diff options
Diffstat (limited to 'relocation.c')
| -rw-r--r-- | relocation.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/relocation.c b/relocation.c new file mode 100644 index 0000000..13ae799 --- /dev/null +++ b/relocation.c @@ -0,0 +1,237 @@ +#include "spm.h" + +int replace_text(char *data, const char *spattern, const char *sreplacement) { + char *tmp = data; + size_t data_len = strlen(data); + size_t spattern_len = strlen(spattern); + size_t sreplacement_len = strlen(sreplacement); + + if (sreplacement_len > spattern_len) { + fprintf(stderr, "replacement string too long\n"); + return -1; + } + + while (*tmp != '\0') { + if (strncmp(tmp, spattern, spattern_len) == 0) { + memmove(tmp, sreplacement, sreplacement_len); + memmove(tmp + sreplacement_len, tmp + spattern_len, data_len - spattern_len); + } + tmp++; + } + return 0; +} + +/** + * Replace all occurrences of `oldstr` in file `path` with `newstr` + * @param filename + * @param oldstr + * @param newstr + * @return success=0, failure=-1, or value of `ferror()` + */ +int file_replace_text(char *filename, const char *spattern, const char *sreplacement) { + char data[BUFSIZ]; + char tempfile[PATH_MAX]; + FILE *fp = NULL; + if ((fp = fopen(filename, "r")) == NULL) { + perror(filename); + return -1; + } + + sprintf(tempfile, "%s.spmfrt", filename); + FILE *tfp = NULL; + if ((tfp = fopen(tempfile, "w+")) == NULL) { + perror(tempfile); + return -1; + } + + // Zero the data buffer + memset(data, '\0', BUFSIZ); + while(fgets(data, BUFSIZ, fp) != NULL) { + replace_text(data, spattern, sreplacement); + fprintf(tfp, "%s", data); + } + fclose(fp); + rewind(tfp); + + // Truncate the original file + if ((fp = fopen(filename, "w+")) == NULL) { + perror(filename); + return -1; + } + // Zero the data buffer once more + memset(data, '\0', BUFSIZ); + // Dump the contents of the temporary file into the original file + while(fgets(data, BUFSIZ, tfp) != NULL) { + fprintf(fp, "%s", data); + } + fclose(fp); + fclose(tfp); + + // Remove temporary file + unlink(tempfile); + return 0; +} + +/** + * Free memory allocated by `prefixes_read` function + * @param entry array of RelocationEntry + */ +void prefixes_free(RelocationEntry **entry) { + if (!entry) { + return; + } + for (int i = 0; entry[i] != NULL; i++) { + if (entry[i]->prefix) free(entry[i]->prefix); + if (entry[i]->path) free(entry[i]->path); + if (entry[i]) free(entry[i]); + } + free(entry); +} + +/** + * Parse a prefix file + * + * The file format is as follows: + * + * ~~~ + * #prefix + * path + * #prefix + * path + * #...N + * ...N + * ~~~ + * @param filename + * @return success=array of RelocationEntry, failure=NULL + */ +RelocationEntry **prefixes_read(const char *filename) { + size_t i = 0; + int record_count = 0; + int parity = 0; + FILE *fp = fopen(filename, "r"); + if (!fp) { + fprintf(SYSERROR); + return NULL; + } + RelocationEntry **entry = NULL; + char line[BUFSIZ]; + memset(line, '\0', BUFSIZ); + + while (fgets(line, BUFSIZ, fp) != NULL) { + if (isempty(line)) { + continue; + } + record_count++; + } + rewind(fp); + + // Initialize the relocation entry array + if (record_count == 0) { + return NULL; + } + + parity = record_count % 2; + if (parity != 0) { + fprintf(stderr, "%s: records are not divisible by 2 (got: %d %% 2 = %d)\n", filename, record_count, parity); + return NULL; + } + record_count /= 2; + + entry = (RelocationEntry **)calloc(record_count + 1, sizeof(RelocationEntry *)); + if (!entry) { + return NULL; + } + for (int i = 0; i < record_count; i++) { + entry[i] = (RelocationEntry *) calloc(1, sizeof(RelocationEntry)); + if (!entry[i]) { + return NULL; + } + } + + int do_prefix = 0; + int do_path = 0; + while (fgets(line, BUFSIZ, fp) != NULL) { + char *wtf = line; + if (isempty(line)) { + continue; + } + if (startswith(line, "#") == 0) { + do_prefix = 1; + } + else { + do_path = 1; + } + + // Allocate a relocation record + if (!entry[i]) { + fclose(fp); + return NULL; + } + + + if (do_prefix) { + // Populate prefix data (a prefix starts with a #) + entry[i]->prefix = (char *) calloc(strlen(line) + 1, sizeof(char)); + if (!entry[i]->prefix) { + fclose(fp); + return NULL; + } + strncpy(entry[i]->prefix, line, strlen(line)); + // Remove prefix delimiter and whitespace + strchrdel(entry[i]->prefix, "#"); + entry[i]->prefix = strip(entry[i]->prefix); + do_prefix = 0; + continue; + } + + else if (do_path) { + // Populate path data + entry[i]->path = (char *) calloc(strlen(line) + 1, sizeof(char)); + if (!entry[i]->path) { + fclose(fp); + return NULL; + } + strncpy(entry[i]->path, line, strlen(line)); + entry[i]->path = strip(entry[i]->path); + do_path = 0; + } + i++; + } + fclose(fp); + return entry; +} + +int relocate(const char *_filename, const char *_oldstr, const char *_newstr) { + int returncode; + Process *proc = NULL; + char *oldstr = strdup(_oldstr); + char *newstr = strdup(_newstr); + char *filename = strdup(_filename); + char cmd[PATH_MAX]; + + memset(cmd, '\0', sizeof(cmd)); + sprintf(cmd, "reloc \"%s\" \"%s\" \"%s\" \"%s\"", oldstr, newstr, filename, filename); + + // sanitize command + strchrdel(cmd, "&;|"); + + shell(&proc, SHELL_OUTPUT, cmd); + if (!proc) { + free(oldstr); + free(newstr); + free(filename); + return -1; + } + + returncode = proc->returncode; + if (returncode != 0 && proc->output) { + fprintf(stderr, proc->output); + } + + shell_free(proc); + free(oldstr); + free(newstr); + free(filename); + return returncode; +} + |