diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/logic/tpax_archive_append.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/logic/tpax_archive_append.c b/src/logic/tpax_archive_append.c new file mode 100644 index 0000000..ce357b5 --- /dev/null +++ b/src/logic/tpax_archive_append.c @@ -0,0 +1,174 @@ +/******************************************************/ +/* tpax: a topological pax implementation */ +/* Copyright (C) 2020 Z. Gilboa */ +/* Released under GPLv2 and GPLv3; see COPYING.TPAX. */ +/******************************************************/ + +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <grp.h> +#include <pwd.h> +#include <sys/stat.h> + +#include <tpax/tpax.h> +#include <tpax/tpax_specs.h> +#include "tpax_driver_impl.h" +#include "tpax_tmpfile_impl.h" +#include "tpax_errinfo_impl.h" + +#ifndef ssizeof +#define ssizeof(x) (ssize_t)(sizeof(x)) +#endif + +static int tpax_archive_append_memory_data( + int fdout, + void * buf, + ssize_t nbytes) +{ + ssize_t ret; + char * ch; + + for (ch=buf; nbytes; ch+=ret) { + ret = write(fdout,ch,nbytes); + + while ((ret < 0) && (errno == EINTR)) + ret = write(fdout,ch,nbytes); + + if (ret < 0) + return ret; + + nbytes -= ret; + } + + return 0; +} + +static int tpax_archive_append_pad( + int fdout, + const struct stat * st) +{ + ssize_t nbytes; + char buf[512]; + + nbytes = st->st_size; + nbytes += 0x1ff; + nbytes |= 0x1ff; + nbytes ^= 0x1ff; + nbytes -= st->st_size; + + memset(buf,0,nbytes); + + return tpax_archive_append_memory_data( + fdout,buf,nbytes); +} + +int tpax_archive_append( + const struct tpax_driver_ctx * dctx, + const struct tpax_unit_ctx * uctx) +{ + struct tpax_ustar_header uhdr; + int fdout; + int fdtmp; + ssize_t nread; + ssize_t nbytes; + void * buf; + size_t buflen; + size_t cmplen; + void * membuf; + char sbuf[2048]; + + /* record errors */ + tpax_driver_set_ectx( + dctx,0, + *uctx->path); + + /* driver */ + fdout = tpax_driver_fdout(dctx); + + /* header */ + if (tpax_init_ustar_header( + dctx,*uctx->path,uctx->st, + *uctx->link,&uhdr) < 0) + return TPAX_NESTED_ERROR(dctx); + + /* buffer */ + membuf = 0; + fdtmp = -1; + + if ((buf = tpax_get_driver_anon_map_addr(dctx,&buflen))) + if (buflen >= (cmplen = uctx->st->st_size)) + membuf = buf; + + if (ssizeof(sbuf) >= (uctx->st->st_size)) + membuf = sbuf; + + /* snapshot */ + if (membuf) { + if (tpax_file_create_memory_snapshot( + dctx,*uctx->path, + uctx->st,membuf) < 0) + return TPAX_NESTED_ERROR(dctx); + } else { + if ((fdtmp = tpax_file_create_tmpfs_snapshot( + dctx,*uctx->path, + uctx->st)) < 0) + return TPAX_NESTED_ERROR(dctx); + + if (lseek(fdtmp,0,SEEK_SET) < 0) + return TPAX_SYSTEM_ERROR(dctx); + } + + /* append header */ + if (tpax_archive_append_memory_data(fdout,&uhdr,ssizeof(uhdr)) < 0) { + if (fdtmp >= 0) + close(fdtmp); + + return TPAX_SYSTEM_ERROR(dctx); + } + + /* append data from snapshot */ + if (fdtmp >= 0) { + if (!buf) { + buf = sbuf; + buflen = sizeof(sbuf); + } + + for (nread=0; nread<uctx->st->st_size; ) { + nbytes = read(fdtmp,buf,buflen); + + while ((nbytes < 0) && (errno == EINTR)) + nbytes = read(fdtmp,buf,buflen); + + if (nbytes < 0) { + close(fdtmp); + return TPAX_SYSTEM_ERROR(dctx); + + } else if (nbytes == 0) { + close(fdtmp); + return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR); + + } else { + nread += nbytes; + } + + if (tpax_archive_append_memory_data(fdout,buf,nbytes) < 0) { + close(fdtmp); + return TPAX_SYSTEM_ERROR(dctx); + } + } + + close(fdtmp); + } else { + if (tpax_archive_append_memory_data( + fdout,membuf, + uctx->st->st_size) < 0) + return TPAX_SYSTEM_ERROR(dctx); + } + + return tpax_archive_append_pad( + fdout,uctx->st); +} |