diff options
| -rw-r--r-- | usr.bin/fetch/fetch.c | 98 |
1 files changed, 71 insertions, 27 deletions
diff --git a/usr.bin/fetch/fetch.c b/usr.bin/fetch/fetch.c index a8ef3a6..3d8c22e 100644 --- a/usr.bin/fetch/fetch.c +++ b/usr.bin/fetch/fetch.c @@ -245,17 +245,20 @@ fetch(char *URL, const char *path) { struct url *url; struct url_stat us; - struct stat sb; + struct stat sb, nsb; struct xferstat xs; FILE *f, *of; size_t size, wr; off_t count; char flags[8]; + const char *slash; + char *tmppath; int r; u_int timeout; u_char *ptr; f = of = NULL; + tmppath = NULL; /* parse URL */ if ((url = fetchParseURL(URL)) == NULL) { @@ -336,12 +339,13 @@ fetch(char *URL, const char *path) * file was a truncated copy of the remote file; we can drop * the connection later if we change our minds. */ - if ((r_flag || m_flag) && !o_stdout && stat(path, &sb) != -1) { - if (r_flag) - url->offset = sb.st_size; - } else { - sb.st_size = -1; + sb.st_size = -1; + if (!o_stdout && stat(path, &sb) == -1 && errno != ENOENT) { + warnx("%s: stat()", path); + goto failure; } + if (!o_stdout && r_flag && S_ISREG(sb.st_mode)) + url->offset = sb.st_size; /* start the transfer */ if ((f = fetchXGet(url, &us, flags)) == NULL) { @@ -387,7 +391,7 @@ fetch(char *URL, const char *path) if (o_stdout) { /* output to stdout */ of = stdout; - } else if (sb.st_size != -1) { + } else if (r_flag && sb.st_size != -1) { /* resume mode, local file exists */ if (!F_flag && us.mtime && sb.st_mtime != us.mtime) { /* no match! have to refetch */ @@ -398,13 +402,6 @@ fetch(char *URL, const char *path) "does not match remote", path); goto failure_keep; } - url->offset = 0; - if ((f = fetchXGet(url, &us, flags)) == NULL) { - warnx("%s: %s", path, fetchLastErrString); - goto failure; - } - if (sigint) - goto signal; } else { if (us.size == sb.st_size) /* nothing to do */ @@ -416,34 +413,73 @@ fetch(char *URL, const char *path) (long long)sb.st_size, (long long)us.size); goto failure; } - /* we got it, open local file and seek to offset */ - /* - * XXX there's a race condition here - the - * file we open is not necessarily the same as - * the one we stat()'ed earlier... - */ + /* we got it, open local file */ if ((of = fopen(path, "a")) == NULL) { warn("%s: fopen()", path); goto failure; } - if (fseek(of, url->offset, SEEK_SET) == -1) { - warn("%s: fseek()", path); + /* check that it didn't move under our feet */ + if (fstat(fileno(of), &nsb) == -1) { + /* can't happen! */ + warn("%s: fstat()", path); goto failure; } + if (nsb.st_dev != sb.st_dev || + nsb.st_ino != nsb.st_ino || + nsb.st_size != sb.st_size) { + warnx("%s: file has changed", path); + fclose(of); + of = NULL; + sb = nsb; + } } - } - if (m_flag && sb.st_size != -1) { + } else if (m_flag && sb.st_size != -1) { /* mirror mode, local file exists */ if (sb.st_size == us.size && sb.st_mtime == us.mtime) goto success; } - if (!of) { + + if (of == NULL) { /* * We don't yet have an output file; either this is a * vanilla run with no special flags, or the local and * remote files didn't match. */ - if ((of = fopen(path, "w")) == NULL) { + + if (url->offset != 0) { + /* + * We tried to restart a transfer, but for + * some reason gave up - so we have to restart + * from scratch if we want the whole file + */ + url->offset = 0; + if ((f = fetchXGet(url, &us, flags)) == NULL) { + warnx("%s: %s", path, fetchLastErrString); + goto failure; + } + if (sigint) + goto signal; + } + + /* construct a temp file name */ + if (sb.st_size != -1 && S_ISREG(sb.st_mode)) { + if ((slash = strrchr(path, '/')) == NULL) + slash = path; + else + ++slash; + asprintf(&tmppath, "%.*s.fetch.XXXXXX.%s", + slash - path, path, slash); + } + + if (tmppath != NULL) { + mkstemps(tmppath, strlen(slash) + 1); + warnx("tmppath: %s", tmppath); + of = fopen(tmppath, "w"); + } else { + of = fopen(path, "w"); + } + + if (of == NULL) { warn("%s: open()", path); goto failure; } @@ -545,11 +581,17 @@ fetch(char *URL, const char *path) success: r = 0; + if (tmppath != NULL && rename(tmppath, path) == -1) { + warn("%s: rename()", path); + goto failure_keep; + } goto done; failure: if (of && of != stdout && !R_flag && !r_flag) if (stat(path, &sb) != -1 && (sb.st_mode & S_IFREG)) - unlink(path); + unlink(tmppath ? tmppath : path); + if (R_flag && tmppath != NULL && sb.st_size == -1) + rename(tmppath, path); /* ignore errors here */ failure_keep: r = -1; goto done; @@ -560,6 +602,8 @@ fetch(char *URL, const char *path) fclose(of); if (url) fetchFreeURL(url); + if (tmppath != NULL) + free(tmppath); return r; } |
