, including its header.  Do
             * not include the null terminating character.
             */
            CRM_CHECK(buffer != NULL && *buffer == NULL, return EINVAL);
            *buffer = g_byte_array_new();

            /* Clear any multipart flags from the header of the incoming part
             * so they'll be clear in the fully reassembled message.  This
             * message is passed to pcmk__client_data2xml, which will extract
             * the header flags and return them.  Those flags can then be used
             * when constructing a reply, including ACKs.  We don't want these
             * specific incoming flags to influence the reply.
             */
            pcmk__clear_ipc_flags(header->flags, "server", crm_ipc_multipart);

            g_byte_array_append(*buffer, data,
                                sizeof(pcmk__ipc_header_t) + header->size - 1);

        } else {
            full_header = (pcmk__ipc_header_t *) (void *) (*buffer)->data;

            /* This is some intermediate part of a multipart message.  Add
             * the payload of the received data (so, don't include the header)
             * to the partial buffer and return.  Do not include the null
             * terminating character.
             */
            CRM_CHECK(buffer != NULL && *buffer != NULL, return EINVAL);
            CRM_CHECK(full_header->qb.id == header->qb.id, return EBADMSG);
            g_byte_array_append(*buffer, payload, header->size - 1);
        }

        pcmk__trace("Received IPC message %" PRId32 " (part %" PRIu16 ") "
                    "of %" PRId32 " bytes",
                    header->qb.id, header->part_id, header->qb.size);

        rc = pcmk_rc_ipc_more;

    } else {
        /* This is a standalone IPC message.  For simplicity in the caller,
         * copy the entire message over into a byte array so it can be handled
         * the same as a multipart message.
         */
        CRM_CHECK(buffer != NULL && *buffer == NULL, return EINVAL);
        *buffer = g_byte_array_new();
        g_byte_array_append(*buffer, data,
                            sizeof(pcmk__ipc_header_t) + header->size);

        pcmk__trace("Received IPC message %" PRId32 " of %" PRId32 " bytes",
                    header->qb.id, header->qb.size);
    }

    pcmk__trace("Text = %s", payload);
    pcmk__trace("Buffer = %s", (*buffer)->data + sizeof(pcmk__ipc_header_t));

    /* The buffer's header should have a size that matches the full size of
     * the received message, not just the last chunk of it.
     */
    full_header = (pcmk__ipc_header_t *) (void *) (*buffer)->data;
    full_header->size = (*buffer)->len - sizeof(pcmk__ipc_header_t);

