diff options
Diffstat (limited to 'shmem/unix/shm.c')
| -rw-r--r-- | shmem/unix/shm.c | 731 |
1 files changed, 731 insertions, 0 deletions
diff --git a/shmem/unix/shm.c b/shmem/unix/shm.c new file mode 100644 index 0000000..f99afec --- /dev/null +++ b/shmem/unix/shm.c @@ -0,0 +1,731 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "apr_arch_shm.h" +#include "apr_arch_file_io.h" + +#include "apr_general.h" +#include "apr_errno.h" +#include "apr_user.h" +#include "apr_strings.h" +#include "apr_hash.h" + +#if APR_USE_SHMEM_MMAP_SHM +/* + * For portable use, a shared memory object should be identified by a name of + * the form /somename; that is, a null-terminated string of up to NAME_MAX + * (i.e., 255) characters consisting of an initial slash, followed by one or + * more characters, none of which are slashes. + */ +#ifndef NAME_MAX +#define NAME_MAX 255 +#endif + +/* See proc_mutex.c and sem_open for the reason for all this! */ +static unsigned int rshash (const char *p) { + /* hash function from Robert Sedgwicks 'Algorithms in C' book */ + unsigned int b = 378551; + unsigned int a = 63689; + unsigned int retval = 0; + + for( ; *p; p++) { + retval = retval * a + (*p); + a *= b; + } + + return retval; +} + +static const char *make_shm_open_safe_name(const char *filename, + apr_pool_t *pool) +{ + apr_ssize_t flen; + unsigned int h1, h2; + + if (filename == NULL) { + return NULL; + } + + flen = strlen(filename); + h1 = (apr_hashfunc_default(filename, &flen) & 0xffffffff); + h2 = (rshash(filename) & 0xffffffff); + return apr_psprintf(pool, "/ShM.%xH%x", h1, h2); + +} +#endif + +#if APR_USE_SHMEM_SHMGET +static key_t our_ftok(const char *filename) +{ + /* to help avoid collisions while still using + * an easily recreated proj_id */ + apr_ssize_t slen = strlen(filename); + return ftok(filename, + (int)apr_hashfunc_default(filename, &slen)); +} +#endif + +static apr_status_t shm_cleanup_owner(void *m_) +{ + apr_shm_t *m = (apr_shm_t *)m_; + + /* anonymous shared memory */ + if (m->filename == NULL) { +#if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_MMAP_ANON + if (munmap(m->base, m->realsize) == -1) { + return errno; + } + return APR_SUCCESS; +#elif APR_USE_SHMEM_SHMGET_ANON + if (shmdt(m->base) == -1) { + return errno; + } + /* This segment will automatically remove itself after all + * references have detached. */ + return APR_SUCCESS; +#endif + } + + /* name-based shared memory */ + else { +#if APR_USE_SHMEM_MMAP_TMP + if (munmap(m->base, m->realsize) == -1) { + return errno; + } + if (access(m->filename, F_OK)) { + return APR_SUCCESS; + } + else { + return apr_file_remove(m->filename, m->pool); + } +#elif APR_USE_SHMEM_MMAP_SHM + if (munmap(m->base, m->realsize) == -1) { + return errno; + } + if (shm_unlink(make_shm_open_safe_name(m->filename, m->pool)) == -1 && errno != ENOENT) { + return errno; + } + return APR_SUCCESS; +#elif APR_USE_SHMEM_SHMGET + /* Indicate that the segment is to be destroyed as soon + * as all processes have detached. This also disallows any + * new attachments to the segment. */ + if (shmctl(m->shmid, IPC_RMID, NULL) == -1 && errno != EINVAL) { + return errno; + } + if (shmdt(m->base) == -1) { + return errno; + } + if (access(m->filename, F_OK)) { + return APR_SUCCESS; + } + else { + return apr_file_remove(m->filename, m->pool); + } +#else + return APR_ENOTIMPL; +#endif + } +} + +APR_DECLARE(apr_status_t) apr_shm_create(apr_shm_t **m, + apr_size_t reqsize, + const char *filename, + apr_pool_t *pool) +{ + apr_shm_t *new_m; + apr_status_t status; +#if APR_USE_SHMEM_SHMGET || APR_USE_SHMEM_SHMGET_ANON + struct shmid_ds shmbuf; + apr_uid_t uid; + apr_gid_t gid; +#endif +#if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM || \ + APR_USE_SHMEM_MMAP_ZERO + int tmpfd; +#endif +#if APR_USE_SHMEM_SHMGET + apr_size_t nbytes; +#endif +#if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_SHMGET || \ + APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM + apr_file_t *file; /* file where metadata is stored */ +#endif + + /* Check if they want anonymous or name-based shared memory */ + if (filename == NULL) { +#if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_MMAP_ANON + new_m = apr_palloc(pool, sizeof(apr_shm_t)); + new_m->pool = pool; + new_m->reqsize = reqsize; + new_m->realsize = reqsize + + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); /* room for metadata */ + new_m->filename = NULL; + +#if APR_USE_SHMEM_MMAP_ZERO + status = apr_file_open(&file, "/dev/zero", APR_READ | APR_WRITE, + APR_OS_DEFAULT, pool); + if (status != APR_SUCCESS) { + return status; + } + status = apr_os_file_get(&tmpfd, file); + if (status != APR_SUCCESS) { + return status; + } + + new_m->base = mmap(NULL, new_m->realsize, PROT_READ|PROT_WRITE, + MAP_SHARED, tmpfd, 0); + if (new_m->base == (void *)MAP_FAILED) { + return errno; + } + + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } + + /* store the real size in the metadata */ + *(apr_size_t*)(new_m->base) = new_m->realsize; + /* metadata isn't usable */ + new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#elif APR_USE_SHMEM_MMAP_ANON + new_m->base = mmap(NULL, new_m->realsize, PROT_READ|PROT_WRITE, + MAP_ANON|MAP_SHARED, -1, 0); + if (new_m->base == (void *)MAP_FAILED) { + return errno; + } + + /* store the real size in the metadata */ + *(apr_size_t*)(new_m->base) = new_m->realsize; + /* metadata isn't usable */ + new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#endif /* APR_USE_SHMEM_MMAP_ZERO */ +#elif APR_USE_SHMEM_SHMGET_ANON + new_m = apr_palloc(pool, sizeof(apr_shm_t)); + new_m->pool = pool; + new_m->reqsize = reqsize; + new_m->realsize = reqsize; + new_m->filename = NULL; + new_m->shmkey = IPC_PRIVATE; + if ((new_m->shmid = shmget(new_m->shmkey, new_m->realsize, + SHM_R | SHM_W | IPC_CREAT)) < 0) { + return errno; + } + + if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) { + return errno; + } + new_m->usable = new_m->base; + + if (shmctl(new_m->shmid, IPC_STAT, &shmbuf) == -1) { + return errno; + } + apr_uid_current(&uid, &gid, pool); + shmbuf.shm_perm.uid = uid; + shmbuf.shm_perm.gid = gid; + if (shmctl(new_m->shmid, IPC_SET, &shmbuf) == -1) { + return errno; + } + + /* Remove the segment once use count hits zero. + * We will not attach to this segment again, since it is + * anonymous memory, so it is ok to mark it for deletion. + */ + if (shmctl(new_m->shmid, IPC_RMID, NULL) == -1) { + return errno; + } + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; +#else + /* It is an error if they want anonymous memory but we don't have it. */ + return APR_ENOTIMPL; /* requested anonymous but we don't have it */ +#endif + } + + /* Name-based shared memory */ + else { + new_m = apr_palloc(pool, sizeof(apr_shm_t)); + new_m->pool = pool; + new_m->reqsize = reqsize; + new_m->filename = apr_pstrdup(pool, filename); +#if APR_USE_SHMEM_MMAP_SHM + const char *shm_name = make_shm_open_safe_name(filename, pool); +#endif +#if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM + new_m->realsize = reqsize + + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); /* room for metadata */ + /* FIXME: Ignore error for now. * + * status = apr_file_remove(file, pool);*/ + status = APR_SUCCESS; + +#if APR_USE_SHMEM_MMAP_TMP + /* FIXME: Is APR_OS_DEFAULT sufficient? */ + status = apr_file_open(&file, filename, + APR_READ | APR_WRITE | APR_CREATE | APR_EXCL, + APR_OS_DEFAULT, pool); + if (status != APR_SUCCESS) { + return status; + } + + status = apr_os_file_get(&tmpfd, file); + if (status != APR_SUCCESS) { + apr_file_close(file); /* ignore errors, we're failing */ + apr_file_remove(new_m->filename, new_m->pool); + return status; + } + + status = apr_file_trunc(file, new_m->realsize); + if (status != APR_SUCCESS && status != APR_ESPIPE) { + apr_file_close(file); /* ignore errors, we're failing */ + apr_file_remove(new_m->filename, new_m->pool); + return status; + } + + new_m->base = mmap(NULL, new_m->realsize, PROT_READ | PROT_WRITE, + MAP_SHARED, tmpfd, 0); + /* FIXME: check for errors */ + + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } +#endif /* APR_USE_SHMEM_MMAP_TMP */ +#if APR_USE_SHMEM_MMAP_SHM + /* FIXME: SysV uses 0600... should we? */ + tmpfd = shm_open(shm_name, O_RDWR | O_CREAT | O_EXCL, 0644); + if (tmpfd == -1) { + return errno; + } + + status = apr_os_file_put(&file, &tmpfd, + APR_READ | APR_WRITE | APR_CREATE | APR_EXCL, + pool); + if (status != APR_SUCCESS) { + return status; + } + + status = apr_file_trunc(file, new_m->realsize); + if (status != APR_SUCCESS && status != APR_ESPIPE) { + shm_unlink(shm_name); /* we're failing, remove the object */ + return status; + } + new_m->base = mmap(NULL, new_m->realsize, PROT_READ | PROT_WRITE, + MAP_SHARED, tmpfd, 0); + + /* FIXME: check for errors */ + + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } +#endif /* APR_USE_SHMEM_MMAP_SHM */ + + /* store the real size in the metadata */ + *(apr_size_t*)(new_m->base) = new_m->realsize; + /* metadata isn't usable */ + new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#elif APR_USE_SHMEM_SHMGET + new_m->realsize = reqsize; + + /* FIXME: APR_OS_DEFAULT is too permissive, switch to 600 I think. */ + status = apr_file_open(&file, filename, + APR_FOPEN_WRITE | APR_FOPEN_CREATE | APR_FOPEN_EXCL, + APR_OS_DEFAULT, pool); + if (status != APR_SUCCESS) { + return status; + } + + /* ftok() (on solaris at least) requires that the file actually + * exist before calling ftok(). */ + new_m->shmkey = our_ftok(filename); + if (new_m->shmkey == (key_t)-1) { + apr_file_close(file); + return errno; + } + + if ((new_m->shmid = shmget(new_m->shmkey, new_m->realsize, + SHM_R | SHM_W | IPC_CREAT | IPC_EXCL)) < 0) { + apr_file_close(file); + return errno; + } + + if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) { + apr_file_close(file); + return errno; + } + new_m->usable = new_m->base; + + if (shmctl(new_m->shmid, IPC_STAT, &shmbuf) == -1) { + apr_file_close(file); + return errno; + } + apr_uid_current(&uid, &gid, pool); + shmbuf.shm_perm.uid = uid; + shmbuf.shm_perm.gid = gid; + if (shmctl(new_m->shmid, IPC_SET, &shmbuf) == -1) { + apr_file_close(file); + return errno; + } + + nbytes = sizeof(reqsize); + status = apr_file_write(file, (const void *)&reqsize, + &nbytes); + if (status != APR_SUCCESS) { + apr_file_close(file); + return status; + } + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#else + return APR_ENOTIMPL; +#endif + } +} + +APR_DECLARE(apr_status_t) apr_shm_create_ex(apr_shm_t **m, + apr_size_t reqsize, + const char *filename, + apr_pool_t *p, + apr_int32_t flags) +{ + return apr_shm_create(m, reqsize, filename, p); +} + +APR_DECLARE(apr_status_t) apr_shm_remove(const char *filename, + apr_pool_t *pool) +{ +#if APR_USE_SHMEM_SHMGET + apr_status_t status; + apr_file_t *file; + key_t shmkey; + int shmid; +#endif + +#if APR_USE_SHMEM_MMAP_TMP + return apr_file_remove(filename, pool); +#elif APR_USE_SHMEM_MMAP_SHM + const char *shm_name = make_shm_open_safe_name(filename, pool); + if (shm_unlink(shm_name) == -1) { + return errno; + } + return APR_SUCCESS; +#elif APR_USE_SHMEM_SHMGET + /* Presume that the file already exists; just open for writing */ + status = apr_file_open(&file, filename, APR_FOPEN_WRITE, + APR_OS_DEFAULT, pool); + if (status) { + return status; + } + + /* ftok() (on solaris at least) requires that the file actually + * exist before calling ftok(). */ + shmkey = our_ftok(filename); + if (shmkey == (key_t)-1) { + goto shm_remove_failed; + } + + apr_file_close(file); + + if ((shmid = shmget(shmkey, 0, SHM_R | SHM_W)) < 0) { + goto shm_remove_failed; + } + + /* Indicate that the segment is to be destroyed as soon + * as all processes have detached. This also disallows any + * new attachments to the segment. */ + if (shmctl(shmid, IPC_RMID, NULL) == -1) { + goto shm_remove_failed; + } + return apr_file_remove(filename, pool); + +shm_remove_failed: + status = errno; + /* ensure the file has been removed anyway. */ + apr_file_remove(filename, pool); + return status; +#else + + /* No support for anonymous shm */ + return APR_ENOTIMPL; +#endif +} + +APR_DECLARE(apr_status_t) apr_shm_delete(apr_shm_t *m) +{ + if (m->filename) { + return apr_shm_remove(m->filename, m->pool); + } + else { + return APR_ENOTIMPL; + } +} + +APR_DECLARE(apr_status_t) apr_shm_destroy(apr_shm_t *m) +{ + return apr_pool_cleanup_run(m->pool, m, shm_cleanup_owner); +} + +static apr_status_t shm_cleanup_attach(void *m_) +{ + apr_shm_t *m = (apr_shm_t *)m_; + + if (m->filename == NULL) { + /* It doesn't make sense to detach from an anonymous memory segment. */ + return APR_EINVAL; + } + else { +#if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM + if (munmap(m->base, m->realsize) == -1) { + return errno; + } + return APR_SUCCESS; +#elif APR_USE_SHMEM_SHMGET + if (shmdt(m->base) == -1) { + return errno; + } + return APR_SUCCESS; +#else + return APR_ENOTIMPL; +#endif + } +} + +APR_DECLARE(apr_status_t) apr_shm_attach(apr_shm_t **m, + const char *filename, + apr_pool_t *pool) +{ + if (filename == NULL) { + /* It doesn't make sense to attach to a segment if you don't know + * the filename. */ + return APR_EINVAL; + } + else { +#if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM + apr_shm_t *new_m; + apr_status_t status; + int tmpfd; + apr_file_t *file; /* file where metadata is stored */ + apr_size_t nbytes; + + new_m = apr_palloc(pool, sizeof(apr_shm_t)); + new_m->pool = pool; + new_m->filename = apr_pstrdup(pool, filename); +#if APR_USE_SHMEM_MMAP_SHM + const char *shm_name = make_shm_open_safe_name(filename, pool); + + /* FIXME: SysV uses 0600... should we? */ + tmpfd = shm_open(shm_name, O_RDWR, 0644); + if (tmpfd == -1) { + return errno; + } + + status = apr_os_file_put(&file, &tmpfd, + APR_READ | APR_WRITE, + pool); + if (status != APR_SUCCESS) { + return status; + } + +#elif APR_USE_SHMEM_MMAP_TMP + status = apr_file_open(&file, filename, + APR_READ | APR_WRITE, + APR_OS_DEFAULT, pool); + if (status != APR_SUCCESS) { + return status; + } + status = apr_os_file_get(&tmpfd, file); + if (status != APR_SUCCESS) { + return status; + } +#else + return APR_ENOTIMPL; +#endif + + nbytes = sizeof(new_m->realsize); + status = apr_file_read(file, (void *)&(new_m->realsize), + &nbytes); + if (status != APR_SUCCESS) { + return status; + } + + status = apr_os_file_get(&tmpfd, file); + if (status != APR_SUCCESS) { + apr_file_close(file); /* ignore errors, we're failing */ + apr_file_remove(new_m->filename, new_m->pool); + return status; + } + + new_m->reqsize = new_m->realsize - sizeof(apr_size_t); + + new_m->base = mmap(NULL, new_m->realsize, PROT_READ | PROT_WRITE, + MAP_SHARED, tmpfd, 0); + /* FIXME: check for errors */ + + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } + + /* metadata isn't part of the usable segment */ + new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t)); + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_attach, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#elif APR_USE_SHMEM_SHMGET + apr_shm_t *new_m; + apr_status_t status; + apr_file_t *file; /* file where metadata is stored */ + apr_size_t nbytes; + + new_m = apr_palloc(pool, sizeof(apr_shm_t)); + + status = apr_file_open(&file, filename, + APR_FOPEN_READ, APR_OS_DEFAULT, pool); + if (status != APR_SUCCESS) { + return status; + } + + nbytes = sizeof(new_m->reqsize); + status = apr_file_read(file, (void *)&(new_m->reqsize), + &nbytes); + if (status != APR_SUCCESS) { + return status; + } + status = apr_file_close(file); + if (status != APR_SUCCESS) { + return status; + } + + new_m->filename = apr_pstrdup(pool, filename); + new_m->pool = pool; + new_m->shmkey = our_ftok(filename); + if (new_m->shmkey == (key_t)-1) { + return errno; + } + if ((new_m->shmid = shmget(new_m->shmkey, 0, SHM_R | SHM_W)) == -1) { + return errno; + } + if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) { + return errno; + } + new_m->usable = new_m->base; + new_m->realsize = new_m->reqsize; + + apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_attach, + apr_pool_cleanup_null); + *m = new_m; + return APR_SUCCESS; + +#else + return APR_ENOTIMPL; +#endif + } +} + +APR_DECLARE(apr_status_t) apr_shm_attach_ex(apr_shm_t **m, + const char *filename, + apr_pool_t *pool, + apr_int32_t flags) +{ + return apr_shm_attach(m, filename, pool); +} + +APR_DECLARE(apr_status_t) apr_shm_detach(apr_shm_t *m) +{ + apr_status_t rv = shm_cleanup_attach(m); + apr_pool_cleanup_kill(m->pool, m, shm_cleanup_attach); + return rv; +} + +APR_DECLARE(void *) apr_shm_baseaddr_get(const apr_shm_t *m) +{ + return m->usable; +} + +APR_DECLARE(apr_size_t) apr_shm_size_get(const apr_shm_t *m) +{ + return m->reqsize; +} + +APR_PERMS_SET_IMPLEMENT(shm) +{ +#if APR_USE_SHMEM_SHMGET || APR_USE_SHMEM_SHMGET_ANON + struct shmid_ds shmbuf; + int shmid; + apr_shm_t *m = (apr_shm_t *)theshm; + + if ((shmid = shmget(m->shmkey, 0, SHM_R | SHM_W)) == -1) { + return errno; + } + shmbuf.shm_perm.uid = uid; + shmbuf.shm_perm.gid = gid; + shmbuf.shm_perm.mode = apr_unix_perms2mode(perms); + if (shmctl(shmid, IPC_SET, &shmbuf) == -1) { + return errno; + } + return APR_SUCCESS; +#else + return APR_ENOTIMPL; +#endif +} + +APR_POOL_IMPLEMENT_ACCESSOR(shm) + +APR_DECLARE(apr_status_t) apr_os_shm_get(apr_os_shm_t *osshm, + apr_shm_t *shm) +{ + return APR_ENOTIMPL; +} + +APR_DECLARE(apr_status_t) apr_os_shm_put(apr_shm_t **m, + apr_os_shm_t *osshm, + apr_pool_t *pool) +{ + return APR_ENOTIMPL; +} + |