strlcat.c
#include <sys/types.h> #include <string.h> /* * Appends src to string dst of size dsize (unlike strncat, dsize is the * full size of dst, not space left). At most dsize-1 characters * will be copied. Always NUL terminates (unless dsize <= strlen(dst)). * Returns strlen(src) + MIN(dsize, strlen(initial dst)). * If retval >= dsize, truncation occurred. */ size_t strlcat(char *dst, const char *src, size_t dsize) { const char *odst = dst; const char *osrc = src; size_t n = dsize; size_t dlen; /* Find the end of dst and adjust bytes left but don't go past end. */ while (n-- != 0 && *dst != '\0') dst++; dlen = dst - odst; n = dsize - dlen; if (n-- == 0) return(dlen + strlen(src)); while (*src != '\0') { if (n != 0) { *dst++ = *src; n--; } src++; } *dst = '\0'; return(dlen + (src - osrc)); /* count does not include NUL */ }
测试代码 strlcattest.c
#include <sys/types.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <setjmp.h> #include <signal.h> #include <unistd.h> volatile sig_atomic_t got_signal; sigjmp_buf jmpenv; void handler(int signo) { got_signal = signo; siglongjmp(jmpenv, 1); } int main(int argc, char *argv[]) { char *buf, *cp, *ep; struct sigaction sa; size_t len, bufsize; int failures = 0; bufsize = getpagesize(); /* trigger guard pages easily */ buf = malloc(bufsize); if (buf == NULL) { fprintf(stderr, "unable to allocate memory\n"); return 1; } memset(buf, 'z', bufsize); ep = buf + bufsize; /* Test appending to an unterminated string. */ len = strlcat(buf, "abcd", bufsize); if (len != 4 + bufsize) { fprintf(stderr, "strlcat: failed unterminated buffer test (1a)\n"); failures++; } /* Make sure we only wrote where expected. */ for (cp = buf; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcat: failed unterminated buffer test (1b)\n"); failures++; break; } } /* Test appending to a full string. */ ep[-1] = '\0'; len = strlcat(buf, "abcd", bufsize); if (len != 4 + bufsize - 1) { fprintf(stderr, "strlcat: failed full buffer test (2a)\n"); failures++; } /* Make sure we only wrote where expected. */ for (cp = buf; cp < ep - 1; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcat: failed full buffer test (2b)\n"); failures++; break; } } /* Test appending to an empty string. */ ep[-1] = 'z'; buf[0] = '\0'; len = strlcat(buf, "abcd", bufsize); if (len != 4) { fprintf(stderr, "strlcat: failed empty buffer test (3a)\n"); failures++; } /* Make sure we only wrote where expected. */ if (memcmp(buf, "abcd", sizeof("abcd")) != 0) { fprintf(stderr, "strlcat: failed empty buffer test (3b)\n"); failures++; } for (cp = buf + len + 1; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcat: failed empty buffer test (3c)\n"); failures++; break; } } /* Test appending to a NUL-terminated string. */ memcpy(buf, "abcd", sizeof("abcd")); len = strlcat(buf, "efgh", bufsize); if (len != 8) { fprintf(stderr, "strlcat: failed empty buffer test (4a)\n"); failures++; } /* Make sure we only wrote where expected. */ if (memcmp(buf, "abcdefgh", sizeof("abcdefgh")) != 0) { fprintf(stderr, "strlcat: failed empty buffer test (4b)\n"); failures++; } for (cp = buf + len + 1; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcat: failed empty buffer test (4c)\n"); failures++; break; } } /* * The following tests should result in SIGSEGV, however some * systems may erroneously report SIGBUS. * These tests assume that strlcat() is signal-safe. */ memset(&sa, 0, sizeof(sa)); sigemptyset(&sa.sa_mask); sa.sa_handler = handler; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); /* Test copying to a NULL buffer with non-zero size. */ got_signal = 0; if (sigsetjmp(jmpenv, 1) == 0) { len = strlcat(NULL, "abcd", sizeof(buf)); fprintf(stderr, "strlcat: failed NULL dst test (5a), " "expected signal %d, got len %zu\n", SIGSEGV, len); failures++; } else if (got_signal != SIGSEGV) { fprintf(stderr, "strlcat: failed NULL dst test (5b), " "expected signal %d, got %d\n", SIGSEGV, got_signal); failures++; } /* Test copying from a NULL src. */ memcpy(buf, "abcd", sizeof("abcd")); got_signal = 0; if (sigsetjmp(jmpenv, 1) == 0) { len = strlcat(buf, NULL, sizeof(buf)); fprintf(stderr, "strlcat: failed NULL src test (6a), " "expected signal %d, got len %zu\n", SIGSEGV, len); failures++; } else if (got_signal != SIGSEGV) { fprintf(stderr, "strlcat: failed NULL src test (6b), " "expected signal %d, got %d\n", SIGSEGV, got_signal); failures++; } return failures; }
strlcpy.c
