Edward O'Callaghan | 774dcff | 2022-06-06 20:01:04 +1000 | [diff] [blame] | 1 | /* Copyright 2020 The Chromium OS Authors. All rights reserved. |
| 2 | * Use of this source code is governed by a BSD-style license that can be |
| 3 | * found in the LICENSE file. |
| 4 | */ |
| 5 | |
| 6 | /* For strdup */ |
| 7 | #define _POSIX_C_SOURCE 200809L |
| 8 | #include <fcntl.h> |
| 9 | #include <limits.h> |
| 10 | #include <stdbool.h> |
| 11 | #include <stdint.h> |
| 12 | #include <stdio.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <string.h> |
| 15 | #include <sys/stat.h> |
| 16 | #include <sys/types.h> |
| 17 | #include <unistd.h> |
| 18 | |
| 19 | #include "common.h" /* from cbfstool for buffer API. */ |
| 20 | #include "subprocess.h" /* from vboot_reference */ |
| 21 | #include "flashrom.h" |
| 22 | |
| 23 | #define FLASHROM_EXEC_NAME "flashrom" |
| 24 | #define FLASHROM_PROGRAMMER_INTERNAL_AP "host" |
| 25 | |
| 26 | /** |
| 27 | * Helper to create a temporary file. |
| 28 | * |
| 29 | * @param path_out An output pointer for the filename. Caller should free. |
| 30 | * |
| 31 | * @return 0 on success, -1 for file open error, or -2 for write error. |
| 32 | */ |
| 33 | static int create_temp_file(char **path_out) |
| 34 | { |
| 35 | int fd; |
| 36 | int rv; |
| 37 | char *path; |
| 38 | mode_t umask_save; |
| 39 | |
| 40 | #if defined(__FreeBSD__) |
| 41 | #define P_tmpdir "/tmp" |
| 42 | #endif |
| 43 | *path_out = NULL; |
| 44 | path = strdup(P_tmpdir "/flashrom.XXXXXX"); |
| 45 | /* Set the umask before mkstemp for security considerations. */ |
| 46 | umask_save = umask(077); |
| 47 | fd = mkstemp(path); |
| 48 | umask(umask_save); |
| 49 | if (fd < 0) { |
| 50 | rv = -1; |
| 51 | goto fail; |
| 52 | } |
| 53 | |
| 54 | close(fd); |
| 55 | *path_out = path; |
| 56 | |
| 57 | return 0; |
| 58 | fail: |
| 59 | free(path); |
| 60 | return rv; |
| 61 | } |
| 62 | |
| 63 | static int run_flashrom(const char *const argv[]) |
| 64 | { |
| 65 | int status = subprocess_run(argv, &subprocess_null, &subprocess_null, |
| 66 | &subprocess_null); |
| 67 | if (status) { |
| 68 | fprintf(stderr, "Flashrom invocation failed (exit status %d):", |
| 69 | status); |
| 70 | for (const char *const *argp = argv; *argp; argp++) |
| 71 | fprintf(stderr, " %s", *argp); |
| 72 | fprintf(stderr, "\n"); |
| 73 | return -1; |
| 74 | } |
| 75 | |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | int flashrom_host_read(struct buffer *buffer, const char *region) |
| 80 | { |
| 81 | char *tmpfile; |
| 82 | char region_param[PATH_MAX]; |
| 83 | int rv; |
| 84 | |
| 85 | if (create_temp_file(&tmpfile) != 0) |
| 86 | return -1; |
| 87 | if (region) |
| 88 | snprintf(region_param, sizeof(region_param), "%s:%s", region, |
| 89 | tmpfile); |
| 90 | const char *const argv[] = { |
| 91 | FLASHROM_EXEC_NAME, |
| 92 | "-p", |
| 93 | FLASHROM_PROGRAMMER_INTERNAL_AP, |
| 94 | "-r", |
| 95 | region ? "-i" : tmpfile, |
| 96 | region ? region_param : NULL, |
| 97 | NULL, |
| 98 | }; |
| 99 | rv = run_flashrom(argv); |
| 100 | if (!rv) |
| 101 | rv = buffer_from_file(buffer, tmpfile); |
| 102 | |
| 103 | unlink(tmpfile); |
| 104 | free(tmpfile); |
| 105 | |
| 106 | return rv; |
| 107 | } |
| 108 | |
| 109 | int flashrom_host_write(struct buffer *buffer, const char *region) |
| 110 | { |
| 111 | char *tmpfile; |
| 112 | char region_param[PATH_MAX]; |
| 113 | int rv; |
| 114 | |
| 115 | if (create_temp_file(&tmpfile) != 0) |
| 116 | return -1; |
| 117 | if (buffer_write_file(buffer, tmpfile) != 0) { |
| 118 | rv = -2; |
| 119 | goto fail; |
| 120 | } |
| 121 | |
| 122 | if (region) |
| 123 | snprintf(region_param, sizeof(region_param), "%s:%s", region, |
| 124 | tmpfile); |
| 125 | const char *const argv[] = { |
| 126 | FLASHROM_EXEC_NAME, |
| 127 | "-p", |
| 128 | FLASHROM_PROGRAMMER_INTERNAL_AP, |
| 129 | "--noverify-all", |
| 130 | "-w", |
| 131 | region ? "-i" : tmpfile, |
| 132 | region ? region_param : NULL, |
| 133 | NULL, |
| 134 | }; |
| 135 | |
| 136 | rv = run_flashrom(argv); |
| 137 | |
| 138 | fail: |
| 139 | unlink(tmpfile); |
| 140 | free(tmpfile); |
| 141 | |
| 142 | return rv; |
| 143 | } |