X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fmemfd.c;h=b55817795162637a80061cca63628f30c003f463;hb=47f0f4eb1d79ec37dfbe6a382817c0384b106373;hp=d94c6268ddf5e376df3ea29956b22b4c1ce8d9b7;hpb=23972f4244f7609658c2a17f85508d50e4739990;p=elogind.git diff --git a/src/shared/memfd.c b/src/shared/memfd.c index d94c6268d..b55817795 100644 --- a/src/shared/memfd.c +++ b/src/shared/memfd.c @@ -25,37 +25,21 @@ #include #include +#ifdef HAVE_LINUX_MEMFD_H +# include +#endif + #include "util.h" #include "bus-label.h" -#include "missing.h" #include "memfd.h" +#include "utf8.h" +#include "missing.h" -#include "sd-bus.h" - -struct sd_memfd { - int fd; - FILE *f; -}; - -int sd_memfd_new(sd_memfd **m, const char *name) { - +int memfd_new(const char *name) { _cleanup_free_ char *g = NULL; - sd_memfd *n; - - assert_return(m, -EINVAL); - - if (name) { - /* The kernel side is pretty picky about the character - * set here, let's do the usual bus escaping to deal - * with that. */ - - g = bus_label_escape(name); - if (!g) - return -ENOMEM; - - name = g; + int fd; - } else { + if (!name) { char pr[17] = {}; /* If no name is specified we generate one. We include @@ -69,7 +53,7 @@ int sd_memfd_new(sd_memfd **m, const char *name) { else { _cleanup_free_ char *e = NULL; - e = bus_label_escape(pr); + e = utf8_escape_invalid(pr); if (!e) return -ENOMEM; @@ -81,105 +65,29 @@ int sd_memfd_new(sd_memfd **m, const char *name) { } } - n = new0(struct sd_memfd, 1); - if (!n) - return -ENOMEM; - - n->fd = memfd_create(name, MFD_ALLOW_SEALING); - if (n->fd < 0) { - free(n); - return -errno; - } - - *m = n; - return 0; -} - -int sd_memfd_new_from_fd(sd_memfd **m, int fd) { - sd_memfd *n; - int r; - - assert_return(m, -EINVAL); - assert_return(fd >= 0, -EINVAL); - - /* Check if this is a sealable fd. The kernel sets F_SEAL_SEAL on memfds - * that don't support sealing, so check for that, too. A file with - * *only* F_SEAL_SEAL set is the same as a random shmem file, so no - * reason to allow opening it as memfd. */ - r = fcntl(fd, F_GET_SEALS); - if (r < 0 || r == F_SEAL_SEAL) - return -ENOTTY; - - n = new0(struct sd_memfd, 1); - if (!n) - return -ENOMEM; - - n->fd = fd; - *m = n; - - return 0; -} - -void sd_memfd_free(sd_memfd *m) { - if (!m) - return; - - if (m->f) - fclose(m->f); - else - safe_close(m->fd); - - free(m); -} - -int sd_memfd_get_fd(sd_memfd *m) { - assert_return(m, -EINVAL); - - return m->fd; -} - -int sd_memfd_get_file(sd_memfd *m, FILE **f) { - assert_return(m, -EINVAL); - assert_return(f, -EINVAL); - - if (!m->f) { - m->f = fdopen(m->fd, "r+"); - if (!m->f) - return -errno; - } - - *f = m->f; - return 0; -} - -int sd_memfd_dup_fd(sd_memfd *m) { - int fd; - - assert_return(m, -EINVAL); - - fd = fcntl(m->fd, F_DUPFD_CLOEXEC, 3); + fd = memfd_create(name, MFD_ALLOW_SEALING | MFD_CLOEXEC); if (fd < 0) return -errno; return fd; } -int sd_memfd_map(sd_memfd *m, uint64_t offset, size_t size, void **p) { +int memfd_map(int fd, uint64_t offset, size_t size, void **p) { void *q; int sealed; - assert_return(m, -EINVAL); - assert_return(size > 0, -EINVAL); - assert_return(p, -EINVAL); + assert(fd >= 0); + assert(size > 0); + assert(p); - sealed = sd_memfd_get_sealed(m); + sealed = memfd_get_sealed(fd); if (sealed < 0) return sealed; if (sealed) - q = mmap(NULL, size, PROT_READ, MAP_PRIVATE, m->fd, offset); + q = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, offset); else - q = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, m->fd, offset); + q = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset); if (q == MAP_FAILED) return -errno; @@ -188,24 +96,24 @@ int sd_memfd_map(sd_memfd *m, uint64_t offset, size_t size, void **p) { return 0; } -int sd_memfd_set_sealed(sd_memfd *m) { +int memfd_set_sealed(int fd) { int r; - assert_return(m, -EINVAL); + assert(fd >= 0); - r = fcntl(m->fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE); + r = fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE); if (r < 0) return -errno; return 0; } -int sd_memfd_get_sealed(sd_memfd *m) { +int memfd_get_sealed(int fd) { int r; - assert_return(m, -EINVAL); + assert(fd >= 0); - r = fcntl(m->fd, F_GET_SEALS); + r = fcntl(fd, F_GET_SEALS); if (r < 0) return -errno; @@ -213,100 +121,54 @@ int sd_memfd_get_sealed(sd_memfd *m) { (F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE); } -int sd_memfd_get_size(sd_memfd *m, uint64_t *sz) { - int r; +int memfd_get_size(int fd, uint64_t *sz) { struct stat stat; + int r; - assert_return(m, -EINVAL); - assert_return(sz, -EINVAL); + assert(fd >= 0); + assert(sz); - r = fstat(m->fd, &stat); + r = fstat(fd, &stat); if (r < 0) return -errno; *sz = stat.st_size; - return r; + return 0; } -int sd_memfd_set_size(sd_memfd *m, uint64_t sz) { +int memfd_set_size(int fd, uint64_t sz) { int r; - assert_return(m, -EINVAL); + assert(fd >= 0); - r = ftruncate(m->fd, sz); + r = ftruncate(fd, sz); if (r < 0) return -errno; - return r; + return 0; } -int sd_memfd_new_and_map(sd_memfd **m, const char *name, size_t sz, void **p) { - sd_memfd *n; +int memfd_new_and_map(const char *name, size_t sz, void **p) { + _cleanup_close_ int fd = -1; int r; - r = sd_memfd_new(&n, name); - if (r < 0) - return r; + assert(sz > 0); + assert(p); - r = sd_memfd_set_size(n, sz); - if (r < 0) { - sd_memfd_free(n); - return r; - } + fd = memfd_new(name); + if (fd < 0) + return fd; - r = sd_memfd_map(n, 0, sz, p); - if (r < 0) { - sd_memfd_free(n); + r = memfd_set_size(fd, sz); + if (r < 0) return r; - } - *m = n; - return 0; -} - -int sd_memfd_get_name(sd_memfd *m, char **name) { - char path[sizeof("/proc/self/fd/") + DECIMAL_STR_MAX(int)], buf[FILENAME_MAX+1], *e; - const char *delim, *end; - _cleanup_free_ char *n = NULL; - ssize_t k; - - assert_return(m, -EINVAL); - assert_return(name, -EINVAL); - - sprintf(path, "/proc/self/fd/%i", m->fd); - - k = readlink(path, buf, sizeof(buf)); - if (k < 0) - return -errno; - - if ((size_t) k >= sizeof(buf)) - return -E2BIG; - - buf[k] = 0; - - delim = strstr(buf, ":["); - if (!delim) - return -EIO; - - delim = strchr(delim + 2, ':'); - if (!delim) - return -EIO; - - delim++; - - end = strchr(delim, ']'); - if (!end) - return -EIO; - - n = strndup(delim, end - delim); - if (!n) - return -ENOMEM; - - e = bus_label_unescape(n); - if (!e) - return -ENOMEM; + r = memfd_map(fd, 0, sz, p); + if (r < 0) + return r; - *name = e; + r = fd; + fd = -1; - return 0; + return r; }