#include <sys/types.h> #include <string.h> /* * Copy string src to buffer dst of size dsize. At most dsize-1 * chars will be copied. Always NUL terminates (unless dsize == 0). * Returns strlen(src); if retval >= dsize, truncation occurred. */ size_t strlcpy(char *dst, const char *src, size_t dsize) { const char *osrc = src; size_t nleft = dsize; /* Copy as many bytes as will fit. */ if (nleft != 0) { while (--nleft != 0) { if ((*dst++ = *src++) == '\0') break; } } /* Not enough room in dst, add NUL and traverse rest of src. */ if (nleft == 0) { if (dsize != 0) *dst = '\0'; /* NUL-terminate dst */ while (*src++) ; } return(src - osrc - 1); /* count does not include NUL */ }
测试代码strlcpy.c
/* $OpenBSD: strlcpytest.c,v 1.4 2021/09/01 09:26:32 jasper Exp $ */ /* * Copyright (c) 2014 Todd C. Miller <millert@openbsd.org> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <sys/types.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <signal.h> #include <setjmp.h> #include <unistd.h> volatile sig_atomic_t got_signal; sigjmp_buf jmpenv; void handler(int signo) { got_signal = signo; siglongjmp(jmpenv, 1); } int main(int argc, char *argv[]) { char *buf, *buf2, *cp, *ep; struct sigaction sa; size_t len, bufsize; int failures = 0; bufsize = getpagesize(); /* trigger guard pages easily */ buf = malloc(bufsize); buf2 = malloc(bufsize); if (buf == NULL || buf2 == NULL) { fprintf(stderr, "unable to allocate memory\n"); return 1; } memset(buf, 'z', bufsize); ep = buf + bufsize; /* Test copying to a zero-length NULL buffer. */ len = strlcpy(NULL, "abcd", 0); if (len != 4) { fprintf(stderr, "strlcpy: failed zero-length buffer test (1a)\n"); failures++; } /* Test copying small string to a large buffer. */ len = strlcpy(buf, "abcd", bufsize); if (len != 4) { fprintf(stderr, "strlcpy: failed large buffer test (2a)\n"); failures++; } /* Make sure we only wrote where expected. */ if (memcmp(buf, "abcd", sizeof("abcd")) != 0) { fprintf(stderr, "strlcpy: failed large buffer test (2b)\n"); failures++; } for (cp = buf + len + 1; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcpy: failed large buffer test (2c)\n"); failures++; break; } } /* Test copying large string to a small buffer. */ memset(buf, 'z', bufsize); memset(buf2, 'x', bufsize - 1); buf2[bufsize - 1] = '\0'; len = strlcpy(buf, buf2, bufsize / 2); if (len != bufsize - 1) { fprintf(stderr, "strlcpy: failed small buffer test (3a)\n"); failures++; } /* Make sure we only wrote where expected. */ len = (bufsize / 2) - 1; if (memcmp(buf, buf2, len) != 0 || buf[len] != '\0') { fprintf(stderr, "strlcpy: failed small buffer test (3b)\n"); failures++; } for (cp = buf + len + 1; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcpy: failed small buffer test (3c)\n"); failures++; break; } } /* Test copying to a 1-byte buffer. */ memset(buf, 'z', bufsize); len = strlcpy(buf, "abcd", 1); if (len != 4) { fprintf(stderr, "strlcpy: failed 1-byte buffer test (4a)\n"); failures++; } /* Make sure we only wrote where expected. */ if (buf[0] != '\0') { fprintf(stderr, "strlcpy: failed 1-byte buffer test (4b)\n"); failures++; } for (cp = buf + 1; cp < ep; cp++) { if (*cp != 'z') { fprintf(stderr, "strlcpy: failed 1-byte buffer test (4c)\n"); failures++; break; } } /* * The following tests should result in SIGSEGV, however some * systems may erroneously report SIGBUS. * These tests assume that strlcpy() is signal-safe. */ memset(&sa, 0, sizeof(sa)); sigemptyset(&sa.sa_mask); sa.sa_handler = handler; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); /* Test copying to a NULL buffer with non-zero size. */ got_signal = 0; if (sigsetjmp(jmpenv, 1) == 0) { len = strlcpy(NULL, "abcd", sizeof(buf)); fprintf(stderr, "strlcpy: failed NULL dst test (5a), " "expected signal %d, got len %zu\n", SIGSEGV, len); failures++; } else if (got_signal != SIGSEGV) { fprintf(stderr, "strlcpy: failed NULL dst test (5b), " "expected signal %d, got %d\n", SIGSEGV, got_signal); failures++; } /* Test copying from a NULL src. */ got_signal = 0; if (sigsetjmp(jmpenv, 1) == 0) { len = strlcpy(buf, NULL, sizeof(buf)); fprintf(stderr, "strlcpy: failed NULL src test (6a), " "expected signal %d, got len %zu\n", SIGSEGV, len); failures++; } else if (got_signal != SIGSEGV) { fprintf(stderr, "strlcpy: failed NULL src test (6b), " "expected signal %d, got %d\n", SIGSEGV, got_signal); failures++; } return failures; }
代码来源：http://ftp.openbsd.org/pub/OpenBSD/7.0/src.tar.gz