    return rc;
}

Line	Count	Source
1		/*
2		* Copyright 2004-2025 the Pacemaker project contributors
3		*
4		* The version control history for this file may have further details.
5		*
6		* This source code is licensed under the GNU Lesser General Public License
7		* version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
8		*/
9
10		#include <crm_internal.h>
11
12		#include <stdbool.h>
13		#include <stdio.h>
14		#include <stdint.h> // uint64_t
15		#include <sys/types.h>
16
17		#include <crm/common/xml.h>
18		#include "crmcommon_private.h"
19
20		/* The IPC buffer is always 128k. If we are asked to send a message larger
21		* than that size, it will be split into multiple messages that must be
22		* reassembled on the other end.
23		*/
24	0	#define BUFFER_SIZE (128*1024) // 128k
25
26		/*!
27		* \brief Return pacemaker's IPC buffer size
28		*
29		* \return IPC buffer size in bytes
30		*/
31		unsigned int
32		crm_ipc_default_buffer_size(void)
33	0	{
34	0	return BUFFER_SIZE;
35	0	}
36
37		/*!
38		* \internal
39		* \brief Check whether an IPC header is valid
40		*
41		* \param[in] header IPC header to check
42		*
43		* \return true if IPC header has a supported version, false otherwise
44		*/
45		bool
46		pcmk__valid_ipc_header(const pcmk__ipc_header_t *header)
47	0	{
48	0	if (header == NULL) {
49	0	pcmk__err("IPC message without header");
50	0	return false;
51
52	0	} else if (header->version > PCMK__IPC_VERSION) {
53	0	pcmk__err("Filtering incompatible v%d IPC message (only versions <= %d "
54	0	"supported)",
55	0	header->version, PCMK__IPC_VERSION);
56	0	return false;
57	0	}
58	0	return true;
59	0	}
60
61		const char *
62		pcmk__client_type_str(uint64_t client_type)
63	0	{
64	0	switch (client_type) {
65	0	case pcmk__client_ipc:
66	0	return "IPC";
67	0	case pcmk__client_tcp:
68	0	return "TCP";
69	0	case pcmk__client_tls:
70	0	return "TLS";
71	0	default:
72	0	return "unknown";
73	0	}
74	0	}
75
76		/*!
77		* \internal
78		* \brief Add more data to a received partial IPC message
79		*
80		* This function can be called repeatedly to build up a complete IPC message
81		* from smaller parts. It does this by inspecting flags on the message.
82		* Most of the time, IPC messages will be small enough where this function
83		* won't get called more than once, but more complex clusters can end up with
84		* very large IPC messages that don't fit in a single buffer.
85		*
86		* Important return values:
87		*
88		* - EBADMSG - Something was wrong with the data.
89		* - pcmk_rc_ipc_more - \p data was a chunk of a partial message and there is
90		* more to come. The caller should not process the message
91		* yet and should continue reading from the IPC connection.
92		* - pcmk_rc_ok - We have the complete message. The caller should process
93		* it and free the buffer to prepare for the next message.
94		*
95		* \param[in,out] buffer The buffer to add this data to
96		* \param[in] data The received IPC message or message portion.
97		*
98		* \return Standard Pacemaker return code
99		*/
100		int
101		pcmk__ipc_msg_append(GByteArray *buffer, guint8 data)
102	0	{
103	0	pcmk__ipc_header_t *full_header = NULL;
104	0	pcmk__ipc_header_t header = (pcmk__ipc_header_t ) (void *) data;
105	0	const guint8 payload = (guint8 ) data + sizeof(pcmk__ipc_header_t);
106	0	int rc = pcmk_rc_ok;
107
108	0	if (!pcmk__valid_ipc_header(header)) {
109	0	return EBADMSG;
110	0	}
111
112	0	if (pcmk__is_set(header->flags, crm_ipc_multipart_end)) {
113	0	full_header = (pcmk__ipc_header_t ) (void ) (*buffer)->data;
114
115		/* This is the end of a multipart IPC message. Add the payload of the
116		* received data (so, don't include the header) to the partial buffer.
117		* Remember that this needs to include the null terminating character.
118		*/
119	0	CRM_CHECK(buffer != NULL && *buffer != NULL && header->part_id != 0,
120	0	return EINVAL);
121	0	CRM_CHECK(full_header->qb.id == header->qb.id, return EBADMSG);
122	0	g_byte_array_append(*buffer, payload, header->size);
123
124	0	pcmk__trace("Received IPC message %" PRId32 " (final part %" PRIu16 ") "
125	0	"of %" PRId32 " bytes",
126	0	header->qb.id, header->part_id, header->qb.size);
127
128	0	} else if (pcmk__is_set(header->flags, crm_ipc_multipart)) {
129	0	if (header->part_id == 0) {
130		/* This is the first part of a multipart IPC message. Initialize
131		* the buffer with the entire message, including its header. Do
132		* not include the null terminating character.
133		*/
134	0	CRM_CHECK(buffer != NULL && *buffer == NULL, return EINVAL);
135	0	*buffer = g_byte_array_new();
136
137		/* Clear any multipart flags from the header of the incoming part
138		* so they'll be clear in the fully reassembled message. This
139		* message is passed to pcmk__client_data2xml, which will extract
140		* the header flags and return them. Those flags can then be used
141		* when constructing a reply, including ACKs. We don't want these
142		* specific incoming flags to influence the reply.
143		*/
144	0	pcmk__clear_ipc_flags(header->flags, "server", crm_ipc_multipart);
145
146	0	g_byte_array_append(*buffer, data,
147	0	sizeof(pcmk__ipc_header_t) + header->size - 1);
148
149	0	} else {
150	0	full_header = (pcmk__ipc_header_t ) (void ) (*buffer)->data;
151
152		/* This is some intermediate part of a multipart message. Add
153		* the payload of the received data (so, don't include the header)
154		* to the partial buffer and return. Do not include the null
155		* terminating character.
156		*/
157	0	CRM_CHECK(buffer != NULL && *buffer != NULL, return EINVAL);
158	0	CRM_CHECK(full_header->qb.id == header->qb.id, return EBADMSG);
159	0	g_byte_array_append(*buffer, payload, header->size - 1);
160	0	}
161
162	0	pcmk__trace("Received IPC message %" PRId32 " (part %" PRIu16 ") "
163	0	"of %" PRId32 " bytes",
164	0	header->qb.id, header->part_id, header->qb.size);
165
166	0	rc = pcmk_rc_ipc_more;
167
168	0	} else {
169		/* This is a standalone IPC message. For simplicity in the caller,
170		* copy the entire message over into a byte array so it can be handled
171		* the same as a multipart message.
172		*/
173	0	CRM_CHECK(buffer != NULL && *buffer == NULL, return EINVAL);
174	0	*buffer = g_byte_array_new();
175	0	g_byte_array_append(*buffer, data,
176	0	sizeof(pcmk__ipc_header_t) + header->size);
177
178	0	pcmk__trace("Received IPC message %" PRId32 " of %" PRId32 " bytes",
179	0	header->qb.id, header->qb.size);
180	0	}
181
182	0	pcmk__trace("Text = %s", payload);
183	0	pcmk__trace("Buffer = %s", (*buffer)->data + sizeof(pcmk__ipc_header_t));
184
185		/* The buffer's header should have a size that matches the full size of
186		* the received message, not just the last chunk of it.
187		*/
188	0	full_header = (pcmk__ipc_header_t ) (void ) (*buffer)->data;
189	0	full_header->size = (*buffer)->len - sizeof(pcmk__ipc_header_t);
190
191	0	return rc;
192	0	}

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Created: 2026-01-03 06:24